This document reviews alternative thermal barrier coatings for diesel engines. It discusses how thermal barrier coatings can increase combustion chamber temperatures, improving engine efficiency and reducing emissions. Several alternative coating materials are described that have properties suitable for thermal barrier coatings, such as low thermal conductivity and high thermal stability at high temperatures. These include zirconates, garnets, yttria stabilized zirconia, and oxides from the alumina-silica-magnesia system like cordierite, forsterite, spinel, and mullite. The document also reviews the potential benefits of thermal barrier coatings, such as reduced fuel consumption and increased engine efficiency, as well as some challenges in fully realizing these benefits.
Investigations on the performance of diesel in an air gap ceramic coated dies...eSAT Journals
This document summarizes an investigation into the performance of a diesel engine with ceramic coatings and different piston materials. A ceramic-coated engine was developed with an air gap between the piston skirt and crown, cylinder liner and jacket, and ceramic coating on the cylinder head and valves. Testing was conducted with aluminum, plain brass, and brass pistons with six grooves. The brass piston with six grooves performed best, increasing exhaust temperature by 5.36% and brake thermal efficiency by 3.16% compared to the brass piston, but also decreased volumetric efficiency more than the other pistons. Overall, the ceramic coatings and brass pistons improved combustion and reduced emissions.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
This document summarizes a study on developing a full mould casting process using polystyrene foam as a pattern. A polystyrene cutting machine was fabricated to cut foam into patterns. An aluminum-silicon alloy was used for casting. Modification was done to improve mechanical properties. Tests found that the casting process produced parts with good shape, mechanical properties, and surface finish using the polystyrene foam pattern and modifier. The full mould casting process allows for complex shapes without draft or flash at lower cost, energy use, and waste compared to other casting methods.
IRJET- Fabrication and Characterization of Hybrid Aluminium Metal Matrix Comp...IRJET Journal
This document describes the fabrication and characterization of a hybrid aluminum metal matrix composite. The composite was created using AA6063 aluminum alloy reinforced with silicon carbide, magnesium, and fly ash particles using stir casting. The goal was to improve the wear rate, tensile strength, compressive strength, and hardness of the composite compared to the unreinforced alloy. Tests were conducted on the composite to evaluate these properties, including ultimate tensile strength testing, wear testing, compressive strength testing, hardness testing, and microstructure analysis. Taguchi's design of experiments method was used to determine the optimum processing parameters to minimize wear rate. The composite showed improved properties over the aluminum alloy alone.
The document describes a project to analyze the effects of applying thermal barrier coatings to diesel locomotive engines. The objectives are to increase power output and efficiency while reducing fuel consumption, emissions, and wear on engine components. The project involves studying engine components, applying thermal barrier coatings, analyzing coatings using simulation software, and reporting on design considerations and results. Thermal barrier coatings aim to insulate components and allow higher operating temperatures to improve performance and lifespan.
IRJET- High Effect of 22Cr10AlY Coating Thickness on Air Hot Corrosion of...IRJET Journal
This document investigates the effect of coating thickness on the oxidation and hot corrosion behavior of nickel-based alloys exposed to air at 850°C and 900°C under cyclic conditions. Nickel-based alloy samples were coated with 22Cr10AlY coatings of thicknesses 50 microns and 100 microns using detonation gun coating. The samples were then subjected to cyclic oxidation testing involving heating for 5 hours at 850°C and 900°C followed by 20 minutes cooling for 10 cycles. Weight change measurements were made to determine the kinetics of oxidation and hot corrosion. Scanning electron microscopy was used to analyze the corroded products. It was observed that the coated nickel alloy with 100 micron coating showed better resistance to oxidation
Thermal Barrier Coating For Gas Turbine EnginesNelsonkandulna
This presentation describes the thermal barrier coating process, its anatomy, types, material selection, failure, and characterization. Thermal barrier coatings (TBCs) were introduced to protect the external surface of gas turbine engine components from thermal resistance and thereby decrease the temperature of the metal surfaces. Yttria stabilized zirconia (YSZ) is one of the most popular and widely used TBC materials as it provides the best performance in high-temperature zones such as diesel engines and gas turbines. The columnar microstructure of YSZ coating provides excellent strain tolerance and adhesion to the coating. Gas turbines are used to power aircraft, trains, ships, electrical generators, pumps, gas compressors, and tanks.
Investigations on the performance of diesel in an air gap ceramic coated dies...eSAT Journals
This document summarizes an investigation into the performance of a diesel engine with ceramic coatings and different piston materials. A ceramic-coated engine was developed with an air gap between the piston skirt and crown, cylinder liner and jacket, and ceramic coating on the cylinder head and valves. Testing was conducted with aluminum, plain brass, and brass pistons with six grooves. The brass piston with six grooves performed best, increasing exhaust temperature by 5.36% and brake thermal efficiency by 3.16% compared to the brass piston, but also decreased volumetric efficiency more than the other pistons. Overall, the ceramic coatings and brass pistons improved combustion and reduced emissions.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
This document summarizes a study on developing a full mould casting process using polystyrene foam as a pattern. A polystyrene cutting machine was fabricated to cut foam into patterns. An aluminum-silicon alloy was used for casting. Modification was done to improve mechanical properties. Tests found that the casting process produced parts with good shape, mechanical properties, and surface finish using the polystyrene foam pattern and modifier. The full mould casting process allows for complex shapes without draft or flash at lower cost, energy use, and waste compared to other casting methods.
IRJET- Fabrication and Characterization of Hybrid Aluminium Metal Matrix Comp...IRJET Journal
This document describes the fabrication and characterization of a hybrid aluminum metal matrix composite. The composite was created using AA6063 aluminum alloy reinforced with silicon carbide, magnesium, and fly ash particles using stir casting. The goal was to improve the wear rate, tensile strength, compressive strength, and hardness of the composite compared to the unreinforced alloy. Tests were conducted on the composite to evaluate these properties, including ultimate tensile strength testing, wear testing, compressive strength testing, hardness testing, and microstructure analysis. Taguchi's design of experiments method was used to determine the optimum processing parameters to minimize wear rate. The composite showed improved properties over the aluminum alloy alone.
The document describes a project to analyze the effects of applying thermal barrier coatings to diesel locomotive engines. The objectives are to increase power output and efficiency while reducing fuel consumption, emissions, and wear on engine components. The project involves studying engine components, applying thermal barrier coatings, analyzing coatings using simulation software, and reporting on design considerations and results. Thermal barrier coatings aim to insulate components and allow higher operating temperatures to improve performance and lifespan.
IRJET- High Effect of 22Cr10AlY Coating Thickness on Air Hot Corrosion of...IRJET Journal
This document investigates the effect of coating thickness on the oxidation and hot corrosion behavior of nickel-based alloys exposed to air at 850°C and 900°C under cyclic conditions. Nickel-based alloy samples were coated with 22Cr10AlY coatings of thicknesses 50 microns and 100 microns using detonation gun coating. The samples were then subjected to cyclic oxidation testing involving heating for 5 hours at 850°C and 900°C followed by 20 minutes cooling for 10 cycles. Weight change measurements were made to determine the kinetics of oxidation and hot corrosion. Scanning electron microscopy was used to analyze the corroded products. It was observed that the coated nickel alloy with 100 micron coating showed better resistance to oxidation
Thermal Barrier Coating For Gas Turbine EnginesNelsonkandulna
This presentation describes the thermal barrier coating process, its anatomy, types, material selection, failure, and characterization. Thermal barrier coatings (TBCs) were introduced to protect the external surface of gas turbine engine components from thermal resistance and thereby decrease the temperature of the metal surfaces. Yttria stabilized zirconia (YSZ) is one of the most popular and widely used TBC materials as it provides the best performance in high-temperature zones such as diesel engines and gas turbines. The columnar microstructure of YSZ coating provides excellent strain tolerance and adhesion to the coating. Gas turbines are used to power aircraft, trains, ships, electrical generators, pumps, gas compressors, and tanks.
Abstract: The Hot corrosion is the main and severe problem which can be controlled by thermal spray coatings. The various Corrosion control measures include Surface Heat Treatment, Engineering Paints, Vitreous Enamelling, Cladding, Powder coatings, Zinc coatings, Tin Plate, Electroplating, Cadmium Plating, Anodising (Anodizing), Thermal Spray Coatings., Plasma Nitriding/Carburising/Boronising., Pack Cementation, Ion Implantation, Ceramic and Cermet materials., Chemical Vapour Deposition, Physical Vapour Deposition. The demand for protective coatings has increased recently for almost all types of super alloys with improved strength, since high-temperature corrosion problems become much more significant for these alloys with increasing operating temperatures of modern heat engines. The Major areas where coatings have the application are Power generation Industries, Ceramics Industries, Chemical Industries, Iron & steel Industries and Mining Industries etc. Open or closed porosity in thermal spray coatings can originate from several different factors: partially or totally unmolten
particles, inadequate flow or fragmentation of the molten particle at impact, shadowing effects due to lower than the optimal spray angle, and entrapped gas. The interconnected (open) porosity allows the corrosive media to reach the coating-substrate interface, which eventually leads to delamination of the coatings. Although the development of the modern thermal spray
processes has decreased coating porosities, the transport of corrosive species to the substrate can still only be prevented by coating post treatment. Therefore it’s of actual significance to develop an effective method to post treat the thermal spray coatings to enhance their life in corrosive environment. In this paper author has reviewed the significance of heat treatment in thermal spray coatings for improving their properties and has made an attempt to explore the potential of heat treatment
process in thermal spray coatings.
IRJET- Analysis of Shell and Tube Heat Exchanger MaterialsIRJET Journal
This document analyzes materials used for shell and tube heat exchangers. It discusses ceramic and metallic materials like copper alloys and stainless steel. Ceramic materials offer advantages like high temperature resistance, corrosion resistance, and thermal conductivity. However, ceramics also have higher costs. Key factors in selecting heat exchanger materials include maximum operating temperatures, corrosion resistance, mechanical strength, and thermal efficiency. The document concludes that while ceramics increase heat transfer performance, stainless steel remains the most cost-effective conventional material. Material selection requires considering all relevant factors to provide long service life.
Thermal Barrier Coating on IC Engine Piston to Enhance Better Utilization of ...IRJET Journal
The document discusses applying thermal barrier coatings to internal combustion engine pistons to improve engine efficiency. It first provides background on how internal combustion engines work and the purpose of pistons. It then discusses how thermal barrier coatings can insulate engine components and reduce heat transfer, leading to improved heat efficiency and reduced fuel consumption. The document goes on to describe modeling and analysis conducted to design a piston coated with yttria stabilized zirconia thermal barrier material for a 150cc motorcycle engine. Key parameters of the coated piston are presented. In summary, thermal barrier coatings are analyzed as a method to insulate pistons and increase internal combustion engine efficiency by reducing heat losses.
Effect of thermal barrier coating for the improvement of si engine performanc...eSAT Journals
Abstract As per the second law of thermodynamics the efficiency of the engine depends upon the extraction of work against the heat supplied. Minimisation of heat rejection leads to increase the work. Heat rejection takes place through the engine piston, valves and cylinder heads to the surroundings. The aim of the study is to minimise this heat rejection to the surroundings. Heat transfer through the engine parts is minimised by applying the thermal barrier coating materials on the top surface of the engine piston, cylinder heads and valves. In this study an attempt is made to reduce the intensity of thermal and structural stresses by using a layer of the ceramic material, like Yttria stabilized zirconia (YSZ) which has low thermal conductivity, high thermal resistance, chemical inertness, high resistance to erosion, corrosion and high strength was selected as a coating material for engine component. This study present the effect of coating on the piston and the performance of modified four stroke petrol engine and the emission characteristics of the exhaust gas. Key words: Yttrium – zirconium coating, Low heat rejection, Thermal barrier coatings, Engine performance and Emission characteristics
The desired to reach higher efficiencies, lower specific fuel consumption and reduced emission in modern engines has becomes the primary focus of engine researches and manufactures over the past three decades. Ceramic coating is a solution to such problem as they provide good thermal barrier properties for designers. In the design of adiabatic engines, reducing in cylinder heat rejection requires very special thermal barrier coatings on the engine combustion chamber. Partial Thermal barrier coatings (TBC) on the top surface of the piston is considered as a solution for reduction of unburned Hydrocarbon (HC) emission produce by incomplete combustion with respect to crevice volume when engines start. The TBC on the top piston surface decreases the thermal conductivity and increases the unburned charged oxidation, so that the metallic substrates will be exposed to lower peak temperature thereby reducing the thermal stress in engines components. Also thermal barrier coatings on other elements of combustion chamber of internal combustion engine offer advantages including fuel efficiency, multi fuel capacity and high power density. Therefore, thermal barrier coating (TBC) technology is successfully applied to the internal combustion engines, in particular to the combustion chamber.
The document discusses refractories used in steel ladle linings. It describes the key functions of steel ladles in transferring molten steel. Different zones in ladle linings require different refractory materials due to varying temperatures and conditions. Magnesia, dolomite, zircon, carbon and spinel refractories are highlighted as important materials used in slag lines, sidewalls, and bottoms of ladles. Magnesia carbon bricks are well-suited for slag zones due to their thermal properties and corrosion resistance. Monolithic castables based on alumina spinel composites are used in ladle bottoms for their strength, thermal shock resistance and corrosion performance.
COMPARATIVE EMISSION ANALYSIS OF CNG AND OCTANE IN RETROFITTED CAR ENGINESIAEME Publication
Aluminium (Al) reinforced with Titanium Nitride (TiN) Metal Matrix composites find its application for elevated temperature operating conditions. 5, 10 and 15 weight percentage of TiN particles was added to aluminium to prepare the composite through powder metallurgy technique. The mixed powder was compacted at two compacting pressure of 250 MPa and 300 MPa to produce the specimens having h/d ratio in the range of 1.1 to 1.2. The specimens were sintered in nitrogen atmosphere at two different sintering temperatures of 4000C and 5000C with sintering time of 4 hours for each. Physical properties namely, green density, sintered density and mechanical properties such as hardness, compression strength and surface roughness were studied.
Thermal barrier coatings (TBCs) were introduced in the late 1980s to allow gas turbine engine components to operate at temperatures above the melting points of the underlying superalloy materials. TBCs lower the metal surface temperature and protect against oxidation and hot corrosion. Early TBCs were enamels, while modern TBCs use a layered structure with a ceramic top coat, bond coat, and superalloy substrate. New fabrication methods have been developed to improve TBC performance and efficiency, including thick yttria-stabilized-zirconia top coats deposited using electrophoretic deposition and platinum-diffused single gamma prime phase bond coats.
Thermal Barrier Coatings For The Improvement of Spark Ignition EngineBishnu Sarkar
1) The document discusses applying a thermal barrier coating (TBC) to components of a spark ignition engine like the piston and cylinder head to improve engine performance and efficiency.
2) The coating material selected was yttria stabilized zirconia (YSZ) which has low thermal conductivity, high thermal resistance, and is chemically inert, to minimize heat rejection from the engine to the surroundings.
3) Applying the YSZ coating leads to benefits like higher power density, fuel efficiency, and ability to use multiple fuels for the engine due to an increased combustion chamber temperature from reduced heat loss.
Design and Fabrication of Crucible Furnaces by using Black Smithy SetupDr. Amarjeet Singh
The main aim was, to design Pit Furnace from the
setup of black smithy. As the Smithy setup was not in use so it
is converted into Pit Furnace setup. The purpose of using Pit
Furnace is to melt nonferrous material. The Nonferrous
materials such as Aluminum, Aluminum alloy, Copper, Brass,
etc. The Aluminum has less melting point (680ᵒ C, 1218ᵒF) and
cheaper than other. The thermal efficiency of furnace is
13.72% which is obtained by melting 2 kg of Aluminum for 75
minutes. Normally thermal of pit furnace is between 4-19%.
The blower is used to supply the air into the furnace chamber
to burn the coal. For melting the Aluminum, Crucible should
sustain higher temperature so Graphite Crucible is used. This
Crucible has thinner wall and have more refractory
properties.
This document discusses thermal barrier coatings (TBCs) used to protect metallic parts from high temperatures. It provides information on the structure and processing of TBCs as well as their failure mechanisms. TBCs have a multi-layer structure consisting of a metallic bond coat and ceramic top coat to provide thermal insulation. Failure typically occurs through spallation of the top coat due to stresses from the growth of an oxide layer at the interface. The document reviews approaches to improve TBC performance and durability through heat treatments of the bond coat and developing gradient coatings.
Powder metallurgy is a metalworking process that involves pressing and sintering metal powders to form finished parts. Key steps include mixing metal powders with lubricants, compacting the powder mixture in a die under pressure to form a green compact, and sintering the compact at high temperatures to fuse powder particles together without melting. Powder metallurgy allows for net-shape production of complex parts from a variety of materials at high production rates and relatively low cost compared to other manufacturing methods.
Thermal barrier coatings were originally developed for aircraft engines in 1940 but are now being tested for use in diesel engines. These coatings can reduce the metal temperature of engine components by up to 170 degrees Celsius. There are two main coating techniques - surface preparation and thermal spraying. Thermal spraying techniques like wire flame spraying and plasma arc spraying are used to melt and spray coating materials like metallic wires or powder onto engine components. The use of ceramic thermal barrier coatings on a single cylinder diesel engine resulted in increased brake thermal efficiency from 16% to 20.4%.
MICROWAVE SINTERING OF REFRACTORY METALS Chuchu Beera
The document discusses microwave sintering of refractory metals like tungsten, molybdenum, and rhenium. It explains that microwave sintering allows these metals to reach high densities at lower temperatures and shorter times compared to conventional sintering. Specifically, it achieves near theoretical densities of 98% for tungsten, molybdenum, and rhenium in just a few minutes of microwave sintering at temperatures as low as 1400-2000°C, whereas conventional sintering requires hours at temperatures over 2000°C. The document also notes that microwave sintering results in finer grain sizes and improved mechanical properties for these refractory metals.
The document presents a seminar on thermal barrier coatings (TBC). TBCs provide thermal insulation on metallic parts through a multi-layer structure, allowing parts to operate at higher temperatures. The structure includes a ceramic top coat for insulation over a bond coat that prevents oxidation, on a superalloy substrate. Common deposition methods are electron beam physical vapor deposition and air plasma spray. TBCs allow gas turbine blades and engines to run at higher temperatures, increasing efficiency while protecting the substrate from failure modes like thermal fatigue. However, thermal cycling can still cause TBCs to spall off over time due to thermal mismatch.
The presentation is related to the plasma spraying that covers the principle of working, setup, advantages - Limitations along with the factors affecting the overall process.
Hot corrosion performance of HVOF sprayed coatingsHARKULVINDER84
Abstract- Hot corrosion is a serious problem in boilers,
gas turbines, internal combustion engines, and
industrial waste incinerators. It consumes the
materials at an unpredictably rapid rate. The use of
protective coatings has been an answer to remedy the
lack of high temperature surface stability of metals
and alloys in harsh environments. Coating can be
deposited by electric arc spray, physical vapour
deposition, detonation spraying, flame spray, vacuum
plasma spray, low pressure plasma spray, high velocity
oxy fuel by sputtering or by evaporation. High-velocity
oxy-fuel (HVOF) spraying is a new and rapidly
developing technology in combating high-temperature
corrosion. HVOF coatings have very low porosity, high
hardness, high abrasive resistance, good wear
resistance with a strong ability to resist high temperature
corrosion resistance. This study is done
with the aim of putting together the performance
capabilities and applications of HVOF process.
Este documento trata sobre diferentes tipos de anemia y angina de pecho. Describe la anemia aplásica como una enfermedad grave de la médula ósea que afecta a los glóbulos rojos, blancos y plaquetas. También explica la anemia en el embarazo, la cual ocurre debido a alteraciones digestivas y el consumo de nutrientes por el feto. Finalmente, define la angina de pecho como un síndrome causado por falta de oxígeno al corazón, con síntomas como dolor en el pecho que puede al
This document describes a wireless SCADA system for industrial automation using M2M communication. The system uses various sensors to measure parameters like temperature, humidity, light, and LPG. An ADC converts the analog sensor readings to digital values, which a microcontroller processes and sends via GSM to a remote computer. The system allows monitoring and controlling industrial processes from anywhere via the internet. It aims to provide low-cost, low-power automation without distance barriers compared to traditional SCADAs. Future work may add switches/routers for networking and wireless cameras to improve security and monitoring capabilities.
Abstract: The Hot corrosion is the main and severe problem which can be controlled by thermal spray coatings. The various Corrosion control measures include Surface Heat Treatment, Engineering Paints, Vitreous Enamelling, Cladding, Powder coatings, Zinc coatings, Tin Plate, Electroplating, Cadmium Plating, Anodising (Anodizing), Thermal Spray Coatings., Plasma Nitriding/Carburising/Boronising., Pack Cementation, Ion Implantation, Ceramic and Cermet materials., Chemical Vapour Deposition, Physical Vapour Deposition. The demand for protective coatings has increased recently for almost all types of super alloys with improved strength, since high-temperature corrosion problems become much more significant for these alloys with increasing operating temperatures of modern heat engines. The Major areas where coatings have the application are Power generation Industries, Ceramics Industries, Chemical Industries, Iron & steel Industries and Mining Industries etc. Open or closed porosity in thermal spray coatings can originate from several different factors: partially or totally unmolten
particles, inadequate flow or fragmentation of the molten particle at impact, shadowing effects due to lower than the optimal spray angle, and entrapped gas. The interconnected (open) porosity allows the corrosive media to reach the coating-substrate interface, which eventually leads to delamination of the coatings. Although the development of the modern thermal spray
processes has decreased coating porosities, the transport of corrosive species to the substrate can still only be prevented by coating post treatment. Therefore it’s of actual significance to develop an effective method to post treat the thermal spray coatings to enhance their life in corrosive environment. In this paper author has reviewed the significance of heat treatment in thermal spray coatings for improving their properties and has made an attempt to explore the potential of heat treatment
process in thermal spray coatings.
IRJET- Analysis of Shell and Tube Heat Exchanger MaterialsIRJET Journal
This document analyzes materials used for shell and tube heat exchangers. It discusses ceramic and metallic materials like copper alloys and stainless steel. Ceramic materials offer advantages like high temperature resistance, corrosion resistance, and thermal conductivity. However, ceramics also have higher costs. Key factors in selecting heat exchanger materials include maximum operating temperatures, corrosion resistance, mechanical strength, and thermal efficiency. The document concludes that while ceramics increase heat transfer performance, stainless steel remains the most cost-effective conventional material. Material selection requires considering all relevant factors to provide long service life.
Thermal Barrier Coating on IC Engine Piston to Enhance Better Utilization of ...IRJET Journal
The document discusses applying thermal barrier coatings to internal combustion engine pistons to improve engine efficiency. It first provides background on how internal combustion engines work and the purpose of pistons. It then discusses how thermal barrier coatings can insulate engine components and reduce heat transfer, leading to improved heat efficiency and reduced fuel consumption. The document goes on to describe modeling and analysis conducted to design a piston coated with yttria stabilized zirconia thermal barrier material for a 150cc motorcycle engine. Key parameters of the coated piston are presented. In summary, thermal barrier coatings are analyzed as a method to insulate pistons and increase internal combustion engine efficiency by reducing heat losses.
Effect of thermal barrier coating for the improvement of si engine performanc...eSAT Journals
Abstract As per the second law of thermodynamics the efficiency of the engine depends upon the extraction of work against the heat supplied. Minimisation of heat rejection leads to increase the work. Heat rejection takes place through the engine piston, valves and cylinder heads to the surroundings. The aim of the study is to minimise this heat rejection to the surroundings. Heat transfer through the engine parts is minimised by applying the thermal barrier coating materials on the top surface of the engine piston, cylinder heads and valves. In this study an attempt is made to reduce the intensity of thermal and structural stresses by using a layer of the ceramic material, like Yttria stabilized zirconia (YSZ) which has low thermal conductivity, high thermal resistance, chemical inertness, high resistance to erosion, corrosion and high strength was selected as a coating material for engine component. This study present the effect of coating on the piston and the performance of modified four stroke petrol engine and the emission characteristics of the exhaust gas. Key words: Yttrium – zirconium coating, Low heat rejection, Thermal barrier coatings, Engine performance and Emission characteristics
The desired to reach higher efficiencies, lower specific fuel consumption and reduced emission in modern engines has becomes the primary focus of engine researches and manufactures over the past three decades. Ceramic coating is a solution to such problem as they provide good thermal barrier properties for designers. In the design of adiabatic engines, reducing in cylinder heat rejection requires very special thermal barrier coatings on the engine combustion chamber. Partial Thermal barrier coatings (TBC) on the top surface of the piston is considered as a solution for reduction of unburned Hydrocarbon (HC) emission produce by incomplete combustion with respect to crevice volume when engines start. The TBC on the top piston surface decreases the thermal conductivity and increases the unburned charged oxidation, so that the metallic substrates will be exposed to lower peak temperature thereby reducing the thermal stress in engines components. Also thermal barrier coatings on other elements of combustion chamber of internal combustion engine offer advantages including fuel efficiency, multi fuel capacity and high power density. Therefore, thermal barrier coating (TBC) technology is successfully applied to the internal combustion engines, in particular to the combustion chamber.
The document discusses refractories used in steel ladle linings. It describes the key functions of steel ladles in transferring molten steel. Different zones in ladle linings require different refractory materials due to varying temperatures and conditions. Magnesia, dolomite, zircon, carbon and spinel refractories are highlighted as important materials used in slag lines, sidewalls, and bottoms of ladles. Magnesia carbon bricks are well-suited for slag zones due to their thermal properties and corrosion resistance. Monolithic castables based on alumina spinel composites are used in ladle bottoms for their strength, thermal shock resistance and corrosion performance.
COMPARATIVE EMISSION ANALYSIS OF CNG AND OCTANE IN RETROFITTED CAR ENGINESIAEME Publication
Aluminium (Al) reinforced with Titanium Nitride (TiN) Metal Matrix composites find its application for elevated temperature operating conditions. 5, 10 and 15 weight percentage of TiN particles was added to aluminium to prepare the composite through powder metallurgy technique. The mixed powder was compacted at two compacting pressure of 250 MPa and 300 MPa to produce the specimens having h/d ratio in the range of 1.1 to 1.2. The specimens were sintered in nitrogen atmosphere at two different sintering temperatures of 4000C and 5000C with sintering time of 4 hours for each. Physical properties namely, green density, sintered density and mechanical properties such as hardness, compression strength and surface roughness were studied.
Thermal barrier coatings (TBCs) were introduced in the late 1980s to allow gas turbine engine components to operate at temperatures above the melting points of the underlying superalloy materials. TBCs lower the metal surface temperature and protect against oxidation and hot corrosion. Early TBCs were enamels, while modern TBCs use a layered structure with a ceramic top coat, bond coat, and superalloy substrate. New fabrication methods have been developed to improve TBC performance and efficiency, including thick yttria-stabilized-zirconia top coats deposited using electrophoretic deposition and platinum-diffused single gamma prime phase bond coats.
Thermal Barrier Coatings For The Improvement of Spark Ignition EngineBishnu Sarkar
1) The document discusses applying a thermal barrier coating (TBC) to components of a spark ignition engine like the piston and cylinder head to improve engine performance and efficiency.
2) The coating material selected was yttria stabilized zirconia (YSZ) which has low thermal conductivity, high thermal resistance, and is chemically inert, to minimize heat rejection from the engine to the surroundings.
3) Applying the YSZ coating leads to benefits like higher power density, fuel efficiency, and ability to use multiple fuels for the engine due to an increased combustion chamber temperature from reduced heat loss.
Design and Fabrication of Crucible Furnaces by using Black Smithy SetupDr. Amarjeet Singh
The main aim was, to design Pit Furnace from the
setup of black smithy. As the Smithy setup was not in use so it
is converted into Pit Furnace setup. The purpose of using Pit
Furnace is to melt nonferrous material. The Nonferrous
materials such as Aluminum, Aluminum alloy, Copper, Brass,
etc. The Aluminum has less melting point (680ᵒ C, 1218ᵒF) and
cheaper than other. The thermal efficiency of furnace is
13.72% which is obtained by melting 2 kg of Aluminum for 75
minutes. Normally thermal of pit furnace is between 4-19%.
The blower is used to supply the air into the furnace chamber
to burn the coal. For melting the Aluminum, Crucible should
sustain higher temperature so Graphite Crucible is used. This
Crucible has thinner wall and have more refractory
properties.
This document discusses thermal barrier coatings (TBCs) used to protect metallic parts from high temperatures. It provides information on the structure and processing of TBCs as well as their failure mechanisms. TBCs have a multi-layer structure consisting of a metallic bond coat and ceramic top coat to provide thermal insulation. Failure typically occurs through spallation of the top coat due to stresses from the growth of an oxide layer at the interface. The document reviews approaches to improve TBC performance and durability through heat treatments of the bond coat and developing gradient coatings.
Powder metallurgy is a metalworking process that involves pressing and sintering metal powders to form finished parts. Key steps include mixing metal powders with lubricants, compacting the powder mixture in a die under pressure to form a green compact, and sintering the compact at high temperatures to fuse powder particles together without melting. Powder metallurgy allows for net-shape production of complex parts from a variety of materials at high production rates and relatively low cost compared to other manufacturing methods.
Thermal barrier coatings were originally developed for aircraft engines in 1940 but are now being tested for use in diesel engines. These coatings can reduce the metal temperature of engine components by up to 170 degrees Celsius. There are two main coating techniques - surface preparation and thermal spraying. Thermal spraying techniques like wire flame spraying and plasma arc spraying are used to melt and spray coating materials like metallic wires or powder onto engine components. The use of ceramic thermal barrier coatings on a single cylinder diesel engine resulted in increased brake thermal efficiency from 16% to 20.4%.
MICROWAVE SINTERING OF REFRACTORY METALS Chuchu Beera
The document discusses microwave sintering of refractory metals like tungsten, molybdenum, and rhenium. It explains that microwave sintering allows these metals to reach high densities at lower temperatures and shorter times compared to conventional sintering. Specifically, it achieves near theoretical densities of 98% for tungsten, molybdenum, and rhenium in just a few minutes of microwave sintering at temperatures as low as 1400-2000°C, whereas conventional sintering requires hours at temperatures over 2000°C. The document also notes that microwave sintering results in finer grain sizes and improved mechanical properties for these refractory metals.
The document presents a seminar on thermal barrier coatings (TBC). TBCs provide thermal insulation on metallic parts through a multi-layer structure, allowing parts to operate at higher temperatures. The structure includes a ceramic top coat for insulation over a bond coat that prevents oxidation, on a superalloy substrate. Common deposition methods are electron beam physical vapor deposition and air plasma spray. TBCs allow gas turbine blades and engines to run at higher temperatures, increasing efficiency while protecting the substrate from failure modes like thermal fatigue. However, thermal cycling can still cause TBCs to spall off over time due to thermal mismatch.
The presentation is related to the plasma spraying that covers the principle of working, setup, advantages - Limitations along with the factors affecting the overall process.
Hot corrosion performance of HVOF sprayed coatingsHARKULVINDER84
Abstract- Hot corrosion is a serious problem in boilers,
gas turbines, internal combustion engines, and
industrial waste incinerators. It consumes the
materials at an unpredictably rapid rate. The use of
protective coatings has been an answer to remedy the
lack of high temperature surface stability of metals
and alloys in harsh environments. Coating can be
deposited by electric arc spray, physical vapour
deposition, detonation spraying, flame spray, vacuum
plasma spray, low pressure plasma spray, high velocity
oxy fuel by sputtering or by evaporation. High-velocity
oxy-fuel (HVOF) spraying is a new and rapidly
developing technology in combating high-temperature
corrosion. HVOF coatings have very low porosity, high
hardness, high abrasive resistance, good wear
resistance with a strong ability to resist high temperature
corrosion resistance. This study is done
with the aim of putting together the performance
capabilities and applications of HVOF process.
Este documento trata sobre diferentes tipos de anemia y angina de pecho. Describe la anemia aplásica como una enfermedad grave de la médula ósea que afecta a los glóbulos rojos, blancos y plaquetas. También explica la anemia en el embarazo, la cual ocurre debido a alteraciones digestivas y el consumo de nutrientes por el feto. Finalmente, define la angina de pecho como un síndrome causado por falta de oxígeno al corazón, con síntomas como dolor en el pecho que puede al
This document describes a wireless SCADA system for industrial automation using M2M communication. The system uses various sensors to measure parameters like temperature, humidity, light, and LPG. An ADC converts the analog sensor readings to digital values, which a microcontroller processes and sends via GSM to a remote computer. The system allows monitoring and controlling industrial processes from anywhere via the internet. It aims to provide low-cost, low-power automation without distance barriers compared to traditional SCADAs. Future work may add switches/routers for networking and wireless cameras to improve security and monitoring capabilities.
The document describes a study comparing DNA fingerprinting techniques of Amplified Ribosomal DNA Restriction Analysis (ARDRA) and rep-PCR fingerprinting using BOX-A1R primer for the identification of Bacillus species. A collection of 171 soil bacterial isolates was tested with Bacillus group-specific PCR primers. Isolates that tested positive were further analyzed by ARDRA and rep-PCR fingerprinting and compared to standard Bacillus strains. Cluster analysis of the fingerprinting patterns revealed grouping of isolates with B. thuringiensis, B. megaterium, B. pumilus and B. subtilis. Sequencing of some isolates showed identification of Bacillus at the species level was
This document summarizes research on human motion tracking techniques using skeleton models. It discusses how model-based approaches use a predefined human skeleton model to represent joints and segments. Video-based approaches can infer physical attributes and daily actions without sensors. The document reviews several papers on reconstructing 3D human pose from video, using reduced joint sets and shape models to filter noise and track landmarks, and developing multi-view pose tracking using generative sampling and physical constraints. It also discusses challenges like high degrees of freedom and self-occlusion, and the need for efficient algorithms to enable real-time 3D full-body motion tracking from multiple cameras.
This document proposes and evaluates methods for fusing 3D ear and face biometrics at the score level and feature level for personal authentication. Local 3D features are extracted from ear and face data and fused using root mean square distance matching at the feature level. At the score level, matching scores from ear and face modalities are fused using weighted sum rule techniques. Experiments on a database of 990 ear and face images from 60 individuals show that the multimodal biometrics systems using feature level or score level fusion techniques have lower equal error rates compared to unimodal ear or face systems alone, demonstrating improved performance from fusing the biometric modalities.
This document describes a Multilevel Relationship Algorithm (MRA) for improving association rule mining. MRA works in three stages: 1) It uses an Apriori algorithm to find level 1 associations between items within individual shops. 2) It uses the level 1 associations to find frequent itemsets across shops. 3) It uses Bayesian probability to determine dependencies between items across shops and generate learning rules. The algorithm aims to discover relationships between sales data from different shops to gain insights for business decisions.
This document summarizes a research paper that surveyed detection and prevention mechanisms for flooding attacks in mobile ad hoc networks (MANETs). It began with an abstract that described how MANETs are increasingly being used but also face security threats like flooding attacks. It then provided definitions and characteristics of MANETs and described two common routing protocols: AODV and OLSR. The paper discussed flooding attacks and different detection and prevention schemes that have been proposed. It concluded with a survey of these mechanisms to detect and mitigate flooding attacks in MANETs.
This document discusses the relationship between information and communication technology (ICT) and e-learning, with a focus on how data mining can be used in the context of e-learning. It first provides background on e-learning and how ICT has enhanced e-learning through technologies like web 2.0. It then discusses how educational data mining uses data collected by e-learning systems and tools to gain insights about students, learning, and how to improve practices. Specific techniques like analyzing keystroke data and data at different levels can provide valuable information. The document concludes that data mining techniques applied by education experts can help address open challenges in e-learning systems and help transform education in India.
This document proposes an Android application that uses Huffman encoding to compress SMS messages. It summarizes that Huffman coding assigns shorter code words to more frequently used symbols, allowing SMS text to be compressed. The application requires installation on both the sender and receiver's phones to decompress messages. Testing showed the technique achieved up to 89% compression, reducing the size of example SMS texts. The summary provides an overview of the key points about using Huffman coding for SMS compression and the proposed mobile application.
This document proposes a hybrid optimization algorithm using ant colony optimization and particle swarm optimization to solve the multiobjective multicast routing problem in wireless sensor networks. The goal is to optimize two objectives simultaneously - end-to-end delay and total transmitted power. ACO and PSO are combined to find Pareto-optimal solutions efficiently. Simulation results show the algorithm can find near-optimal solutions for minimizing delay and power consumption when routing data from a source to multiple destinations in wireless sensor networks.
This document describes a microcontroller-based gas flow alert system for an industrial furnace. The system monitors the furnace's gas flow mode (manual vs automatic) and uses a GSM modem to send alert messages if the mode is not changed on schedule. This helps reduce wasted nitrogen gas flow and lower production costs by ensuring the optimal gas flow level is maintained based on whether items are actively being loaded into the furnace. The system was designed and assembled with a microcontroller board connected to a GSM modem. It provides alerts if the operator fails to change the furnace mode between shifts, allowing nitrogen usage and costs to be reduced by an estimated Rs. 10,407.93 per month.
El documento presenta información sobre los eclipses lunares y solares. Explica que un eclipse ocurre cuando un cuerpo celeste bloquea la luz de otro cuerpo celeste. Un eclipse lunar se produce cuando la Tierra está entre la Luna y el Sol y la sombra de la Tierra oscurece la Luna. Un eclipse solar ocurre cuando la Luna está entre el Sol y la Tierra y proyecta su sombra sobre la superficie terrestre.
This document describes the fabrication of tin oxide (SnO2) thin films using the spray pyrolysis technique. Spray pyrolysis involves spraying a metal salt solution onto a heated substrate where the droplets undergo thermal decomposition to form an oxide thin film. The key deposition parameters that influence the thin film properties are substrate temperature, aerosol transport properties, and precursor decomposition behavior. Higher substrate temperatures result in rougher, more porous films with improved crystallinity and electrical properties. Proper control of deposition parameters allows for the fabrication of thin films with tailored optical and electrical characteristics using the low-cost spray pyrolysis method.
This document summarizes the synthesis and characterization of thin films of pure TiO2 and Sr-doped TiO2 prepared by spin coating technique. Transparent thin films were prepared on glass substrates and annealed at different temperatures from 3000C to 6000C. Structural analysis using GIXRD and Raman spectroscopy confirmed the anatase phase of TiO2. AFM showed a homogeneous globular surface morphology. UV-Vis analysis demonstrated that the optical band gap increased with higher annealing temperatures. Photoluminescence study showed variation in emission peaks for different annealing temperatures and Sr concentrations. Electrical, gas sensing, wettability and self-cleaning properties were also investigated.
This document describes an experimental study of heat transfer in a rectangular duct with and without internal V-shaped ribs. Experiments were conducted with air flow in turbulent regime (Reynolds numbers 3000-18000) in smooth duct and ducts with continuous or discrete internal V-shaped ribs. Temperature and pressure measurements were taken to determine heat transfer coefficients and friction factors for different configurations. Results showed that continuous ribs enhanced heat transfer more than discrete ribs, but also increased pressure drop more substantially. Heat transfer enhancement was dependent on rib geometry and position.
This document describes a student attendance recording system using face recognition and GSM technology. The system uses a webcam to capture images of students' faces and matches them to images stored in a database using MATLAB. If a match is found, a text message is sent using a GSM board to notify that the student has attended class. The system aims to automate attendance tracking and address issues with conventional paper-based systems. It provides accurate attendance recording and real-time notification without requiring students to manually sign attendance sheets or carry RFID cards. The results found nearly 100% accurate recognition and authentication of student faces compared to the stored images in testing.
This document summarizes the results of a finite element analysis of vibration effects on an internal combustion engine exhaust valve. The analysis sought to determine the natural frequency of the valve at which resonance might occur. A 3D CAD model of the valve was created and meshed before applying boundary conditions and material properties in ANSYS finite element software. Vibration analysis identified 5 modes of vibration with increasing frequencies up to a maximum of 1511.3 Hz, deemed the natural frequency. While deformations were largest at intermediate frequencies, the analysis concluded that vibrations near the natural frequency could damage the valve. Therefore, reducing deformation through constraints and maintaining operation below the natural frequency were recommended.
The document discusses gesture-based computing as an alternative to mouse input for human-computer interaction. It proposes a novel approach for implementing a real-time gesture recognition system capable of understanding commands based on analyzing the principal contour and fingertips of hand gestures. Vision-based gesture recognition techniques are discussed that do not require additional devices for users to interact with computers through natural hand motions.
The document describes a technique for error detection and correction in data transmission using multidirectional parity codes and Hamming codes. It proposes applying multidirectional parity codes to generate check bits for data, encoding the check bits using Hamming codes, and transmitting the data and check bits. At the receiver, Hamming decoding detects and corrects errors in check bits, and multidirectional parity decoding detects and corrects errors in data. Simulation results show the technique can detect and correct up to four bit errors, an improvement over other codes. It provides reliable error correction with reasonably low overhead.
Overview on Thermal Barrier Coatings Application and DevelopmentIJRES Journal
This paper mainly summary the application and development of thermal barrier coatings (TBC) in last decades. TBCs have been widely used in automotive, gas turbine, solid oxide fuel cell and other fields. It can protect substrate materials from high temperature oxidation and corrosion meanwhile increasing lifetime of parts and improving the work efficiency. At last, the development trend of TBC was referred on the TBCs materials and structures.
This document discusses the design and static thermal analysis of a piston using thermal barrier coating materials. It aims to increase engine performance by applying a thermal barrier coating to the piston crown. The project considers coating a 150cc engine piston crown with 0.4mm of two different thermal barrier coating materials and using finite element analysis to calculate stresses, strains, temperatures and heat flux. The goal is to determine which material is most suitable for reducing heat transfer and increasing engine efficiency.
This document summarizes a seminar report on thermal barrier coatings. It discusses that thermal barrier coatings consist of a metallic bond coat, thermally grown oxide layer, and ceramic top coat, most commonly yttria-stabilized zirconia. It reviews common deposition methods for thermal barrier coatings like air plasma spray, electron beam physical vapor deposition, and electrostatic spray assisted vapor deposition. The document concludes that thermal barrier coatings improve engine performance by allowing higher operating temperatures and reduce maintenance costs, making them an important technology with applications in industries like aerospace and automotive.
The desired to reach higher efficiencies, lower specific fuel consumption and reduced emission in modern engines has becomes the primary focus of engine researches and manufactures over the past three decades. Ceramic coating is a solution to such problem as they provide good thermal barrier properties for designers. In the design of adiabatic engines, reducing in cylinder heat rejection requires very special thermal barrier coatings on the engine combustion chamber. Partial Thermal barrier coatings (TBC) on the top surface of the piston is considered as a solution for reduction of unburned Hydrocarbon (HC) emission produce by incomplete combustion with respect to crevice volume when engines start. The TBC on the top piston surface decreases the thermal conductivity and increases the unburned charged oxidation, so that the metallic substrates will be exposed to lower peak temperature thereby reducing the thermal stress in engines components. Also thermal barrier coatings on other elements of combustion chamber of internal combustion engine offer advantages including fuel efficiency, multi fuel capacity and high power density. Therefore, thermal barrier coating (TBC) technology is successfully applied to the internal combustion engines, in particular to the combustion chamber.
This seminar presentation discusses thermal barrier coatings (TBCs). TBCs are ceramic oxide coatings applied to metallic parts to insulate them and allow operation at higher temperatures. A TBC system consists of a top ceramic coating, thermally grown oxide layer, bond coat, and superalloy substrate. Common TBC materials use yttria-stabilized zirconia due to its low thermal conductivity. Two deposition methods discussed are electron beam physical vapor deposition and air plasma spray. TBCs can increase efficiency in gas turbine engines and diesel engines by allowing higher operating temperatures. However, thermal cycling can cause TBCs to fail through spalling of the top coating.
Thermal barrier coatings (TBCs) were first applied to gas turbine engine blades in the late 1980s to increase engine efficiency and temperatures. TBCs lower the metal surface temperature of superalloy components, protecting them from oxidation and corrosion allowing for higher operating temperatures. A typical TBC system uses a bond coat that forms a protective thermally grown oxide layer and a ceramic top coat with low thermal conductivity to further insulate the metal underneath. New fabrication methods for thicker, more uniformly porous top coats and diffusion strengthened bond coats have improved TBC performance and efficiency.
Thermal barrier coatings (TBCs) are advanced materials applied to gas turbine and aero-engine parts to insulate components from high operating temperatures. TBCs utilize thermally insulating ceramic materials to create a temperature difference between the underlying alloy and coating surface, allowing components to withstand higher temperatures while reducing thermal fatigue and extending part life. Yttria-stabilized zirconia is commonly used as the TBC material due to its low thermal conductivity, high spallation resistance, and erosion resistance. Researchers are exploring alternative TBC materials like zirconates and garnets to improve properties like sintering resistance and thermal cycling performance.
Development of Thermal Barrier Coating by thermal spraying for high temperatu...NishantKumarMehta
Thermal barrier coatings (TBCs) allow gas turbine engines to operate at higher temperatures, improving efficiency. There are two main methods for depositing TBCs: plasma spraying and electron beam physical vapor deposition. Plasma spraying involves melting and accelerating materials using a plasma jet, resulting in a splatted microstructure, while EBPVD uses an electron beam to evaporate materials into a columnar structure. Common TBC materials include yttria-stabilized zirconia due to its low thermal conductivity. TBCs can fail through oxidation, hot corrosion, or deposition of combustion byproducts on the coating surface.
LAB SCALE PREPARATION AND EVALUATION OF YTTRIA STABILIZED ZIRCONIA THERMAL BA...ijmech
Ceramic based coatings are routinely being engineered to protect metallic components from high
temperature environments in applications like gas turbines and jet engines. However, although a wellresearched
technology, detailed and realistic information on the effects of thermal barrier coatings (TBCs)
in improving the performance of commercial diesel engines is either classified or inconsistent. Additional
information by means of lab scale and analytical evaluation of TBCs prepared from 8%Y2O3-ZrO2 plasma
sprayable powders (prepared in the laboratory by using organic binders), coated onto aluminium
substrates, corroborated by simulation model is one part of this paper. The findings are supplemented by
studying the influence of the TBCs on aluminium pistons in a single cylinder nine horsepower class diesel
engine, thereby carrying out realistic performance of the engine involving parameters such as Power
(Brake, Indicated and Frictional), thermal efficiency, fuel consumption, effects of ceramic insulation on
emission and exhaust temperature and peak cylinder pressure, as the concluding part of the studies.
This document describes the computational thermal analysis of a fused calcia zirconia ceramic coating applied to the piston head of a diesel engine. It begins with an introduction to functionally graded materials and thermal barrier coatings. It then describes the modeling and meshing process in ANSYS for the uncoated and coated piston, including the element types used. The document provides equations and examples related to piston and engine design. It discusses factors that influence the lifetime of thermal barrier coatings and how coatings can improve engine performance. In summary, a ceramic coating is analyzed computationally to reduce heat transfer and thermal stresses in the piston.
The document summarizes an investigation into applying a thermal barrier coating (TBC) of zirconia ceramic onto an internal combustion engine piston using plasma arc spraying. Key findings include:
1) Applying the TBC reduced heat transfer to the cooling jacket and exhaust system, improving mechanical efficiency and decreasing fuel consumption by up to 6%.
2) Emissions of unburned hydrocarbons were reduced due to lower heat rejection, while carbon monoxide emissions did not significantly change.
3) Some potential drawbacks of thicker TBC coatings include higher internal stresses due to larger temperature gradients and increased risk of coating failure over time.
Experimental investigations on the performance and emissoin characteristicsIAEME Publication
1. The document experimentally investigates the performance and emission characteristics of a diesel engine with mullite ceramic coating.
2. Testing found that the mullite thermal barrier coating improved the engine's brake thermal efficiency by up to 5.78% and reduced specific fuel consumption by 5.46% compared to the uncoated engine. Emissions such as smoke and CO were also reduced.
3. The mullite coating provides thermal insulation which increases in-cylinder temperatures and aids combustion, improving performance and reducing some emissions while increasing NOx emissions by around 4%. The coating demonstrates potential as an alternative to conventional yttria stabilized zirconia thermal barrier coatings.
This document discusses selecting heating elements for electrically heated furnaces and kilns. It describes the main classes of heating elements used - metallic, silicon carbide, and molybdenum disilicide. Metallic elements are cheaper but have lower maximum temperatures, while molybdenum disilicide can withstand the highest temperatures. The document provides guidelines for selecting an element based on the maximum furnace temperature and considers other factors like watt loading and element lifespan. Metallic elements require more careful material selection and configuration to optimize performance based on the furnace atmosphere and operating conditions.
Experimental Analysis of YSZ Coating on an IC Engine Pistonresearchinventy
As per the second law of thermodynamics the IC (Internal Combustion) engine efficiency depends upon the extraction of work against the heat supplied. Minimization of heat rejection leads to increase the work. Heat rejection takes place through the engine piston, valves and cylinder heads to the surroundings. The aim of the study is to minimize this heat rejection to the surroundings. Heat transfer through the engine parts can minimize by applying the thermal barrier coating materials on the top surface of the engine piston, cylinder heads and valves. In this study an attempt is made to reduce the intensity of heat rejection by using a layer of the ceramic material, like Yttrium Stabilized Zirconia (YSZ) which has low thermal conductivity, high thermal resistance, chemical inertness, high resistance to erosion, corrosion and high strength was selected as a coating material for engine component. In this paper the experiments were carried out with 0.4mm YSZ coated piston and it is found that it has 1% total fuel consumption, 1.2% specific fuel consumption and 0.7% exhaust gas temperature less than the conventional engine with uncoated piston. It is also seen that 2.6% brake thermal efficiency, 2.14% indicated thermal efficiency and 1.35% mechanical efficiency more than the conventional engine with uncoated piston.
A Review on Coating of Titanium Alloy on Mild Steel using Thermal Spray Techn...IRJET Journal
This document reviews coating titanium alloy on mild steel using thermal spray techniques. It discusses several thermal spray coating processes including electric arc wire spraying, cold spraying, flame spraying, and high velocity oxy-fuel (HVOF) spraying. HVOF spraying is identified as particularly suitable for producing dense, adherent coatings with few oxides due to the high particle velocity and relatively cold flame compared to other thermal spray techniques. The document provides details on the operating principles and benefits of each thermal spray coating process.
This document summarizes a study that analyzed the thermal performance of different material combinations for vehicle roofs using computer simulations. The study aimed to reduce heat transfer through the roof and into the vehicle cabin. Three-layer material combinations of cenosphere-magnesium-cenosphere and cenosphere-nimonic-cenosphere were modeled and tested. The cenosphere-nimonic-cenosphere design showed a slightly larger reduction in inside roof temperature of 20.10°C compared to the cenosphere-magnesium-cenosphere design which reduced temperature by 20.02°C. Both designs showed potential to reduce heat transfer into the vehicle and improve thermal comfort for passengers.
The document discusses technologies for improving gas turbine efficiency through higher operating temperatures. It covers new high-temperature materials like superalloys and ceramics that allow increasing the combustion temperature. It also discusses manufacturing techniques like directional solidification and single crystal growth that enhance material properties. Combined cycle power plants are highlighted as a way to further increase efficiency by capturing waste heat. Challenges of using syngas from gasification as a fuel are also summarized.
REVIEW ON EFFECT OF VARIOUS REINFORCEMENTS ON THE THERMAL PROPERTIES OF LM-25...IAEME Publication
For thermal management in applications like automobiles, aviation, marine etc. we need materials with high thermal conductivity, low coefficient of thermal expansion and at the same time the materials should have high strength, high corrosion resistance and low density. Aluminum alloys are excellent choices as the alloys possess all these properties. In order to improve the properties of the alloys further to make them more suitable for the applications, alloys are reinforced with different materials. This review focuses on influence on thermal properties of LM25 and some common light metal alloys reinforced with different materials, effect of heat and solution treatments on LM25/SiC MMC, effect of aging treatment on thermal fatigue of LM-25 alloy and the most common synthesis technique used
Study of Materials used in Gas Turbine engine and swirler in combustion chamberIJARIIE JOURNAL
This document discusses materials used in gas turbine engines, with a focus on the swirler in the combustion chamber. It first introduces the students who authored the paper and provides an abstract that overviews studying materials for gas turbine components to enhance performance, reliability and durability. The main body then discusses materials used for turbine blades and wheels, focusing on titanium and nickel-based alloys that can withstand high temperatures and stresses. It also examines protective coatings and the role of swirlers in reducing emissions.
Reduction of cold start emissions in automotive catalytic converter using the...Asheesh Padiyar
Catalytic converters are used to convert harmful exhaust gases like CO, NOx and unburnt hydrocarbons released by
internal combustion engine of automobiles into less harmful gases like CO2, H2O and N2. During the start-up of engine run, catalytic converters suffer cold start problems as the catalyst does not remain active in cold conditions. This results in emission of unconverted harmful gases into the atmosphere. This work attempts to eliminate cold start problems using a heat storage system to keep the catalytic converter hot even under engine off conditions. A eutectic alloy of Mg-Zn-Al is used as the Phase Change Material (PCM) to store the heat around the catalyst. This alloy has high latent heat of fusion, high specific heat, suitable melting point and high thermal stability. Mg-Zn-Al eutectic alloy changes its state between liquid and solid on application and removal of heat. Thus this phase change material acts as a heat storage mechanism in the catalytic converter. Catalytic converter design also involves Rockwool insulation in order to aid longer heat storage. This thermal energy storage system as a combination of PCM and insulation, keeps the catalytic converter hot for several hours even after the engine is shut of
This document summarizes a research paper that examines pricing strategy in a two-stage supply chain consisting of a supplier and retailer. The supplier offers a credit period to the retailer, who then offers credit to customers. A mathematical model is formulated to maximize total profit for the integrated supply chain system. The model considers three cases based on the relative lengths of the credit periods offered at each stage. Equations are developed to represent the profit functions for the supplier, retailer and overall system in each case. The goal is to determine the optimal selling price that maximizes total integrated profit.
The document discusses melanoma skin cancer detection using a computer-aided diagnosis system based on dermoscopic images. It begins with an introduction to skin cancer and melanoma. It then reviews existing literature on automated melanoma detection systems that use techniques like image preprocessing, segmentation, feature extraction and classification. Features extracted in other studies include asymmetry, border irregularity, color, diameter and texture-based features. The proposed system collects dermoscopic images and performs preprocessing, segmentation, extracts 9 features based on the ABCD rule, and classifies images using a neural network classifier to detect melanoma. It aims to develop an automated diagnosis system to eliminate invasive biopsy procedures.
This document summarizes various techniques for image segmentation that have been studied and proposed in previous research. It discusses edge-based, threshold-based, region-based, clustering-based, and other common segmentation methods. It also reviews applications of segmentation in medical imaging, plant disease detection, and other fields. While no single technique can segment all images perfectly, hybrid and adaptive methods combining multiple approaches may provide better results. Overall, image segmentation remains an important but challenging task in digital image processing and computer vision.
This document presents a test for detecting a single upper outlier in a sample from a Johnson SB distribution when the parameters of the distribution are unknown. The test statistic proposed is based on maximum likelihood estimates of the four parameters (location, scale, and two shape) of the Johnson SB distribution. Critical values of the test statistic are obtained through simulation for different sample sizes. The performance of the test is investigated through simulation, showing it performs well at detecting outliers when the contaminant observation represents a large shift from the original distribution parameters. An example application to census data is also provided.
This document summarizes a research paper that proposes a portable device called the "Disha Device" to improve women's safety. The device has features like live location tracking, audio/video recording, automatic messaging to emergency contacts, a buzzer, flashlight, and pepper spray. It is designed using an Arduino microcontroller connected to GPS and GSM modules. When the button is pressed, it sends an alert message with the woman's location, sets off an alarm, activates the flashlight and pepper spray for self-defense. The goal is to provide women a compact, one-click safety system to help them escape dangerous situations or call for help with just a single press of a button.
- The document describes a study that constructed physical fitness norms for female students attending social welfare schools in Andhra Pradesh, India.
- Researchers tested 339 students in classes 6-10 on speed, strength, agility and flexibility tests. Tests included 50m run, bend and reach, medicine ball throw, broad jump, shuttle run, and vertical jump.
- The results showed that 9th class students had the best average time for the 50m run. 10th class students had the highest flexibility on average. Strength and performance generally improved with increased class level.
This document summarizes research on downdraft gasification of biomass. It discusses how downdraft gasifiers effectively convert solid biomass into a combustible producer gas. The gasification process involves pyrolysis and reactions between hot char and gases that produce CO, H2, and CH4. Downdraft gasifiers are well-suited for biomass gasification due to their simple design and ability to manage the gasification process with low tar production. The document also reviews previous studies on gasifier configuration upgrades and their impact on performance, and the principles of downdraft gasifier operation.
This document summarizes the design and manufacturing of a twin spindle drilling attachment. Key points:
- The attachment allows a drilling machine to simultaneously drill two holes in a single setting, improving productivity over a single spindle setup.
- It uses a sun and planet gear arrangement to transmit power from the main spindle to two drilling spindles.
- Components like gears, shafts, and housing were designed using Creo software and manufactured. Drill chucks, bearings, and bits were purchased.
- The attachment was assembled and installed on a vertical drilling machine. It is aimed at improving productivity in mass production applications by combining two drilling operations into one setup.
The document presents a comparative study of different gantry girder profiles for various crane capacities and gantry spans. Bending moments, shear forces, and section properties are calculated and tabulated for 'I'-section with top and bottom plates, symmetrical plate girder, 'I'-section with 'C'-section top flange, plate girder with rolled 'C'-section top flange, and unsymmetrical plate girder sections. Graphs of steel weight required per meter length are presented. The 'I'-section with 'C'-section top flange profile is found to be optimized for biaxial bending but rolled sections may not be available for all spans.
This document summarizes research on analyzing the first ply failure of laminated composite skew plates under concentrated load using finite element analysis. It first describes how a finite element model was developed using shell elements to analyze skew plates of varying skew angles, laminations, and boundary conditions. Three failure criteria (maximum stress, maximum strain, Tsai-Wu) were used to evaluate first ply failure loads. The minimum load from the criteria was taken as the governing failure load. The research aims to determine the effects of various parameters on first ply failure loads and validate the numerical approach through benchmark problems.
This document summarizes a study that investigated the larvicidal effects of Aegle marmelos (bael tree) leaf extracts on Aedes aegypti mosquitoes. Specifically, it assessed the efficacy of methanol extracts from A. marmelos leaves in killing A. aegypti larvae (at the third instar stage) and altering their midgut proteins. The study found that the leaf extract achieved 50% larval mortality (LC50) at a concentration of 49 ppm. Proteomic analysis of larval midguts revealed changes in protein expression levels after exposure to the extract, suggesting its bioactive compounds can disrupt the midgut. The aim is to identify specific inhibitor proteins in the midg
This document presents a system for classifying electrocardiogram (ECG) signals using a convolutional neural network (CNN). The system first preprocesses raw ECG data by removing noise and segmenting the signals. It then uses a CNN to extract features directly from the ECG data and classify arrhythmias without requiring complex feature engineering. The CNN architecture contains 11 convolutional layers and is optimized using techniques like batch normalization and dropout. The system was tested on ECG datasets and achieved classification accuracy of over 93%, demonstrating its effectiveness at automated ECG classification.
This document presents a new algorithm for extracting and summarizing news from online newspapers. The algorithm first extracts news related to the topic using keyword matching. It then distinguishes different types of news about the same topic. A term frequency-based summarization method is used to generate summaries. Sentences are scored based on term frequency and the highest scoring sentences are selected for the summary. The algorithm was evaluated on news datasets from various newspapers and showed good performance in intrinsic evaluation metrics like precision, recall and F-score. Thus, the proposed method can effectively extract and summarize online news for a given keyword or topic.
1. International Journal of Research in Advent Technology, Vol.2, No.5, May 2014
E-ISSN: 2321-9637
Alternative Thermal Barrier Coatings for CI Engines -
350
A Research Review
Ravikumar T1, Kiran K2, Ravichandra V Koti3, Chetan Appasab Chougale4
PG Scholar, Department of Thermal Power Engineering, Dept. of PG Studies, VTU Mysore-570 0191
PG Scholar, Department of Thermal Power Engineering, Dept. of PG Studies, VTU Gulbarga-585 1052
Asst. Professor, Department of Mechanical Engineering, SVIT, Bangalore-560 0643
PG Scholar, Department of Machine Design, Dept. of PG Studies, VTU Gulbarga-585 1054
Visvesvaraya Technological University, Belgaum, Karnataka-590 018.
ravikumart.1990@gmail.com1 , kirankavalli@gmail.com2, ravik8889@gmail.com3 ,
chetanchougule.a10@gmail.com4
Abstract- The depletion of supply of fossil fuels and their increased cost has driven the attention towards
energy security. The energy security can be partially achieved by improving the efficiency of energy producing
equipment’s. Diesel fuels can be used more efficiently in low heat rejection engines (LHR), in which the
temperature of combustion chamber is increased by creating thin layer of ceramics, a thermal barrier. Also the
use of thermal barrier coatings (TBCs) to increase the combustion temperature in diesel engines has been
pursued for over 20 years. Increased combustion temperature can increase the efficiency of the engine, decrease
the CO and unburnt Hydrocarbons (UBHC). TBCs have not yet met with wide success in diesel engine
applications. To reach the desirable temperature of 850-900°C in the combustion chamber from the current
temperature of 350-400°C, a coating with a thickness of order 1mm is required. This paper gives a complete
review on the TBCs on CI engines.
Index Terms- Thermal barrier coating, Diesel engine, Low heat rejection engine.
1. INTRODUCTION
To meet tough automotive competition and
stringent government regulations, more efficient
engine components, improved engine oils, and high
performance coating materials have been developed
within the automotive industry.
The efficiency of most commercially available
diesel engine ranges from 38% to 42%. Therefore,
between 58% and 62% of the fuel energy content is
lost in the form of waste heat. More than 55% of the
energy which is produced during the combustion
process is removed by cooling water and through the
exhaust gas. [1]
The quantity of the energy acquired from the
fuel is not an intended level because of the factors in
the combustion chamber of the engine. Some of the
factors are, design of the combustion chamber, lack of
adequate turbulence in the combustion chamber, poor
oxygen at the medium, lower combustion
temperature, compression ratio and advance of
injection timing. It is thought that combustion
temperature is one of the most important factors
among the above mentioned factors. All of the
hydrocarbons cannot be reacted with oxygen
chemically during combustion time. With this aim,
coating the combustion chamber components with
low thermal conductivity materials becomes a more
important subject at these days. For this reason,
combustion chamber components of the internal
combustion engines are coated with ceramic materials
using various methods.
Low Heat Rejection (LHR) engines aim to utilize
the maximum energy or we can save the energy by
reducing the heat lost to the coolant. This will reduce
the heat transfer through the engine walls, and a
greater part of the produced energy can be utilized,
involving an increased efficiency [2]. The diesel
engine with its combustion chamber walls insulated
by ceramics is referred to as LHR engine. Thermal
barrier coatings (TBC) are used to improve reliability
and durability of hot section metal components and
enhance engine performance and thermal efficiency
and elimination of the cooling system in diesel
engines. Because the combustion chamber
temperatures of ceramic-coated engines are higher
than those of uncoated (base engine) engines, it may
be possible to use a fuel with a large distillation range
and lower quality fuels. Thermal barrier coatings are
duplex systems, consisting of a ceramic topcoat and a
metallic intermediate bond coat. The topcoat consists
of ceramic material whose function is to reduce the
temperature of the underlying, less heat resistant
metal part. The bond coat is designed to protect the
metallic substrate from oxidation and corrosion and
promote the ceramic topcoat adherence [3]. A thermal
barrier application is shown in figure 1.
1.1. Properties of Coating Materials:
The coating material should have the
following properties [4].
Low thermal conductivity: The coated
material should resist almost or Complete
heat transfer to the substrate.
2. International Journal of Research in Advent Technology, Vol.2, No.5, May 2014
E-ISSN: 2321-9637
351
High thermal stability: The coated material
should be able sustain very high temperature
having very high melting point. There by
base or substrate material is protected from
high temperature corrosion.
High wear resistance: The coated material
should have oxidation and corrosion resistant
property. This can be obtained by properly
heat treatment the coated material.
Hardness: The coated material should
possess optimum range of both micro and
macro hardness.
Good adhesive property: The coated
material should be well adhered to the
substrate. So that bonding strength will be
excellent.
Fig. 1. Thermal barrier coating consisting of metallic bond coat on
the substrate and ceramic top coat on the bond coat.
1.2. Advantages of Thermal Barrier Coatings
for Diesel Engines:
Some advantages of thermal barrier coatings
on diesel engines are below.
Low cetane fuels can be burnt.
Improvements occurs at emissions except
NOx
Increased effective efficiency and thermal
efficiency,
Using lower-quality fuels within a wider
distillation range,
The ignition delay of the fuel is considerably
reduced,
The faster vaporization and the better mixing
of the fuel,
Reduced specific fuel consumption,
Multi-Fuel capability,
Improved reliability,
Increased life time of engine parts and
combustion temperature,
Reduces the transient stress and thermal
stress in the parts,
High surface emissivity,
Decreased the heat removed by the cooling
system,
Decreasing knocking and noise caused by
combustion [1, 5-17].
2. ALTERNATIVE MATERIALS FOR
THERMAL BARRIER COATING
The selection of thermal barrier coating materials
is restricted by some basic requirements. They are
high melting point, no phase transformation between
room temperature and operation temperature, low
thermal conductivity, chemical inertness, thermal
expansion match with the metallic substrate, good
adherence to the metallic substrate and low sintering
rate of the porous microstructure. So far, only a few
materials have been found to basically satisfy these
requirements. There is a great thermal expansion
coefficient match between YSZ, bond coat and
substrate (10.7x10-6 k-1 vs. 17.5x10-6 k-1 for
NiCoCrAlY and 16x10-6 K-1 for IN737) [18]. Good
thermo-mechanical performance and fair oxidation
resistance are other properties of YSZ as a TBC.
2.1. Zirconates:
Zirconates materials with a pyrochlore structure
have a fair thermal expansion co-efficient in the range
of 9E-6 k-1 to 10E-6 k-1. The main advantages of
zirconates are their low sintering activity, low thermal
conductivity, high thermal expansion coefficient and
good thermal cycling resistance. The main problem is
the high thermal expansion coefficient which results
in residual stress in the coating, and this can cause
coating delamination [19]. Some materials in this
category; e.g. BaO·ZrO2, SrO·ZrO2, and
La2O3·2ZrO2, undergo phase transformation or
become non-stoichiometric during heating.
2.2. Garnets:
Polycrystalline garnet ceramics are used in
different applications due to their unique properties.
Particularly YAG (Y3Al5O12) is a good choice for
many high-temperature applications, due to its
excellent high temperature properties and phase
stability up to its melting point (1970°C) [14]. Other
advantages which make YAG a candidate as a TBC
are their low thermal conductivity and its low oxygen
diffusivity [5]. Although the thermal conductivity
value is almost the same as zirconia, the thermal
expansion coefficient is lower.
2.3. Yittria Stabilized Zirconia:
7-8% yittria stabilized zirconia has high thermal
expansion coefficient, low thermal conductivity and
high thermal shock resistance. Disadvantages of
3. International Journal of Research in Advent Technology, Vol.2, No.5, May 2014
E-ISSN: 2321-9637
352
yittria stabilized zirconia are sintering above 1473 K,
phase transformation at 1443 K, corrosion and oxygen
transparent [22].
2.4. Al2O3.SiO2.MgO system:
Most traditional, high temperature refractory
ceramic materials are found in the Al2O3.SiO2.MgO
phase diagram. (Figure 2). Among these oxides, some
have been considered as alternatives to YSZ in TBCs.
Fig. 1. Al2O3.SiO2.MgO phase diagram
2.5. Cordierite:
Cordierite (2MgO.2Al2O3.5SiO2) has a very low
TEC (1.67x10 -6 k-1 [15]) but, for certain
applications, could be an alternative for TBCs.
However, after plasma spraying, the cordierite
deposition is amorphous. While heating, two phase
transformation occur, at 830°C and 1000°C, which
produce a volume change and cause cracking [16]. To
deposit crystalline cordierite, the addition of 6 wt%
TiO2 has been reported to be effective [17].
2.6. Forsterite :
The high thermal expansion coefficient of
forsterite permits a good match with the substrate. At
thicknesses of some hundred microns, it shows a very
good thermal shock resistance [19].
2.7. Spinel:
Although spinel has very good high temperature
and chemical properties, its thermal expansion
coefficient prevents its usage as a reliable choice for
thermal barrier coatings [19].
2.8. Mullite:
Mullite is applied on SiC as an oxidation resistant
layer to form an environmental barrier coating (EBC).
Its low oxygen diffusivity, low creep rate at high
temperatures, high thermo-mechanical fatigue
resistance and close TEC match with SiC (4-5x10-6
K-1 vs. 5- 6x10-6 K-1 [20]) makes it the ideal choice
for this application. In thin coatings (up to some
hundred microns) on top of a metallic substrate, the
durability of mullite has been reported to be better
than that of zirconia [21].
2.9. Alumina:
It has very high hardness and chemical inertness.
Alumina has relatively high thermal conductivity and
low thermal expansion coefficient compared with
yittria stabilized zirconia. Even though alumina alone
is not a good thermal barrier coating candidate, its
addition to yittria stabilized zirconia can increase the
hardness of the coating and improve the oxidation
resis-tance of the substrate. The disadvantages of
alumina are phase transformation at 1273K, high
thermal conductivity and very low thermal expansion
coefficient [18].
3. FUEL CONSUMPTION
Numerous investigators have modeled and
analyzed the effects of in-cylinder thermal insulation
on fuel consumption. The level of improvement that
has been predicted ranged from 2 to 12 %. Kamo et
al. [22] Test results indicate that coatings on the
cylinder liner bore produced a reduction in fuel
consumption while coatings on the piston and
cylinder head-face surface were more effective in
reducing heat rejection. Uzan et al. [8] reported 2%
decrease in the engine specific fuel consumption with
TBCs. Murthy et al. [23] indicate that LHR engine
showed deteriorated performance at recommended
injection timing and pressure and improved
performance at advanced injection timing and higher
injection pressure, when compared with conventional
engine (CE). At peak load operation, brake specific
fuel consumption (BSFC) decreased by 12%.
Thring [24] stated that comparison of SFC
between baseline and LHR engine should be done
carefully, because reducing the heat rejection affects
other engine operating parameters such as volumetric
efficiency, air-fuel mixing and etc., which in turn
affect fuel consumption. Hence it is felt that,
comparison between the two engines should be made
at same engine operating conditions and same engine
operating parameters. In general, it has been reported
that fuel consumption of, naturally aspirated LHR
engine is in the range of 0 to 10% higher,
turbocharged LHR engine in the order of 0 to 10%
lower and turbo-compounded LHR engine in the
order of 0 to 15% lower, when compared with the
conventional cooled engine.
Buyukkaya et al. [11] showed that 1-8% reduction
in brake specific fuel consumption could be achieved
by the combined effect of the thermal barrier coating
(TBC) and injection timing. The investigation of
Alkidas [25] has shown that the fuel economy of the
LHR engine is of the same level as that of water
cooled engine at the medium load, but deteriorated
significantly at the high load condition. He attributed
this to increased temperature of the combustion
4. International Journal of Research in Advent Technology, Vol.2, No.5, May 2014
E-ISSN: 2321-9637
353
chamber walls, thus also increasing the temperature of
the fuel issuing from the heated nozzle orifice
resulting in the reduced fuel viscosity. This caused a
heavy leakage fuel inside the nozzle and extended
injection duration as well. Admitting the need for
tuning of the fuel injection system for LHR engine
operation, he optimized an injector tip configuration
and achieved equal or superior fuel consumption.
Assanis et al. [26] have shown that with proper
adjustment of the injection timing it is possible to
partially offset the adverse effect of insulation release
rate. Their data have shown that reducing heat
rejection from the cylinder, shift the combustion from
pre-mixed towards diffusion. They have shown that
by advancing the timing, the LHR engine achieves the
same pre-mixed heat release rate and rate can also
offset the adverse effect of insulation. Sun et al. [27]
have shown that decrease in pre-mixed combustion by
about 75% in an insulated engine increases the BSFC
by about 9%.
4. ENGINE EFFICIENCY
4.1. Volumetric Efficiency:
The volumetric efficiency is an indication of
breathing ability of the engine. It depends on the
ambient and operating conditions of the engine.
Reducing heat rejection with the addition of ceramic
insulation causes an increase in the temperature of the
combustion chamber walls of an LHR engine. The
volumetric efficiency should drop, as the hotter walls
and residual gas decrease the density of the inducted
air. As expected all the investigations such as Thring
[24], Assanis et al. [26], Gatowski [28], Miyairi et al.
[29], and Suzuki et al. [30], on LHR engine show
decreased volumetric efficiency. The deterioration in
volumetric efficiency of the LHR engine can be
prevented by turbo-charging and that there can be
more effective utilization of the exhaust gas energy.
4.2. Thermal Efficiency:
The improvement in engine thermal efficiency by
reduction of in-cylinder heat transfer is the key
objective of LHR engine research. Much work has
been done at many research institutes to examine the
potential of LHR engines for reducing heat rejection
and achieving high thermal efficiency. Researchers
such as Thring [24], Alkidas [25], Havstad et al. [31],
Moore et al. [32], and many others have reported
improvement in thermal efficiency with LHR engine.
They attribute this to in transfer reduction and lower
heat flux. However investigations of others such as
Cheng et al. [33], Woschni et al. [34]. Dickey [35]
and some others report that thermal efficiency reduces
with insulation. They all attribute this to an increase in
the convective heat transfer coefficient, higher heat
flux (increase in-cylinder heat transfer) and
deteriorated combustion. The in cylinder heat transfer
characteristics of LHR engine are still not clearly
understood. Thus the effect of combustion chamber
insulation on reducing heat rejection and hence on
thermal efficiency is not clearly understood as on
date. Hoag et al. [36], Sudhakar [37], Yoshimitsu et
al. [38], and Yonushonis [39] have reported
improvement in the reduction of fuel consumption
and in the thermal efficiency of LHR engine.
The effects of ceramic coating on the performance
of the diesel engine were investigated by Taymaz [40,
41]. The combustion chamber surfaces, cylinder head,
valves and piston crown faces were coated with
ceramic materials. The layers were made of CaZrO3
and MgZrO3 and plasma coated onto the base of the
NiCrAl bond coat. The ceramic-coated research
engine was tested at the same operation conditions as
the standard (without coating) engine. The results
showed that the increase of the combustion
temperature causes the effective efficiency to rise
from 32% to 34% at medium load and from 37% to
39% at full load and medium engine speeds for
ceramic-coated engine while it increases only from
26% to 27% at low load. The values of the effective
efficiency are slightly higher for the ceramic-coated
case as compared to the standard case (without
coating).
5. CONCLUSION
By insulating combustion chamber components, it
is available to keep combustion temperatures high.
Due to high combustion temperatures thermal
efficiency can be increased, exhaust emissions can be
improved and fuel consumption can be decreased on
diesel engines. Ceramic materials which have low
thermal conductivity and high thermal expansion
coefficient are used for making combustion chamber
components thermal insulated.
In this paper, the advantages and disadvantages of
several materials for use as thick thermal barrier
coatings in diesel engines were reviewed.
For a successful coating thermal coating, ceramic
material has a high melting point, high oxygen
resistance, high thermal expansion coefficient, high
corrosion resistance, high strain tolerance, and low
thermal conductivity and phase stability.
The objectives of improved thermal efficiency,
improved fuel economy and reduced emissions are
attainable, but much more investigations under proper
operating constraints with improved engine design are
required to explore the full potential of Low Heat
Rejection engines.
REFERENCES
[1] Yasar H. “Termal bariyer kaplamanın turbo
doldurmalı bir dizel motorunun performansına
etkileri”, İstanbul Teknik Üniversitesi Fen
Bilimleri Enstitüsü, Doktora Tezi, (1997).
5. International Journal of Research in Advent Technology, Vol.2, No.5, May 2014
E-ISSN: 2321-9637
354
[2] Metin Gumus Mehmet Akcay “Thermal Barrier
Coatings for Diesel Engines” International
Scientific Conference 19 – 20 November 2010,
Gabrovo.
[3] Saint-Ramond, B. “High insulation termal barrier
coating systems”, Air Space Europe, 3, 3/4,
(2001).
[4] Bose S., “High Temperature Coatings”, 312
pages, Science Direct e-book Copyright, (2007).
[5] Parlak A., Yaşar H., Şahin B. “Performance and
exhaust emission characteristics of a lower
compression ratio LHR diesel engine”, Energy
Conversion and Management, 44, 163-175,
(2003).
[6] Chan S., H. “Performance and emissions
characteristics of a partially insulated gasoline
engine”, International Journal of Thermal
Sciences, 40, 255-251, (2001).
[7] Srinivasan, K., K., Mago, P., J., Krishnan, S.,
R.,“Analysis of exhaust waste heat recovery from
a dual fuel low temperature combustion engine
using an Organic Rankine Cycle” Energy, 35,
2387-2399, 2010.
[8] Uzun A., Çevik İ., Akçil M. “Effects of thermal
barrier coating on a turbocharged diesel engine
performance”, Surface and Coating Tecnology,
116-119, 505-507, (1999).
[9] Taymaz I., Çakır K., Mimaroğlu A., “Experi-mental
study of effective efficiency in a ceramic
coated diesel engine”, Surface and Coatings
Tecnology, 200, 1182-1185, (2005).
[10]Chan S., H. and Khor K., A. “The effect of
thermal barrier coated piston crown on engine
characteristics”, Journal of Materials Engineering
and Performance, 9(1), 103-109, (2000).
[11]Büyükkaya E., Engin T., Cerit M. “Effects of
thermal barrier coating on gas emissions and
performance of a LHR engine with different
injection timings and valve adjustments”, Energy
Conversion and Management, 47, 1298-1310,
(2006).
[12]Hazar H. ve Öner C. “İçten yanmalı motorlarda
seramik kaplamanın motor performansına etkisi”,
Doğu Anadolu Bölgesi Araştırmaları, 36–38,
(2004).
[13]Barbezat G. “Application of thermal spraying in
the automobile industry”, Surface and Coatings
Tecnology, 201, 2028–2031, (2006).
[14]Haşimoğlu C., Ciniviz M., Özsert İ., İçingür Y.,
Parlak A., Salman M. S. “Performance charac-teristics
of a low heat rejection diesel engine
operating with biodiesel”, Renewable Energy, 33,
1709-1715, (2008).
[15]Hazar H. and Oztürk U. “The effects of Al2O3-
TiO2 coating in a diesel engine on performance
and emission of corn oil methyl ester”,
Renewable Energy, 35, 2211-2216, (2010).
[16]Karthikeyan B. and Srithar K. “Performance
characteristics of a glow plug assisted low heat
rejection diesel engine using ethanol”, Applied
Energy, (2010).
[17]Hazar H. “Cotton methyl ester usage a diesel
engine equipped with insulated combustion
chamber”, Applied Energy, 87, 134–140, (2010).
[18]X.Q.Cao, R. Vassenb, D. Stoeverb, “ceramic
materials for thermal barrier coatings”, J. Europ.
Ceram. Soc., 24 (2004), 1-10.
[19]H. Samadi, and T.W. Coyle, “Alternative thermal
barrier coatings for diesel engines”, 5th Congress
of Iran Ceramic Society, Iranian Ceramic
Society, 1–8, Tehran, Iran, (2004).
[20]K.N.Lee, D.S.Fox, J.I.Eldridge, D.Zhu,
R.C.Robinson, N.P.Bansal, R.A. Miller, upper
temperature limit of environmental barrier
coatings based on mullite and BSAS”, NASA/
TM-2002-211372.
[21]P. M. Pierz, thermal barrier coating development
for diesel engine aluminum pistons, Surf.
Coat. Tech., 61(1993) 60-66.
[22]Kamo R., Bryzik W., Reid M. and Woods M.,
1997, “Coatings for improving engine
performance”, SAE International, Paper No.
970204.
[23]Murthy P.V.K, Krishna M.V.S., Raju A., Prasad
C.M. and Srinivasulu N.V., 2010, “Performance
evaluation of low heat rejection diesel engine
with pure diesel”, International Journal of
Applied Engineering Research, 1 (3), 428-451.
[24]Thring R.H., 1986, “Low Heat Rejection
Engines”, SAE International, Paper No.860314.
[25]Alkidas A.C., 1989, “Performance and emissions
achievements with an un-cooled heavy duty
single cylindered diesel engine”, SAE
International, Paper No.890144.
[26]Assanis D., Wiese K., Schwarz E. and Bryzik W.,
1991, “The effect of ceramic coatings on diesel
engine performance and exhaust”, SAE
International, Paper No. 910460.
[27]Sun X., Wang W.G., Lyons D.W., and Gao X.,
1993, “Experimental analysis and performance
improvement of single cylinder direct injection
turbocharged low heat rejection engine”, SAE
International, Paper No.930989.
[28]Gatowski J.A., 1990, “Evaluation of a
selectively-cooled single cylindered 0.5-L diesel
engine”, SAE International, Paper No.900693.
[29]Miyairi Y., Matsuhisa T., Ozawa T., Oikawa H.
and Nakashima N., 1989, “Selective heat
insulation of combustion chamber walls for a DI
diesel engine with monolithic ceramics”, SAE
International, Paper No.890141.
[30]Suzuki T., Tsujita M., Mori Y. and Suzuki T.
1986, “An observation of combustion of
phenomenon on heat insulated turbocharged and
inter-cooled DI diesel engines”, SAE
International, Paper No.861187.
6. International Journal of Research in Advent Technology, Vol.2, No.5, May 2014
E-ISSN: 2321-9637
355
[31]Havstad P.H., Garwin I.J. and Wade W.R., 1986,
“Ceramic insert un-cooled diesel engine”, SAE
International, Paper No.860447.
[32]Moore C.H. and Hoehne J.L., 1986, “Combustion
chamber insulation effect on the performance of a
low heat rejection Cummins V-903 engine”, SAE
International, Paper No.860317.
[33]Cheng W.K., Wong V.W. and Gao F., 1989,
“Heat transfer measurement comparisons in
insulated and non-insulated diesel engines”, SAE
International, Paper No.890570.
[34]Woschni G., Spindler W. and Kolesa K., 1987,
“Heat insulation of combustion chamber walls - a
measure to decrease the fuel consumption of IC
engines”, SAE International, Paper No.870339.
[35]Dickey D.W., 1989, “The effect of insulated
combustion chamber surfaces on direct-injected
diesel engine performance, emissions and
combustion”, SAE International, Paper
No.890292.
[36]Hoag K.L., Brands M.C. and Bryzik W.,
“Cummins/TACOM adiabatic engine program”,
SAE International, Paper No. 850356.
[37]Sudhakar V., 1982, “Performance analysis of
adiabatic engine”, SAE International, Paper
No.820431.
[38]Yoshimitsu T., Toyama K., Sato F. and
Yamaguchi H., 1984, “Capabilities of heat
insulated diesel engine”, SAE International,
Paper No.840431.
[39]Yonushonis T.M., 1997, “Overview of thermal
barrier coatings in diesel engines”, Thermal
Spray Technology, 6 (1), 50-56.
[40]Taymaz I., Cakir K. and Mimaroglu A., 2005,
“Experimental study of effective efficiency in a
ceramic coated diesel engine”, Surface and
Coatings Technology, 200, 1182-1185.
[41]Taymaz I., 2007, “The effect of thermal barrier
coatings on diesel engine performance”, Surface
and Coatings Technology, 201, 5249-5252.