The document contains summaries of several papers related to film cooling experiments on turbine blades and endwalls. The papers investigate the effects of various parameters on film cooling effectiveness, including blowing ratio, inlet Reynolds number, incidence angle, leading edge geometry, periodic wakes, and slot shape. The experiments utilize pressure sensitive paint to measure film cooling effectiveness distributions on endwalls under different conditions. Key findings include that film cooling effectiveness generally increases with blowing ratio but can decrease at very high ratios, and is also affected by changes to the inlet flow field such as incidence angle or upstream wakes.
This document summarizes a study investigating the effect of incidence angle on film cooling effectiveness of a nozzle guide vane endwall with and without leading edge fillets. The study uses pressure sensitive paint (PSP) techniques to measure film cooling effectiveness on a scaled turbine vane model at incidence angles of -10, 0, and +10 degrees. Results show that film cooling effectiveness decreases near the leading edge suction side but increases near the leading edge pressure side as incidence angle increases from +10 to -10 degrees. The long fillet configuration shows the lowest sensitivity to changes in incidence angle compared to other fillet geometries.
This document summarizes an experiment that investigated the effect of incidence angle on film cooling effectiveness of the leading edge and gill region of nozzle guide vanes in a gas turbine. The experiment tested incidence angles from -10 to +10 degrees at blowing ratios from 0.7 to 1.3 using pressure sensitive paint to measure film cooling effectiveness. The results showed that incidence angle affected the direction of the cooling jets and film cooling effectiveness distribution. Understanding how off-design conditions like varying incidence angle impact film cooling performance is important for improving turbine component durability and efficiency.
This document summarizes an experimental investigation into the effect of turbine phantom cooling on the suction side of a nozzle guide vane. Phantom cooling refers to coolant injected from the endwall that moves toward the airfoil suction side, providing a secondary cooling effect. The study uses pressure sensitive paint to measure film cooling effectiveness on a scale model turbine vane under different blowing ratios and incidence angles. It finds that incidence angle can alter the direction of coolant jets on the pressure side and change film cooling effectiveness distributions on the airfoil suction side.
1. The document describes an experiment investigating the use of staggered slots upstream of a nozzle guide vane cascade to simulate combustor-turbine leakage flow and improve film cooling effectiveness on the endwall surface.
2. Pressure sensitive painting (PSP) technique was used to measure film cooling effectiveness distributions on the endwall. The experiment tested different blowing ratios and found that staggered slots increased film cooling effectiveness along the pitchwise direction and developed a larger cooled region towards the suction side at higher blowing ratios.
3. The advantage of the staggered slots was apparent near the inlet area at low blowing ratios but their influence was only detected downstream at higher blowing ratios, as the coolant film weakened along the axial chord at low
This document summarizes an experimental investigation into the effects of trailing edge discharge cooling on the film cooling effectiveness of a turbine nozzle guide vane endwall. The study uses pressure sensitive paint to measure film cooling effectiveness on an endwall downstream of turbine blade trailing edges with discharge holes at compound angles. It examines the interaction between coolant from the endwall and trailing edge, referred to as "phantom cooling", and how blowing ratio and compound angle configuration affect film cooling performance. The experiments were conducted on a scale model turbine nozzle guide vane cascade with Reynolds number of 3.5×105 and inlet Mach number of 0.1 while varying the blowing ratio from 0.7 to 1.3 and compound angle of the trailing edge holes.
1) The document discusses a study evaluating a new turbine nozzle guide vane design with radial cylindrical cooling holes on the pressure side to improve film cooling effectiveness in a cooling blind area near the pressure side gill region.
2) Experiments were conducted on a scaled nozzle guide vane cascade model with four rows of radial cooling holes at various blowing ratios. Pressure sensitive painting was used to measure film cooling effectiveness.
3) The results showed that film cooling effectiveness near the pressure side gill region increased with the new design, with a double-peak cooled region developing towards the suction side at higher blowing ratios. Pressure side radial cooling holes improved film cooling in the gill region but effectiveness decreased along the axial chord at low
1. The document discusses an experimental study on the effect of leading edge fillet geometry on endwall film cooling effectiveness for a first-stage turbine vane. Three types of sharp slope fillets with different length-to-height ratios were tested and compared to a baseline geometry without a fillet.
2. Film cooling effectiveness distributions were obtained using pressure sensitive paint. Results showed that film cooling effectiveness increased with increasing blowing ratio. The baseline geometry provided the best film cooling near the leading edge pressure side. The effect of leading edge geometry on the suction side depended on the blowing ratio.
3. Previous literature has found that leading edge modifications can control the horseshoe vortex and secondary flows and thereby impact film cooling effectiveness
International Journal of Engineering Research and Development (IJERD)IJERD Editor
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journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
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This document summarizes a study investigating the effect of incidence angle on film cooling effectiveness of a nozzle guide vane endwall with and without leading edge fillets. The study uses pressure sensitive paint (PSP) techniques to measure film cooling effectiveness on a scaled turbine vane model at incidence angles of -10, 0, and +10 degrees. Results show that film cooling effectiveness decreases near the leading edge suction side but increases near the leading edge pressure side as incidence angle increases from +10 to -10 degrees. The long fillet configuration shows the lowest sensitivity to changes in incidence angle compared to other fillet geometries.
This document summarizes an experiment that investigated the effect of incidence angle on film cooling effectiveness of the leading edge and gill region of nozzle guide vanes in a gas turbine. The experiment tested incidence angles from -10 to +10 degrees at blowing ratios from 0.7 to 1.3 using pressure sensitive paint to measure film cooling effectiveness. The results showed that incidence angle affected the direction of the cooling jets and film cooling effectiveness distribution. Understanding how off-design conditions like varying incidence angle impact film cooling performance is important for improving turbine component durability and efficiency.
This document summarizes an experimental investigation into the effect of turbine phantom cooling on the suction side of a nozzle guide vane. Phantom cooling refers to coolant injected from the endwall that moves toward the airfoil suction side, providing a secondary cooling effect. The study uses pressure sensitive paint to measure film cooling effectiveness on a scale model turbine vane under different blowing ratios and incidence angles. It finds that incidence angle can alter the direction of coolant jets on the pressure side and change film cooling effectiveness distributions on the airfoil suction side.
1. The document describes an experiment investigating the use of staggered slots upstream of a nozzle guide vane cascade to simulate combustor-turbine leakage flow and improve film cooling effectiveness on the endwall surface.
2. Pressure sensitive painting (PSP) technique was used to measure film cooling effectiveness distributions on the endwall. The experiment tested different blowing ratios and found that staggered slots increased film cooling effectiveness along the pitchwise direction and developed a larger cooled region towards the suction side at higher blowing ratios.
3. The advantage of the staggered slots was apparent near the inlet area at low blowing ratios but their influence was only detected downstream at higher blowing ratios, as the coolant film weakened along the axial chord at low
This document summarizes an experimental investigation into the effects of trailing edge discharge cooling on the film cooling effectiveness of a turbine nozzle guide vane endwall. The study uses pressure sensitive paint to measure film cooling effectiveness on an endwall downstream of turbine blade trailing edges with discharge holes at compound angles. It examines the interaction between coolant from the endwall and trailing edge, referred to as "phantom cooling", and how blowing ratio and compound angle configuration affect film cooling performance. The experiments were conducted on a scale model turbine nozzle guide vane cascade with Reynolds number of 3.5×105 and inlet Mach number of 0.1 while varying the blowing ratio from 0.7 to 1.3 and compound angle of the trailing edge holes.
1) The document discusses a study evaluating a new turbine nozzle guide vane design with radial cylindrical cooling holes on the pressure side to improve film cooling effectiveness in a cooling blind area near the pressure side gill region.
2) Experiments were conducted on a scaled nozzle guide vane cascade model with four rows of radial cooling holes at various blowing ratios. Pressure sensitive painting was used to measure film cooling effectiveness.
3) The results showed that film cooling effectiveness near the pressure side gill region increased with the new design, with a double-peak cooled region developing towards the suction side at higher blowing ratios. Pressure side radial cooling holes improved film cooling in the gill region but effectiveness decreased along the axial chord at low
1. The document discusses an experimental study on the effect of leading edge fillet geometry on endwall film cooling effectiveness for a first-stage turbine vane. Three types of sharp slope fillets with different length-to-height ratios were tested and compared to a baseline geometry without a fillet.
2. Film cooling effectiveness distributions were obtained using pressure sensitive paint. Results showed that film cooling effectiveness increased with increasing blowing ratio. The baseline geometry provided the best film cooling near the leading edge pressure side. The effect of leading edge geometry on the suction side depended on the blowing ratio.
3. Previous literature has found that leading edge modifications can control the horseshoe vortex and secondary flows and thereby impact film cooling effectiveness
International Journal of Engineering Research and Development (IJERD)IJERD Editor
call for paper 2012, hard copy of journal, research paper publishing, where to publish research paper,
journal publishing, how to publish research paper, Call For research paper, international journal, publishing a paper, IJERD, journal of science and technology, how to get a research paper published, publishing a paper, publishing of journal, publishing of research paper, reserach and review articles, IJERD Journal, How to publish your research paper, publish research paper, open access engineering journal, Engineering journal, Mathemetics journal, Physics journal, Chemistry journal, Computer Engineering, Computer Science journal, how to submit your paper, peer reviw journal, indexed journal, reserach and review articles, engineering journal, www.ijerd.com, research journals,
yahoo journals, bing journals, International Journal of Engineering Research and Development, google journals, hard copy of journal
This document summarizes an experimental investigation into the effects of nonperiodic inlet rotating flow on endwall film cooling in neighboring turbine passages. The experiment compares film cooling effectiveness for three configurations of anticlockwise rotating inlet flow, analyzed using pressure-sensitive painting. Key findings include: 1) Inlet rotating flow influences effectiveness upstream, especially from leakage flows. 2) Effectiveness differs between passages depending on rotating flow core position. 3) Downstream effectiveness is also partly influenced by upstream rotating flow. Rotating inlet flow introduces challenges for film cooling design between neighboring passages in gas turbines.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
1) The document presents a CFD study analyzing heat transfer enhancement in multi-lead rifled (MLR) boiler tubes compared to plain wall tubes.
2) The study varied geometric parameters of MLR tubes like number of riflings, rifling height, and pitch length to optimize heat transfer.
3) Simulation results at the operating conditions of an actual boiler show increased heat transfer and temperature with MLR tubes versus plain tubes. Implementation of optimized MLR tubes in the boiler is recommended to improve furnace heat transfer.
An Experimental Research on Heat Transfer Enhancement of a Circular Tube with...IRJESJOURNAL
ABSTRACT:- In the literature, internal tube baffles are widely studied. There is a lack of data for baffles mounted on outside of the tubes. This study aims to fill this gap. Therefore, the effect of baffle inclination angles on heat transfer improvement has been studied experimentally. The experiments were carried out for forced convection of air on a circular tube with inclined baffles. Air has been used as the cold fluid. Experimental results for eight different velocities of air flow (2 – 20 m/s) are presented. Pitch between baffles is 12 mm.The baffle inclination angles with respect to the tube axis were 45º, 60º and 80º. Water temperature is fixed as 65 °C. According to the experimental results, the baffles with an inclination angle of 45º enhance the heat transfer over 60º and 80º around 13.7 % and 10.5 %, respectively. However, pressure drop values for 45º and 60º are 18 % higher than pressure drop values for 80º. The empirical correlations of the Nusselt number have also been obtained for each angle.
NUMERICAL ANALYSIS OF THERMAL PERFORMANCE OF LOUVER FINijiert bestjournal
Louver fins are widely used in heat exchanger for a utomotive applications such as radiator,intercooler,condenser,heater core etc. This study presents numerical analysis of effect of variation of louver pitch on heat transfer rate of louver fins. The three dimensional governing equations for fluid flow and heat transfe r are solved using ANSYS Fluent 14.5 for air flow of 4 m/s to 9 m/s. The variations of t emperature,pressure and heat transfer rate are studied using computational model. The enhancem ent of heat rate is observed as louver pitch is reduced.
Numerical Investigation of Boiler Tubes for Performance of Heat Transfer Enha...IJERA Editor
The convective heat transfer of flow in corrugated channels has been investigated using a commercial CFD tool. Heat transfer enhancement of corrugated tube was mainly taken into consideration. Performance of corrugated geometry of the tube was studied by varying its influencing geometrical parameters like number of rifling, height of rifling, length of pitch of rifling for a particular length. The effects of the different geometry of the corrugation, such as circular, rectangular and triangular geometry and heat transfer were determined for flow through tube heat exchanger. The change in corrugation shape gave substantial change in heat transfer rate. The result reveals the effect on corrugation effect on heat transfer rate. The result shows that the heat transfer increased when compared with existing inner plan wall water tube
This document summarizes an experimental study on heat transfer enhancement from surface roughness at laminar flow. Specifically, it examines using circular and oval dimples on an aluminum plate to increase heat transfer from the plate to air flowing over it at Reynolds numbers from 600 to 2000. The study finds that both circular and oval dimples enhance heat transfer compared to a flat plate, while maintaining equivalent or lower pressure drops. The experimental results are validated by comparing the measured Nusselt numbers to theoretical values for a plain vertical plate under laminar flow conditions. In general, the dimpled surfaces increase thermal performance without significantly increasing pressure drops compared to a smooth surface.
Natural convection heat transfer inside inclined open cylinderIAEME Publication
This document summarizes an experimental study on natural convection heat transfer inside an inclined open cylinder. The study investigated the effects of inclination angle (0°, 30°, 60°, 90°) and heat flux (70-600 W/m2) on the heat transfer. Empirical correlations were developed relating the average Nusselt number to the Rayleigh number. Results showed that heat transfer, as measured by the local and average Nusselt number, increased with increasing heat flux and inclination angle from horizontal to vertical.
Natural Convection from Heated Rough Surface at the Bottom of Vented Rectangu...theijes
Natural convection heat transfer from tilted rectangular enclosure heated at the bottom rough surfaces wall and vented by uniform slots opening at top wall experimentally investigated. Rough surfaces of roughness 0.002 m are used to study their effect on the heat transfer characteristics. The experiments are carried out to study the effects of venting ratio, enclosure's tilt angle and Rayleigh number on the cooling of rough surface inside the enclosure. The experiments are carried out at a Rayleigh number ranging from 2 × 108 to 1.52× 109 for enclosure tilt angles ranging from 0º to 90. Top venting arrangement is studied at different venting ratios of 1, 0.75, 0.5 and 0.25. Roughness shows a large effect on heat transfer for the rectangular enclosure where the average Nusselt number increases with the increase of venting ratio and decrease enclosure's tilt angle at the same Rayleigh number. This can be attributed to the roughness may increase the blockage effect on the flow that can cause the buoyancy force to decrease, but on the other hand it increases the turbulence intensity resulting in a higher heat transfer. The results are compared with a smooth rectangular enclosure of the same surface area to study the effect of roughness on heat transfer. The average Nu of rough surface in rectangular enclosure is higher than that of smooth surface by the range from 12 % to 21% depending on Ra. Correlations are developed for the top venting arrangement to predict the average Nusselt number of the enclosure in terms of the Rayleigh number, venting ratio and enclosure tilt angle.
SUCKER ROD COUPLING FRICTION IN HDPE LINED TUBING westernfalcontx
Sucker rod coupling friction values are used by rod design software to calculate rod loads for bare steel tubing on steel couplings. Visit: https://westernfalcon.com
Effect of controlling parameters on heat transfer during spray impingement co...BIBHUTI BHUSAN SAMANTARAY
The heat transfer characteristics of air-water spray impingement cooling of stationary steel plate was experimentally investigated. Experiments were conducted on an electrically heated flat stationary steel plate of dimension 120 mm x 120 mm x 4 mm. The controlling parameters taken during the experiments were air-water pressures, water flow rate, nozzle tip to target distance and mass impingement density. The effects of the controlling parameters on the cooling rates were critically examined during spray impingement cooling. Air assisted DM water was used as the quenchant media in the work. The cooling rates were calculated from the time dependent temperature profiles were recorded by NI-cRIO DAS at the desired locations of the bottom surface of the plate embedded with K-type thermocouples. By using MS-EXCEL the effects of these cooling rate parameters were analysed The results obtained in the study confirmed the higher efficiency of the spray cooling system and the cooling strategy was found advantageous over the conventional cooling methods in the present steel industries.
Analysis of Natural Convention Heat Transfer Enhancement in Finned Tube Heat ...journal ijrtem
ABSTRACT: Most of the engineering problems require high performance heat transfer components with progressively less weight, volumes, accommodating shapes and costs. Air cooled heat exchangers are subjected to air on outer side of heat exchanger surface on in heat recovery systems like economizers gases are subjected on one side of tube surface. On air or gas side heat transfer coefficient is less. Extended surface (fins) are one of the next exchanging devices that are employed extensively to increase heat transfer rates from tubular heat exchangers. The rate of heat transfer depends on the surface area of fin available for exchanging the heat transfer rate from the primary surface of cylindrical shape. Present study focuses on enhancement of heat transfer by using both circular and elliptical type of fins. The present paper attempts to examine trend of heat transfer coefficient experimentally and by using CFD software for various types of elliptical fins with i) varying elliptical ratio, ii) changing orientation of mounting of heat exchanger tube with elliptical fins, iii) varying spacing or fin density. KEY WORDS: Natural convection, Heat transfer enhancements, Elliptical fin, Fin orientation, Fin density.
This document discusses a study on the effect of micro-grooved fins on the thermal and hydraulic performance of fin-and-tube heat exchangers. It fabricated fins with parallel micro-grooves using photolithography and chemical etching. It then tested four full-scale heat exchangers with these fins, measuring dry and wet air-side pressure drop and heat transfer coefficients. The micro-grooved fins reduced wet air-side pressure drop by 9.3-53% while having a negligible impact on dry and wet heat transfer coefficients. This novel fin design improved performance by better managing condensate, demonstrating potential benefits for HVAC&R systems. It also evaluated the durability of an alkyl silane coating applied
15. experimental investigation of heat transfer characteristics ofNEERAJKUMAR1898
1) The document describes an experimental investigation of heat transfer characteristics of a trapezoidal channel with a sharp edged wavy plate.
2) The study measured heat transfer and pressure drop for different plate configurations including a plane plate, trapezoidal plate, and trapezoidal plate with a sharp edged wavy plate.
3) The results showed that the trapezoidal plate and plate with a sharp edge increased heat transfer compared to the plane plate, with the sharp edged wavy plate configuration providing the highest enhancement of up to 85% in heat transfer.
This document summarizes a study on the thermal analysis of circular inclined pipes subjected to natural convection using computational fluid dynamics (CFD). The study investigated the effect of parameters like tube diameter, heat supplied, and tube inclination on the temperature and heat transfer coefficient through experimental testing and CFD analysis. The experimental results were validated against CFD results, with less than 5% error found between the two. It was found that temperature increased with increasing pipe diameter and heat supply. The temperature was also strongly influenced by heat flux and diameter, and weakly dependent on tube inclination.
Thermal Analysis of Clay Pot in Pot RefrigeratorIJMER
Cooling through evaporation is an ancient effective method of lowering temperature. The simple clay pot refrigerator is ideally suited for preserving vegetarian food and water in hot and dry climates. The refrigeration takes place by evaporation through the porous pot material. The present work includes experimental analysis of a clay pot in pot by varying height of water in the inner pot, by varying water level in the annulus of two pots and by subjecting the pot in pot refrigerator for free and forced convection. Results obtained from experimental analysis shows that Temperature T1 is highest when inner
pot is filled with 5.5litres of water and lowest when it is filled with 1.5 litres of water. Temperature T1 decreases by increasing water level in the annulus of two pots and rate of cooling is lowest when pot in pot refrigerator is subjected to free convection and highest when it is subjected to forced convection.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
This so called PPT for propulsion study for Shenyang Aerospace University. This PPT right protected by Dr. divinder K. Yadav. Its using in SAU by Lale. For all students of Aeronautical Engineering must memorize each & every words from this PPT. If you miss a single words you must fail in the Exam. Remember there is no chance to be creative or use sense you just need to use the power of memorizing.
NASA's mission is to pioneer space exploration, scientific discovery, and aeronautics research. It has six strategic goals including completing the International Space Station, developing a new crew vehicle after the shuttle's retirement, and establishing a lunar return program. NASA is organized into four mission directorates: Aeronautics, Exploration Systems, Science, and Space Operations. The document provides a brief history of NASA and outlines some of its current and future missions including completing the ISS, returning to the moon by 2020, and developing new technologies to explore beyond low Earth orbit.
The document discusses gas turbine engines and their applications. It describes the key components of gas turbines which include a compressor, combustion chamber, and gas turbine with an intercooler and regenerator. It then explains the working principles of open and closed cycle gas turbines. Open cycle gas turbines only use air as the working fluid while closed cycle can use any fluid but have higher maintenance costs. Gas turbines are used for applications such as aircraft engines, power generation, and supercharging internal combustion engines.
This document provides an overview of gas turbine engine design, focusing on compressor and turbine components. It discusses:
1) How gas turbine engines work by compressing air, mixing it with fuel, combusting the mixture to produce thrust or shaft power via Newton's third law.
2) The major components of compressors (axial, centrifugal) and turbines (axial, radial), how they operate to compress or expand the working fluid, and examples of each type.
3) Key design challenges like thermal issues, blade stalls, and dynamic surge; and methods to address them like various cooling techniques.
4) The basic process of axial compressor design which involves defining needs, determining rotational speed, estimating
This document summarizes an experimental investigation into the effects of nonperiodic inlet rotating flow on endwall film cooling in neighboring turbine passages. The experiment compares film cooling effectiveness for three configurations of anticlockwise rotating inlet flow, analyzed using pressure-sensitive painting. Key findings include: 1) Inlet rotating flow influences effectiveness upstream, especially from leakage flows. 2) Effectiveness differs between passages depending on rotating flow core position. 3) Downstream effectiveness is also partly influenced by upstream rotating flow. Rotating inlet flow introduces challenges for film cooling design between neighboring passages in gas turbines.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
1) The document presents a CFD study analyzing heat transfer enhancement in multi-lead rifled (MLR) boiler tubes compared to plain wall tubes.
2) The study varied geometric parameters of MLR tubes like number of riflings, rifling height, and pitch length to optimize heat transfer.
3) Simulation results at the operating conditions of an actual boiler show increased heat transfer and temperature with MLR tubes versus plain tubes. Implementation of optimized MLR tubes in the boiler is recommended to improve furnace heat transfer.
An Experimental Research on Heat Transfer Enhancement of a Circular Tube with...IRJESJOURNAL
ABSTRACT:- In the literature, internal tube baffles are widely studied. There is a lack of data for baffles mounted on outside of the tubes. This study aims to fill this gap. Therefore, the effect of baffle inclination angles on heat transfer improvement has been studied experimentally. The experiments were carried out for forced convection of air on a circular tube with inclined baffles. Air has been used as the cold fluid. Experimental results for eight different velocities of air flow (2 – 20 m/s) are presented. Pitch between baffles is 12 mm.The baffle inclination angles with respect to the tube axis were 45º, 60º and 80º. Water temperature is fixed as 65 °C. According to the experimental results, the baffles with an inclination angle of 45º enhance the heat transfer over 60º and 80º around 13.7 % and 10.5 %, respectively. However, pressure drop values for 45º and 60º are 18 % higher than pressure drop values for 80º. The empirical correlations of the Nusselt number have also been obtained for each angle.
NUMERICAL ANALYSIS OF THERMAL PERFORMANCE OF LOUVER FINijiert bestjournal
Louver fins are widely used in heat exchanger for a utomotive applications such as radiator,intercooler,condenser,heater core etc. This study presents numerical analysis of effect of variation of louver pitch on heat transfer rate of louver fins. The three dimensional governing equations for fluid flow and heat transfe r are solved using ANSYS Fluent 14.5 for air flow of 4 m/s to 9 m/s. The variations of t emperature,pressure and heat transfer rate are studied using computational model. The enhancem ent of heat rate is observed as louver pitch is reduced.
Numerical Investigation of Boiler Tubes for Performance of Heat Transfer Enha...IJERA Editor
The convective heat transfer of flow in corrugated channels has been investigated using a commercial CFD tool. Heat transfer enhancement of corrugated tube was mainly taken into consideration. Performance of corrugated geometry of the tube was studied by varying its influencing geometrical parameters like number of rifling, height of rifling, length of pitch of rifling for a particular length. The effects of the different geometry of the corrugation, such as circular, rectangular and triangular geometry and heat transfer were determined for flow through tube heat exchanger. The change in corrugation shape gave substantial change in heat transfer rate. The result reveals the effect on corrugation effect on heat transfer rate. The result shows that the heat transfer increased when compared with existing inner plan wall water tube
This document summarizes an experimental study on heat transfer enhancement from surface roughness at laminar flow. Specifically, it examines using circular and oval dimples on an aluminum plate to increase heat transfer from the plate to air flowing over it at Reynolds numbers from 600 to 2000. The study finds that both circular and oval dimples enhance heat transfer compared to a flat plate, while maintaining equivalent or lower pressure drops. The experimental results are validated by comparing the measured Nusselt numbers to theoretical values for a plain vertical plate under laminar flow conditions. In general, the dimpled surfaces increase thermal performance without significantly increasing pressure drops compared to a smooth surface.
Natural convection heat transfer inside inclined open cylinderIAEME Publication
This document summarizes an experimental study on natural convection heat transfer inside an inclined open cylinder. The study investigated the effects of inclination angle (0°, 30°, 60°, 90°) and heat flux (70-600 W/m2) on the heat transfer. Empirical correlations were developed relating the average Nusselt number to the Rayleigh number. Results showed that heat transfer, as measured by the local and average Nusselt number, increased with increasing heat flux and inclination angle from horizontal to vertical.
Natural Convection from Heated Rough Surface at the Bottom of Vented Rectangu...theijes
Natural convection heat transfer from tilted rectangular enclosure heated at the bottom rough surfaces wall and vented by uniform slots opening at top wall experimentally investigated. Rough surfaces of roughness 0.002 m are used to study their effect on the heat transfer characteristics. The experiments are carried out to study the effects of venting ratio, enclosure's tilt angle and Rayleigh number on the cooling of rough surface inside the enclosure. The experiments are carried out at a Rayleigh number ranging from 2 × 108 to 1.52× 109 for enclosure tilt angles ranging from 0º to 90. Top venting arrangement is studied at different venting ratios of 1, 0.75, 0.5 and 0.25. Roughness shows a large effect on heat transfer for the rectangular enclosure where the average Nusselt number increases with the increase of venting ratio and decrease enclosure's tilt angle at the same Rayleigh number. This can be attributed to the roughness may increase the blockage effect on the flow that can cause the buoyancy force to decrease, but on the other hand it increases the turbulence intensity resulting in a higher heat transfer. The results are compared with a smooth rectangular enclosure of the same surface area to study the effect of roughness on heat transfer. The average Nu of rough surface in rectangular enclosure is higher than that of smooth surface by the range from 12 % to 21% depending on Ra. Correlations are developed for the top venting arrangement to predict the average Nusselt number of the enclosure in terms of the Rayleigh number, venting ratio and enclosure tilt angle.
SUCKER ROD COUPLING FRICTION IN HDPE LINED TUBING westernfalcontx
Sucker rod coupling friction values are used by rod design software to calculate rod loads for bare steel tubing on steel couplings. Visit: https://westernfalcon.com
Effect of controlling parameters on heat transfer during spray impingement co...BIBHUTI BHUSAN SAMANTARAY
The heat transfer characteristics of air-water spray impingement cooling of stationary steel plate was experimentally investigated. Experiments were conducted on an electrically heated flat stationary steel plate of dimension 120 mm x 120 mm x 4 mm. The controlling parameters taken during the experiments were air-water pressures, water flow rate, nozzle tip to target distance and mass impingement density. The effects of the controlling parameters on the cooling rates were critically examined during spray impingement cooling. Air assisted DM water was used as the quenchant media in the work. The cooling rates were calculated from the time dependent temperature profiles were recorded by NI-cRIO DAS at the desired locations of the bottom surface of the plate embedded with K-type thermocouples. By using MS-EXCEL the effects of these cooling rate parameters were analysed The results obtained in the study confirmed the higher efficiency of the spray cooling system and the cooling strategy was found advantageous over the conventional cooling methods in the present steel industries.
Analysis of Natural Convention Heat Transfer Enhancement in Finned Tube Heat ...journal ijrtem
ABSTRACT: Most of the engineering problems require high performance heat transfer components with progressively less weight, volumes, accommodating shapes and costs. Air cooled heat exchangers are subjected to air on outer side of heat exchanger surface on in heat recovery systems like economizers gases are subjected on one side of tube surface. On air or gas side heat transfer coefficient is less. Extended surface (fins) are one of the next exchanging devices that are employed extensively to increase heat transfer rates from tubular heat exchangers. The rate of heat transfer depends on the surface area of fin available for exchanging the heat transfer rate from the primary surface of cylindrical shape. Present study focuses on enhancement of heat transfer by using both circular and elliptical type of fins. The present paper attempts to examine trend of heat transfer coefficient experimentally and by using CFD software for various types of elliptical fins with i) varying elliptical ratio, ii) changing orientation of mounting of heat exchanger tube with elliptical fins, iii) varying spacing or fin density. KEY WORDS: Natural convection, Heat transfer enhancements, Elliptical fin, Fin orientation, Fin density.
This document discusses a study on the effect of micro-grooved fins on the thermal and hydraulic performance of fin-and-tube heat exchangers. It fabricated fins with parallel micro-grooves using photolithography and chemical etching. It then tested four full-scale heat exchangers with these fins, measuring dry and wet air-side pressure drop and heat transfer coefficients. The micro-grooved fins reduced wet air-side pressure drop by 9.3-53% while having a negligible impact on dry and wet heat transfer coefficients. This novel fin design improved performance by better managing condensate, demonstrating potential benefits for HVAC&R systems. It also evaluated the durability of an alkyl silane coating applied
15. experimental investigation of heat transfer characteristics ofNEERAJKUMAR1898
1) The document describes an experimental investigation of heat transfer characteristics of a trapezoidal channel with a sharp edged wavy plate.
2) The study measured heat transfer and pressure drop for different plate configurations including a plane plate, trapezoidal plate, and trapezoidal plate with a sharp edged wavy plate.
3) The results showed that the trapezoidal plate and plate with a sharp edge increased heat transfer compared to the plane plate, with the sharp edged wavy plate configuration providing the highest enhancement of up to 85% in heat transfer.
This document summarizes a study on the thermal analysis of circular inclined pipes subjected to natural convection using computational fluid dynamics (CFD). The study investigated the effect of parameters like tube diameter, heat supplied, and tube inclination on the temperature and heat transfer coefficient through experimental testing and CFD analysis. The experimental results were validated against CFD results, with less than 5% error found between the two. It was found that temperature increased with increasing pipe diameter and heat supply. The temperature was also strongly influenced by heat flux and diameter, and weakly dependent on tube inclination.
Thermal Analysis of Clay Pot in Pot RefrigeratorIJMER
Cooling through evaporation is an ancient effective method of lowering temperature. The simple clay pot refrigerator is ideally suited for preserving vegetarian food and water in hot and dry climates. The refrigeration takes place by evaporation through the porous pot material. The present work includes experimental analysis of a clay pot in pot by varying height of water in the inner pot, by varying water level in the annulus of two pots and by subjecting the pot in pot refrigerator for free and forced convection. Results obtained from experimental analysis shows that Temperature T1 is highest when inner
pot is filled with 5.5litres of water and lowest when it is filled with 1.5 litres of water. Temperature T1 decreases by increasing water level in the annulus of two pots and rate of cooling is lowest when pot in pot refrigerator is subjected to free convection and highest when it is subjected to forced convection.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
This so called PPT for propulsion study for Shenyang Aerospace University. This PPT right protected by Dr. divinder K. Yadav. Its using in SAU by Lale. For all students of Aeronautical Engineering must memorize each & every words from this PPT. If you miss a single words you must fail in the Exam. Remember there is no chance to be creative or use sense you just need to use the power of memorizing.
NASA's mission is to pioneer space exploration, scientific discovery, and aeronautics research. It has six strategic goals including completing the International Space Station, developing a new crew vehicle after the shuttle's retirement, and establishing a lunar return program. NASA is organized into four mission directorates: Aeronautics, Exploration Systems, Science, and Space Operations. The document provides a brief history of NASA and outlines some of its current and future missions including completing the ISS, returning to the moon by 2020, and developing new technologies to explore beyond low Earth orbit.
The document discusses gas turbine engines and their applications. It describes the key components of gas turbines which include a compressor, combustion chamber, and gas turbine with an intercooler and regenerator. It then explains the working principles of open and closed cycle gas turbines. Open cycle gas turbines only use air as the working fluid while closed cycle can use any fluid but have higher maintenance costs. Gas turbines are used for applications such as aircraft engines, power generation, and supercharging internal combustion engines.
This document provides an overview of gas turbine engine design, focusing on compressor and turbine components. It discusses:
1) How gas turbine engines work by compressing air, mixing it with fuel, combusting the mixture to produce thrust or shaft power via Newton's third law.
2) The major components of compressors (axial, centrifugal) and turbines (axial, radial), how they operate to compress or expand the working fluid, and examples of each type.
3) Key design challenges like thermal issues, blade stalls, and dynamic surge; and methods to address them like various cooling techniques.
4) The basic process of axial compressor design which involves defining needs, determining rotational speed, estimating
Cascade control uses two or more interconnected control loops to control a process variable. In a basic cascade control scheme, the output of the primary controller determines the set point of the secondary controller. The secondary controller then adjusts the control variable. This allows the secondary controller to respond quickly to disturbances while the primary controller responds more slowly.
An example is given of using cascade control to maintain the temperature of a fluid heated by steam. A secondary flow controller loop would respond quickly to changes in steam flow, while the primary temperature controller loop would adjust more slowly to variations in fluid temperature. Cascade control in this case allows compensation for disturbances in both steam and fluid flow rates to better maintain the desired fluid temperature.
Basic Mechanical Engineering-Steam turbines Steve M S
Steam turbines use the pressure energy of steam to power rotation of a shaft. There are two main types: impulse turbines, where steam jet kinetic energy changes the turbine blades' momentum; and reaction turbines, where continuous steam pressure drop over fixed and moving blades provides rotational force. Compounding involves using multiple stages to reduce turbine speed for practical use, through either velocity compounding by absorbing steam kinetic energy in stages, pressure compounding by expanding steam pressure in nozzles, or a combination of both approaches in pressure-velocity compounding turbines.
Steam turbines work by converting the energy of expanding steam into rotational motion. They have several key components and come in two main types: impulse and reaction. Impulse turbines use nozzles to direct high velocity steam onto turbine blades for impulse, while reaction turbines utilize both fixed and moving blades to expand steam. Common problems in steam turbines include stress corrosion cracking, corrosion fatigue, thermal fatigue, and pitting due to chemical attack from corrosive elements in the steam. Proper lubrication and preventing blade deterioration are important for optimizing steam turbine performance and lifespan.
Cascade is crisis management software that allows users to:
1. Prepare for crises by mapping risks, infrastructure, and response plans over time.
2. Conduct exercises and training simulations to test response plans.
3. Manage crises in real-time by monitoring events, impacts, and coordinating responses.
4. Review crises by evaluating responses, impacts, and providing feedback.
It is a web-based tool that can be accessed from any device and allows multiple simultaneous users to collaborate on crisis mapping.
This document discusses the key aspects of a 134 MW steam turbine. It begins by defining a steam turbine as a device that extracts thermal energy from pressurized steam and converts it into mechanical energy. It then provides specific design data for a 134 MW turbine, including its rated output, speed, steam conditions, number of extractions and stages. The document goes on to classify turbines based on their steam flow, type of energy conversion, compounding, cylinder arrangement, and exhaust conditions. It describes impulse, reaction, and combined impulse-reaction turbines as well as tandem and cross-compound cylinder arrangements.
CFD Simulation on Gas turbine blade and Effect of Hole Shape on leading edge ...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
EXPERIMENTAL AND NUMERICAL INVESTIGATION OF ADIABATIC FILM COOLING EFFECTIVEN...IAEME Publication
This study aims at investigating the film cooling effectiveness using both experimentally and numerically for the scaled up gas turbine blade leading edge compound angle model. A compound angle gas turbine blade leading edge model having the five rows of holes, one at stagnation line, two rows of holes at 30 degrees on either side of stagnation line and two rows of holes at 60 degrees on either side of stagnation line. Each row has the five holes at a pitch of 21mm with the varied hole angles of 0, 30, 45, 55 and 60 degrees oriented with the stream line direction.
Gas turbine cooling system by ahmed shoshan & alaa el-adlAhmed Shoshan
The document summarizes research on gas turbine cooling systems. It examines injection cooling methods, including forward and backward injection. Studies compare the cooling effectiveness of different injection directions and blowing ratios. Backward injection leads to more uniform cooling across the span and higher overall effectiveness compared to forward injection. Conclusions determine that backward injection improves film cooling performance on flat surfaces by promoting stronger interaction between the coolant jet and mainstream flow.
This document summarizes an experimental study that used Pressure Sensitive Paint (PSP) to measure the film cooling effectiveness on a turbine vane endwall under the influence of periodic unsteady wakes from an upstream wake generator. The study varied the mass flow ratio of coolant through the combustor-turbine interface slot from 0.3% to 0.7% and the frequency of passing wakes from 0 Hz to 50 Hz. The results showed that film cooling effectiveness increased with higher mass flow ratios and decreased with higher wake frequencies, especially near the leading edge on the suction side. Spanwise averaged plots provided clearer comparisons of the film cooling effectiveness under different test conditions.
A Review Of Hole Geometry And Coolant Density Effect On Film CoolingBrittany Allen
This document reviews the development of film cooling hole geometries and the effect of coolant density on film cooling performance over the past few decades. Early work in the 1970s studied the effects of shaping cooling hole exits to produce a Coanda effect, keeping the coolant jet close to the surface. Subsequent work explored compound angle holes, holes with diffuser exits, and holes placed in slots. Later studies in the 1990s showed that compound angle holes and shaped holes with forward expansions significantly improved film cooling effectiveness at higher blowing ratios by reducing jet lift-off. More recent work demonstrates that expanded exit holes further reduce jet penetration and improve effectiveness compared to cylindrical holes. Modifying hole geometry to influence the coolant jet trajectory and spreading
Improved Thermal Performance of Solar Air Heater Using V-Rib with Symmetrical...IJERA Editor
This document summarizes an experimental investigation of the thermal performance of a solar air heater duct with an absorber plate containing V-shaped ribs with symmetrical gaps and staggered ribs. Experiments were conducted for a Reynolds number range of 3000-14000 with various rib parameters. Results showed that the heat transfer coefficient and Nusselt number were higher for the roughened plate compared to a smooth plate, indicating enhanced heat transfer. The efficiency was also higher for the roughened plate configuration compared to the smooth plate due to the increased heat transfer. The V-rib with symmetrical gap and staggered rib geometry increased secondary flows and accelerated the air flow, improving thermal performance compared to a smooth plate.
This document summarizes a research project that aims to thermally enhance a plate-fin heat exchanger using secondary structures called cross-cuts. Cross-cuts are sections removed from fins perpendicular to airflow to disrupt boundary layer development. The project will test various cross-cut configurations and validate correlations from a previous study. A plate-fin heat sink will be compared to designs with one and two cross-cuts. The goal is to validate that a single cross-cut provides the best thermal performance improvement of 4-13% over the base design within a pumping power range of 0.01-1W.
Effect of artificial roughness on Thermal and Thermohydraulic efficiency in R...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
Enhancement of Heat Transfer and Thermo-Hydraulic Performance Using Triangula...IJERA Editor
Solar heat has been thrust area of research to explore renewable energy utilisation for the past few decades. In
solar air heaters artificial roughness is tried on the surface of the absorber plate by adding small roughness
elements to enhance the heat transfer rate. In the present work triangular protrusion are provided to act as
roughness elements over the surface of the aluminum absorber plate. The experimental study is carried out on
the effect of change in apex angle of protrusions on the heat transfer rate by keeping the other design parameters
unchanged. Maximum heat transfer rate and thermo-hydraulic performance between the range of apex angle 300
and 600 is studied. The Nusselt number is between 50 and 110, friction factor 4.5-6.7x10-3, Stanton number is 6-
14x10-3. The heat transfer rate and thermo-hydraulic performance are observed to be maximum for 450 apex
angle and least for the 600 plate.
STUDY OF HEAT TRANSFER ON BROKEN ARC ROUGHNESS ELEMENTS ON THE ABSORBER PLATE...IAEME Publication
Performance of solar air heater can be enhanced by adding roughness to the inner periphery. The present study on the effect of various shape parameters for broken arc roughness elements of heat transfer and friction factor characteristics of rectangular duct. The duct has Reynolds number (Re) range of 3000-22300, respective roughness height (e/D) values is 0.045, arc angle (α) is 60˚ and roughness width (W/w) is 5 and relatively roughness pitch is 8.
Computational Performance Analysis of Heat Sink with Pin Fin for Various Surf...IRJET Journal
This document analyzes the computational performance of a heat sink with pin fins of various surface profiles through simulation. Four pin fin heat sink configurations are modeled with pins of different diameters and drafted at an angle of 20 degrees. Simulations are run at constant heat input and varying air velocities to analyze pressure drop, thermal resistance, Nusselt number, and profit factor. The results show that a configuration with pins of diameter 2,2,2 mm (type-4) has the best performance with maximum heat transfer and minimum thermal resistance. The optimized model with rectangular surface roughness on fins further improves performance over previous models.
Cfd analysis of turbulence in a gas turbine combustor with reference to the c...IAEME Publication
This document discusses computational fluid dynamics (CFD) analysis of turbulence in a gas turbine combustor with reference to exit phenomena. It summarizes several studies that have used experimental and computational methods to model combustor exit profiles and their effects on secondary flows in turbine vanes. The document outlines CFD models of different combustor configurations, including variations in cooling schemes, dilution jets, and exit slots. Results show that dilution jets and exit slots can create non-uniformities in temperature, pressure and velocity at the combustor exit which influence the development of secondary flows in downstream vanes. Understanding these interactions is important for improving turbine performance and cooling effectiveness.
Cfd analysis of turbulence in a gas turbine combustor with reference to the c...IAEME Publication
This document discusses computational fluid dynamics (CFD) analysis of turbulence in a gas turbine combustor with reference to exit phenomena. It analyzes the interaction between the combustor and turbine regarding increased temperatures and heat transfer. The objective is to better understand non-uniformities in the flow field at the combustor exit in terms of temperature, pressure and velocity in the spanwise and pitchwise directions. The analysis uses CFD to model different combustor configurations and evaluate the effects on the exit flow field and downstream turbine vane.
IRJET- Enhancement of Heat Transfer Effectiveness of Plate-Pin Fin Heat S...IRJET Journal
This document summarizes a study on enhancing the heat transfer effectiveness of plate-pin fin heat sinks. Nineteen different plate-pin fin heat sink models were numerically simulated and analyzed based on factors like heat transfer coefficient, Nusselt number, pressure drop, base plate temperature, fan power, and thermal resistance. The results showed that a plate-pin fin heat sink model with a plate cut thickness of D/3, where D is the pin diameter, performed the best with higher heat transfer coefficient, Nusselt number, and lower base plate temperature, pressure drop, fan power, and thermal resistance compared to other models. A heat sink model with pin fins containing two holes also showed improved performance over solid pin fins.
ARTICLE 58 IJAET VOLII ISSUE III JULY SEPT 2011Nirav Soni
The document reports on an experimental investigation of a double pass solar air heater with a corrugated absorber plate and Amul Cool aluminum cans. The study found that using a corrugated plate and aluminum cans in the double pass design increased the absorber plate temperature and thermal efficiency compared to a conventional single pass solar air heater. Tests were conducted to analyze how factors like time of day, solar insolation, and mass flow rate affected the absorber temperature and thermal efficiency of the modified solar air heater design.
Experimental Investigation of Heat Transfer through Rectangular and Trapezoid...IRJET Journal
The document describes an experimental investigation of heat transfer through rectangular and trapezoidal fins made of aluminum 6063 alloy. Rectangular and trapezoidal fins were fabricated from the alloy and experiments were conducted under steady state conditions. Local temperature, heat flux, heat transfer coefficients, and Reynolds numbers were estimated. The findings showed that forced convection was more effective than free convection, and the trapezoidal fin enhanced heat transfer by up to 48% compared to the rectangular fin under different heat supply conditions. The document provides details on the experimental setup, material properties of the aluminum 6063 alloy, and methodology for collecting temperature readings along the fins.
Effect of artificial roughness on heat transfer and friction factor charIAEME Publication
1) The study examines the effect of adding transverse ribs to the absorber plate of a double pass solar air heater on heat transfer and friction factor characteristics.
2) Maximum heat transfer and friction factor occurred at a relative roughness pitch of 10, with heat transfer enhanced 1.6 times over a smooth plate.
3) Artificial roughness is used to increase turbulence and break the laminar sub-layer on the absorber plate, improving heat transfer and thermal efficiency.
IRJET- Experiment Investigation of Heat Transfer Rate of Fins with Blind Hole...IRJET Journal
This document summarizes an experimental study investigating heat transfer from fin arrays with perforations and blind holes. The study compares the heat transfer rates of solid, perforated, and blind hole fin arrays at various inclinations from 0 to 90 degrees. The experiment uses an aluminum fin array with a heating element and measures temperatures with thermocouples to calculate heat transfer coefficients and rates. Previous studies showing perforations and discrete cuts increase heat transfer are discussed. The experimental setup, including the fin array, heater, control panel, and temperature measurement equipment are described.
Computational study of film cooling in hypersonic flowsIAEME Publication
The document discusses a computational study of film cooling in hypersonic laminar flows using ANSYS-CFX software. Film cooling involves injecting a secondary fluid through discrete slots to thermally insulate a solid surface from a high-temperature gas stream. The study examines film cooling effectiveness at varying coolant injection rates and slot heights for different hypersonic flow conditions. Results show that film cooling can be an effective way to protect surfaces from high heating in hypersonic laminar flow, with effectiveness increasing at higher coolant injection rates before dropping off further downstream due to mixing. Film cooling provides full protection of the surface for some distance downstream of the slot.
Computational study of film cooling in hypersonic flows
RESEARCH_Zhang Yang_2015
1. Paper Abstracts:
“Experimental Investigation on the Turbine Blade Platform Film Cooling Effected By the Flow Field”
Journal of engineering thermophysics, 2011, Vol.32, No.6 P.941-944
An experimental investigation has been completed using PSP technique to study film cooling on a cooled turbine blade
platform within a linear cascade. The effects of blowing ratio and inlet flow Reynolds number have been investigated and
analyzed. The inlet flow Reynolds number is controlled to be Re=164476、226154、308392 and 359790, while the blowing
ratio of the coolant varies from M=0.4 to1.4. The film cooling holes near the platform leading edge are inclined 45 deg to the
platform surface and the rest are 30 deg. The result indicates that the film cooling effectiveness increases with the blowing
ratio increasing, which is limited to the downstream half of the passage where the platform can be well protected by the
coolant flow. In contrast, the film cooling effectiveness is reduced by increasing the blowing ratio near the leading edge
region where the coolant tends to lift off the surface. The most effective blowing ratio at different inlet Reynolds number
Re=164476、226154、308392、 359790 are M=1.2、1.4、1.4 and 0.8 respectively. When the blowing ratio is fixed, the best
coolant coverage occurs at the largest inlet flow Reynolds number Re=359790.
Fig. 1 Turbine blade cascades
with LEDs
Fig. 2 Film cooling effectiveness distribution with different blowing ratio
(MFR=0.4/left, MFR=1.0, MFR=1.4/right)
“Experimental Investigation about the Effects of Off-deign Condition on the Turbine Vane Endwall Film Cooling”
Annual conference of engineering thermophysics 2010, Nanjing, China, Paper No. 102092
The effects of incidence angle on endwall film cooling in Hp turbine guide vanes were studied in this paper. The influence of
the off-design condition was evaluated by comparison of the experimental data under different incidence angle varying from
i=-15deg to i=+5deg. The film cooling effectiveness on the endwall surface was measured at the blowing ratio from
MFR=0.4 to MFR=1.4. The original airfoil of GE-E3 Hp turbine guide vanes with an enlarging scale of 2.2 was used in the
experiment. The inlet Mach number was Ma=0.1. The PSP (Pressure Sensitive Paint) technique was used to measure the film
cooling effectiveness. A comparative analysis of three groups of incidence angle cases indicated the effects of incidence
angle on endwall film cooling.
The results showed that when the incidence angle was fixed at i=-15deg, i=0deg and i=+5deg respectively, the film cooling
effectiveness increased first, but decreased then (or changed a little) with the blowing ratio increasing. The maximum film
cooling effectiveness was measured at the blowing ratio MFR=1.2, illustrating that the coolant lifted off the surface at higher
blowing ratio. When the blowing ratio was fixed, the endwall film cooling effectiveness decreased with the incidence angle
increasing. The best cooling performance was observed at the incidence angle of i=-15deg. The influence of the cross flow
on the endwall film cooling was obvious at i=+5deg. The cooling effectiveness near the pressure side decreased and then
caused the decrease of film cooling effectiveness on the whole endwall. Through the comparative analysis between the
laterally averaged film cooling effectiveness downstream the second and the third row of holes, a significant phenomenon
was caught that coolant near the second row moved towards the pressure side while the injection moved in the opposite
direction downstream the third row. At all test conditions, the film cooling effectiveness at downstream part of the endwall
was higher than that of the upstream part at all test conditions in the experiment.
2. Fig. 3 Test rig with LEDs Fig. 4 Film cooling effectiveness distribution with different incidence angle
(i=+10deg/left, 0deg, -10deg/right)
“Film Cooling Effectiveness Distribution on First-Stage Vane Endwall With and Without Leading-Edge Fillets Part I:
Effect of Leading Edge Geometry”
ASME Turbo Expo 2011: Power for Land, Sea, and Air, Vancouver, Canada, ASME Paper No.GT2011-45427
The work is focused on the effect of leading edge airfoil geometry on endwall film cooling. Fillets placed at the junctions of
the leading edge and the endwall are used in investigation. Three types of fillet profiles are tested, and the results are
compared with baseline geometry without fillet. The design of the fillet is based on the suggestion by previous literature data
indicating that the sharp fillet is effective in controlling the secondary flow.
Three types of sharp slope fillet with the length to height ratio of 2.8, 1.2 and 0.5 are made using stereo lithography (SLA)
and assessed in the experiment. Distributed with the approximately inviscid flow direction, four rows of compound angle
laidback fan-shaped holes are arranged on the endwall to form full covered coolant film. The four rows of fanshaped holes
are inclined 30 deg to the endwall surface and held an angle of 0, 30, 45 and 60 deg to axial direction respectively. The
fanshaped holes have a lateral diffusion angle of 10 deg from the hole-centreline and a forward expansion angle of 10 deg to
the endwall surface.
The Reynolds number based on the axial chord and inlet velocity of the free-stream flow is 3.5×105
, and the testing is done
in a four-blade cascade with low Mach number condition (0.1 at the inlet) while the blowing ratio of the coolant through the
discrete holes varies from 0.4 to 1.2. The film-cooling effectiveness distributions are obtained using the PSP (pressure
sensitive paint) technique, by which the effect of different fillet geometry on passage induced flow and coolant is shown. The
present paper compares the film cooling effectiveness distributions in a baseline blade cascade with three similar blades with
different leading edge by adding fillets. The results show that with blowing ratio increasing, the film cooling effectiveness
increases on the endwall. For specific blowing ratio, the effects of leading edge geometries could be illustrated as follows.
The baseline geometry provides the best film cooling performance near leading edge pressure side. As for the leading edge
suction side, the best leading edge geometry depends on the blowing ratio. The longfillet is the more effective in controlling
horseshoe vortex at low blowing ratio, but for the high blowing ratio shortfillet and mediumfillet are better.
Fig. 5 NGV cascades with long-fillet
Fig. 6 Film cooling effectiveness distribution on the
endwall with different fillets
“Film Cooling Effectiveness Distribution on First-Stage Vane Endwall With and Without Leading-Edge Fillets Part
II:Effect of Incidence Angle”
ASME Turbo Expo 2011: Power for Land, Sea, and Air, Vancouver, Canada, ASME Paper No.GT2011-45428
3. Using the leading edge airfoil fillet to reduce the aerodynamic loss and surface heat transfer has been proved effective, while
the factor of film cooling has not been considered. The first part of the research indicates that the leading edge fillet could
improve the film cooling effectiveness through controlling the secondary flow, while this conclusion is restricted to the
design condition. The flow field at off-design condition is different from that of the design condition, especially for the
structure of horseshoe vortex at the leading edge. It’s possible that the advantage of fillets is not reliable at positive or
negative inlet flow angle conditions, which makes the investigation on endwall film cooling with leading edge modification
at off-design condition necessary.
This paper, which is the second part of a two-part series research investigating the effects of leading edge modification on
endwall film cooling, is focused on the performance of fillets at off-design condition. The influence of incidence angle on
film cooling effectiveness is studied on first-stage vane endwall with and without leading-edge fillets. A baseline
configuration and three kinds of leading edge airfoil fillets are tested in a low speed four-blade cascade consisting of large
scale model of the GE-E3
Nozzle Guide Vane (NGV). The results show that as the incidence angle varies from i=+10 deg to
i=−10 deg, at low blowing ratio the film cooling effectiveness decreases near the leading edge suction side for all the leading
edge geometries. However, this trend becomes opposite under high blowing ratio that the lowest film cooling effectiveness
condition is at the incidence angle of i=+10 deg.
Near the leading edge pressure side, the film cooling effectiveness increases as the incidence angle varies from i=+10 deg to
i= −10 deg at all blowing ratios in the research. The change of incidence angle causes the peak of laterally averaged
effectiveness in this region to shift upstream. The experimental results also indicate that the longfillet has the lowest
sensitivity towards incidence angle. As for the main passage endwall, with the incidence angle changing form i=+10 deg to
i=-10 deg the averaged film cooling effectiveness increases, while this trend will be eliminated by increasing the blowing
ratio.
Fig. 7 Nozzle guide vane with Short-fillet
Fig. 8 Film cooling effectiveness distribution at
different incidence angle
“Turbine Endwall Film Cooling With Combustor-Turbine Interface Gap Leakage Flow: Effect of Incidence Angle”
10th
International Symposium on Experimental and Computational Aerothermodynamics of Internal Flows - ISAIF10,
Brussels, Belgium, ISAIF Paper No.114
The past research indicates that the combustor-turbine leakage flow could improve the film cooling effectiveness, while this
result is obtained at the design condition. The flow field at off-design condition is different from that of the design condition,
especially for the structure of horseshoe vortex at the leading edge. The change of the passage flow field at off-design
condition will possibly weaken the cooling effectiveness of the combustor-turbine interface gap leakage flow. Near leading
edge area the velocity direction will strongly influence the coolant injection behaviour, which makes it necessary to
investigate the leakage flow cooling performance at off-design conditions.This paper is focused on the performance of
combustor-turbine leakage flow at off-design condition. The influence of incidence angle on film cooling effectiveness is
studied on first-stage vane endwall with combustor-turbine interface slot. A baseline slot configuration is tested in a low
speed four-blade cascade consisting of large scale model of the GE-E3
Nozzle Guide Vane (NGV). The slot has a forward
expansion angle of 30 deg to the endwall surface. The Reynolds number based on the axial chord and inlet velocity of the
free-stream flow is 3.5×105
, and the testing is done in a four-blade cascade with low Mach number condition (0.1 at the inlet)
while the mass flow ratio of the coolant through the interface gap varies from 0.5% to 2.0%. The film-cooling effectiveness
distributions are obtained using the PSP (pressure sensitive paint) technique. The results show that with blowing ratio
increasing, the film cooling effectiveness increases on the endwall. As the incidence angle varies from i=+10 deg to i=-10
deg, at low blowing ratio the film cooling effectiveness decreases near the leading edge suction side. As for the main passage
4. endwall, with the incidence angle changing form i=+10 deg to i=-10 deg the averaged film cooling effectiveness changes
slightly, while this trend will be eliminated by increasing the blowing ratio.
purge Ms=0.5% i= 0deg
ZG
/P
XG
/Cax
-0.2 0 0.2 0.4 0.6 0.8
-1.2
-1
-0.8
-0.6
-0.4
-0.2
0
purge Ms=1.0% i= 0deg
ZG
/P
X
G
/C
ax
-0.2 0 0.2 0.4 0.6 0.8
-1.2
-1
-0.8
-0.6
-0.4
-0.2
0
purge Ms=1.5% i= 0deg
ZG
/P
X
G
/C
ax
-0.2 0 0.2 0.4 0.6 0.8
-1.2
-1
-0.8
-0.6
-0.4
-0.2
0
Fig. 9 NGV cascades with upstream slot
Fig. 10 Film cooling effectiveness distribution with different mass flow
ratio (M=0.5%, 1.0%, 1.5%)
“The Influence of Periodic Unsteady Wakes on Endwall Film Cooling with Combustor-Turbine Interface Gap
Leakage Flow”
International Gas Turbine Congress 2011-IGTC'11, Osaka, Japan, IGTC Paper No.IGTC2011-0126
Using the combustor-turbine leakage flow to prevent the hot gases entering the interface slot has been proved effective, while
the function of the leakage flow as coolant has not been investigated sufficiently, especially under unsteady inflow condition.
In order to close the gap in knowledge concerning the influence of periodic unsteady inflow conditions on the mixing process
of film cooling jets from the combustor-turbine slot, the film cooling effectiveness in a linear large scale high pressure
turbine cascade is measured using Pressure Sensitive Paint (PSP). This paper is focused on the performance of
combustor-turbine leakage flow affected by the upstream periodic wakes. The influence of periodic wakes on film cooling
effectiveness is studied on a first-stage vane endwall with combustor-turbine interface gap.
The periodic impinging wakes are generated by a wake generator consisting of moving bars upstream of the cascade inlet
plane. A baseline slot configuration is tested in a low speed five-blade cascade consisting of large scale model of the LS 89
Nozzle Guide Vane (NGV). The slot has a forward expansion angle of 30 deg to the endwall surface. The Reynolds number
based on the axial chord and exit velocity of the free-stream flow is 6.34×105
, and the testing is performed with low Mach
number condition (0.06 at the inlet) while the mass flow ratio of the coolant through the interface gap varies from 0.3% to
0.7%. The film-cooling effectiveness distributions are obtained using the PSP (pressure sensitive paint) technique. The
results show that with blowing ratio increasing, the film cooling effectiveness increases on the endwall. As the frequency of
the passing wakes varies from 0hz, 25hz to 50hz, the film cooling effectiveness decreases in the main passage endwall,
especially near the leading edge suction side while the difference between low and high frequency condition is not apparent.
purge M=0.3% f=25hz
Z
G
/P
XG
/Cax
-0.19 0.01 0.21 0.41 0.61 0.81 1.0
-1
-0.8
-0.6
-0.4
-0.2
0
purge M=0.3% f=0hz
Z
G
/P
XG
/Cax
-0.19 0.01 0.21 0.41 0.61 0.81 1.0
-1
-0.8
-0.6
-0.4
-0.2
0
Fig. 11 Schematic of the moving bar test rig
Fig. 12 Film cooling effectiveness distribution with and without
upstream periodic wakes
“Endwall Film Cooling with Curving Slot Leakage Flow”
Annual conference of engineering thermophysics 2011, Wuhan, China, Paper No. 112079
To cool the endwall with the combustor-turbine leakage flow has been proved to be feasible, while the search results are
restricted to simple straight slot. The shape of the upstream slot could possibly change the covering skill of the coolant and
5. then influence the endwall film cooling. Considering the injection from a curving combustor-turbine interface gap leakage
might increase the film cooling performance, the research on the cooling characteristics of curving slot is necessary. The
experiment is completed in Hp turbine guide vane cascades. The combustor-turbine interface gap leakage is simulated by the
slots with different figures upstream the endwall.
The test rig consists of four scale-up guide vanes of GE-E3 Hp turbine. The coolant is injected at a 30deg outlet angle from
the endwall surface while the curving slot has bull-nose edge. The film cooling effectiveness is measured using PSP
(Pressure Sensitive Paint) technique with the inlet Reynolds numbers of Re=3.5×105
(based on the axial chord length) and
the inlet Mach number of Ma=0.1. The experimental results indicate that with the mass flow ratio increasing the averaged
film cooling effectiveness on the endwall increases. The film cooling effectiveness near the leading edge suction side drops
as the slot changing from straight to curving one, while the averaged film cooling effectiveness across the entire endwall is
not affected by the slot shape obviously.
Fig. 13 NGV with
upstream slot
Fig. 14 Detail of combustor-turbine interface gap (Strait slot and Curving slot)
“Experimental Investigation of Turbine Phantom Cooling with Combustor-Turbine Leakage Gap Flow” (under
review)
ASME Turbo Expo 2012: Power for Land, Sea, and Air, Copenhagen, Denmark, ASME Paper No.GT2012-69295
The film cooling injection on Hp turbine component surface is strongly affected by the complex flow structure in the nozzle
guide vane or rotor blade passages. The action of passage vortex near endwall surface could dominate the film cooling
effectiveness distribution on the component surfaces. The film cooling injections from endwall and airfoil surface are mixed
by the passage vortex. Considering a small part of the coolant injection from endwall will move towards the airfoil suction
side and then cover some area, the interaction between the coolants injected from endwall and airfoil surface is worth
investigating.
Though the temperature of coolant injection from endwall increases after the mixing process in the main flow, the injections
moving from endwall to airfoil suction side still have the potential of second order cooling. A typical scale-up model of
GE-E3
Hp turbine NGV is used in the experiment to investigate the cooling performance of injection from endwall. Instead
of the endwall itself, the film cooling effectiveness is measured on the airfoil suction side. This paper is focused on the
combustor-turbine interface gap leakage flow moving from endwall to airfoil suction side. The coolant flow is injected at a
30deg angle to the endwall surface. The film cooling holes on the endwall and airfoil surface are not used. The mass flow
ratio and incidence angle are selected to be the parameters in the paper. The experiment is completed with the mass flow ratio
changing from 0.3% to 0.7% and the incidence angle varying from -10deg to +10deg, with inlet Reynolds numbers of
Re=3.5×105
and inlet Mach number of Ma=0.1.
Fig. 15 Cascade painted
by PSP
Fig. 16 Schematic of the PSP
test system
Fig. 17 Sketch map of phantom cooling with
leakage flow
6. “Effect of Incidence Angle on Gas Turbine First-Stage Vane Leading Edge Film Cooling” (under review)
ASME Turbo Expo 2012: Power for Land, Sea, and Air, Copenhagen, Denmark, ASME Paper No.GT2012-69298
The nonuniformity of the Hp turbine inlet flow field put forward higher requirements for NGV (Nozzle Guide Vanes) leading
edge film cooling. The assumption of design condition in most of the experiments couldn’t reflect the true operation
environment in the Hp turbine NGV. The factor of off-design condition was incorporated into the experiment in this research.
The GE-E3
Hp turbine nozzle guide vanes were used in the experiment to investigate the cooling performance of injection
from leading edge with inlet Reynolds numbers of Re=3.5×105
and inlet Mach number of Ma=0.1.
Two different film cooling hole configurations were applied: radial angle fan-shaped holes and compound angle fan-shaped
holes. The cooling characteristics of different hole configurations at off-design condition were analyzed and compared in the
paper. Considering the nonuniformity of the outlet flow field of combustor, incidence angle was selected to be the variable in
the experiment. The predominant vortex in the combustor made the velocity direction in the outlet section difficult to predict.
The position of the stagnation point is strongly affected by the indefinite inlet flow angle, and then in turn changed the
leading edge film cooling effectiveness distribution. The leading edge film cooling performance was assessed with the
incidence angle varying from i=-10deg to i=+10deg. The blowing ratio varying from MFR=0.5 to MFR=1.5, was also
selected as an experimental variable. For the four-row deign, the film holes were located on the leading edge with an
expansion angle of 30deg to the surface and a compound angle of 0deg (baseline configuration) or 10deg. Film cooling
effectiveness distribution was measured using PSP (Pressure Sensitive Paint) technique. The film cooling performance of
radial angle holes and compound angle holes were assessed at both design and off-design conditions. The object of this
research is to change the concept that NGV leading edge film cooling experiment only needs the data at design condition.
Through the comparative analysis of experimental results at different inlet flow angle, the influence of off-design condition
on NGV leading edge film cooling could be illustrated at a reasonable level.
Fig. 18 Nozzle Guide Vanes with leading edge
film cooling
Fig. 19 Leading edge film cooling holes configuration (Radial
angle and Compound angle)
“Turbine Endwall Film Cooling with the Pressure Side Radial Holes”
ASME Turbo Expo 2013: Power for Land, Sea, and Air, San Antonio, Texas, USA, ASME Paper No. GT2013- 95273
One of the key techs of gas turbine performance improvement was to increase the turbine inlet temperature, which has
brought high thermal load to the Nozzle Guide Vanes components. Strong pressure gradient in the NGV and the complex
secondary flow field had made the thermal protection to more challenging. As for the endwall surface near the pressure side
gill region, the relatively higher local pressure and cross flow apparently decreased the film cooling effectiveness. The aim of
this investigation was to evaluate a new design improving the film cooling performance at some cooling blind area with
radial cylindrical holes on the pressure side. The test cascades model was manufactured according to GE-E3
Nozzle Guide
Vanes scaled model,with a scale ratio of 2.2. The experiment was performed under the inlet Mach Number of 0.1 and the
Reynolds Number of 3.5×105
based on the Axial chord Length 78mm. Four rows of staggered radial film cooling holes
were placed at the pressure side gill region. The diameter of the cylindrical holes was 1mm and the length was 5d, with a
hole space of 6d. The span wise angle of the cooling holes was 35 degree and the radial angle was 90 degree. Three blowing
ratios were chosen as the test condition in the experiment, M=0.7, M=1.0 and M=1.3.The film cooling effectiveness was
probed using PSP (Pressure Sensitive Painting) tech and the post processing was performed by the means of mass and heat
transfer analogy.Through the investigation the following results could be achieved: 1)The film cooling effectiveness increase
on the endwall surface near the pressure side gill region, with the highest parameter at Cax=0.3. 2) A double-peak cooled
region develops towards the suction side as the blowing ratio increases. 3)The advantage of the pressure side radial cooling
holes was apparent on the endwall surface near gill region, while the coolant film was weaken obviously along the axial
7. chord at low blowing ratio. The influence of the pressure film cooling could only be detected at the downstream part of the
endwall at higher blowing ratio.
Baseline M=0.7 i= 0degZ/ZP
X/Cax
1
2
3
-0.1 0.1 0.3 0.5 0.7 0.9
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
0 0.2 0.4 0.6
PsCooling M=0.7 i= 0degZ/ZP
X/Cax
1
2
3
-0.1 0.1 0.3 0.5 0.7 0.9
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
0 0.2 0.4 0.6
Fig. 20 The radial cylindrical holes on the pressure side
and the fan shaped holes on the endwall
Fig.21 Film cooling effectiveness distribution on
endwall
(the blowing ratio is 0.7, with and without pressure
side injection)
“Experimental Investigation of Turbine Phantom Cooling on Suction Side with Combustor-Turbine Leakage Gap
Flow And Endwall Film Cooling”
ASME Turbo Expo 2012: Power for Land, Sea, and Air, Copenhagen, Denmark, ASME Paper No. GT2012- 69295
The film cooling injection on Hp turbine component surface is strongly affected by the complex flow structure in the nozzle
guide vane or rotor blade passages. The action of passage vortex near endwall surface could dominate the film cooling
effectiveness distribution on the component surfaces. The film cooling injections from endwall and airfoil surface are mixed
with the passage vortex. Considering a small part of the coolant injection from endwall will move towards the airfoil suction
side and then cover some area, the interaction between the coolants injected from endwall and airfoil surface is worth
investigating. Though the temperature of coolant injection from endwall increases after the mixing process in the main flow,
the injections moving from endwall to airfoil suction side still have the potential of second order cooling. This part of the
coolant is called “Phantom cooling flow” in the paper. A typical scale-up model of GE-E3
Hp turbine NGV is used in the
experiment to investigate the cooling performance of injection from endwall. Instead of the endwall itself, the film cooling
effectiveness is measured on the airfoil suction side. This paper is focused on the combustor-turbine interface gap leakage
flow and the coolant from fan-shaped holes moving from endwall to airfoil suction side. The coolant flow is injected at a
30deg angle to the endwall surface both from a slot and four rows of fan-shaped holes. The film cooling holes on the endwall
and the leakage flow are used simultaneously. The blowing ratio and incidence angle are selected to be the parameters in the
paper. The experiment is completed with the blowing ratio changing from M=0.7 to M=1.3 and the incidence angle varying
from -10deg to +10deg, with inlet Reynolds numbers of Re=3.5×105
and an inlet Mach number of Ma=0.1.
slot M=1.0 i= 0deg
Z/Z
sp
X/Xax
0.45 0.5 0.55 0.6 0.65 0.7
0.6
0.7
0.8
0.9
1
1.1
0
0.1
0.2
0.3
0.4
0.5
slot M=1.3 i= 0deg
Z/Z
sp
X/Xax
0.45 0.5 0.55 0.6 0.65 0.7
0.6
0.7
0.8
0.9
1
1.1
0
0.1
0.2
0.3
0.4
0.5
Fig.22 Film cooling effectiveness distribution on the
suction side at different blowing ratio ( i=0deg )
Fig.23 Film cooling effectiveness distribution on the
suction side at different blowing ratio ( i=0deg )
8. Effect of Incidence Angle on Gas Turbine First-Stage Nozzle Guide Vane Leading Edge And Gill Region Film Cooling
ASME Turbo Expo 2012: Power for Land, Sea, and Air, Copenhagen, Denmark, ASME Paper No. GT2012- 69298
The nonuniformity of the Hp turbine inlet flow field put forward higher requirements for NGV (Nozzle Guide Vanes) leading
edge and gill region film cooling. The assumption of design condition in most of the experiments couldn’t reflect the true
operation environment in the Hp turbine NGV. The factor of off-design condition was incorporated into the experiment in
this research. The GE-E3
Hp turbine nozzle guide vanes were used in the experiment to investigate the cooling performance
of injection from leading edge and gill region with inlet Reynolds numbers of Re=3.5×105
and inlet Mach number of
Ma=0.1. The compound angle fan-shaped film cooling hole configuration was applied.
The cooling characteristics at off-design condition were analyzed and compared in the paper. The leading edge and gill
region film cooling performance was assessed with the incidence angle varying from i=-10deg to i=+10deg. The blowing
ratio varying from M=0.7 to M=1.3, was also selected as an experimental variable. Film cooling effectiveness distribution
was measured using PSP (Pressure Sensitive Paint) technique. The film cooling performance of the compound angle
fan-shaped holes was assessed at both design and off-design conditions. The object of this research is to change the concept
that NGV leading edge film cooling experiment only needs the data at design condition. Through the comparative analysis of
experimental results at different inlet flow angle, the influence of off-design condition on NGV leading edge and gill region
film cooling could be illustrated at a reasonable level.
compound M=0.7 i= 0deg
Z/Z
sp
X/X
ax
0 0.1 0.2 0.3 0.4
0
0.2
0.4
0.6
0.8
1
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
Fig.24 Compound angle film cooling holes configuration
on leading edge and gill region (compared with radial
holes)
Fig.25 Film cooling effectiveness distribution on
leading edge and pressure side (the blowing ratio is 0.7
and the incidence angle is 0deg)
Turbine Endwall Film Cooling With Combustor-Turbine Interface Gap Leakage Flow: Effect of Incidence Angle
Journal of Thermal Science Vol.22, No.2 (2013) 1−10
This paper is focused on the film cooling performance of combustor-turbine leakage flow at off-design condition. The
influence of incidence angle on film cooling effectiveness on first-stage vane endwall with combustor-turbine interface slot is
studied. A baseline slot configuration is tested in a low speed four-blade cascade comprising a large-scale model of the
GE-E3
Nozzle Guide Vane (NGV). The slot has a forward expansion angle of 30 deg to the endwall surface. The Reynolds
number based on the axial chord and inlet velocity of the free-stream flow is 3.5 × 105
and the testing is done in a four-blade
cascade with low Mach number condition (0.1 at the inlet). The blowing ratio of the coolant through the interface gap varies
from M = 0.1 to M = 0.3, while the blowing ratio varies from M = 0.7 to M = 1.3 for the endwall film cooling holes.
The film-cooling effectiveness distributions are obtained using the pressure sensitive paint (PSP) technique. The results show
that with an increasing blowing ratio the film-cooling effectiveness increases on the endwall. As the incidence angle varies
from i = +10 deg to i = -10 deg, at low blowing ratio, the averaged film-cooling effectiveness changes slightly near the
leading edge suction side area. The case of i = +10 deg has better film-cooling performance at the downstream part of this
region where the axial chord is between 0.15 and 0.25. However, the disadvantage of positive incidence appears when the
blowing ratio increases, especially at the upstream part of near suction side region where the axial chord is between 0 and
0.15. On the main passage endwall surface, as the incidence angle changes from i = +10 deg to i = -10 deg, the averaged
film-cooling effectiveness changes slightly and the negative incidence appears to be more effective for the downstream part
film cooling of the endwall surface where the axial chord is between 0.6 and 0.8.
9. slot M=0.7 i= 0degZ/ZP
X/Cax
1
2
3
-0.2 0 0.2 0.4 0.6 0.8
0
0.2
0.4
0.6
0.8
1
1.2 0 0.2 0.4 0.6 0.8
slot M=0.7 i= +10degZ/ZP
X/Cax
1
2
3
-0.2 0 0.2 0.4 0.6 0.8
0
0.2
0.4
0.6
0.8
1
1.2 0 0.2 0.4 0.6 0.8
slot M=0.7 i= -10degZ/ZP
X/Cax
1
2
3
-0.2 0 0.2 0.4 0.6 0.8
0
0.2
0.4
0.6
0.8
1
1.2 0 0.2 0.4 0.6 0.8
Fig.26 Film-cooling effectiveness distribution on the endwall at different incidence angles ( M = 0.7 )
Endwall Film Cooling Using The Staggered Combustor-Turbine Gap Leakage Flow
ASME Turbo Expo 2014: Power for Land, Sea, and Air, Düsseldorf, Germany, ASME Paper No. GT2014-26771
A key technology of gas turbine performance improvement was the increase in the turbine inlet temperature, which brought
high thermal loads to the Nozzle Guide Vane (NGV) components. Strong pressure gradients in the NGVs and the complex
secondary flow field had made thermal protection more challenging. As for the endwall surface near the pressure side gill
region, the relatively higher local pressure and cross flow apparently decreased the film-cooling effectiveness. The aim of
this investigation was to evaluate a new design, improving the film-cooling performance in a cooling blind area with
upstream staggered slot, simulating the combustor-turbine leakage gap flow. The test cascades model was manufactured
according to the GE-E3
nozzle guide vane scaled model,with a scale ratio of 2.2. The experiment was performed under the
inlet Mach number 0.1 and the Reynolds number 3.5×105
based on an axial chord length of 78 mm. The staggered slots
were positioned upstream of the cascades to simulate the combustor-turbine gap leakage. The Pressure Sensitive Painting
(PSP) technique was used to detect the film cooling effectiveness distribution on the endwall surface.
Through the investigation, the following results could be achieved: 1)the film-cooling effectiveness on the endwall surface
downstream the slot and along the pitchwise direction increased, with the highest parameter at Z/Pitch=0.6; 2) a larger cooled
region developed towards the suction side as the blowing ratio increased; 3)the advantage of the staggered slot was apparent
on the endwall surface near the inlet area, while the coolant film was obviously weakened along the axial chord at a low
blowing ratio. The influence of the staggered slots could only be detected in the downstream area of the endwall surface at
the higher blowing ratio.
staggered M=0.7 i= 0degZ/ZP
X/Cax
1
2
3
0 0.2 0.4 0.6 0.8 1
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1 0 0.1 0.2 0.3 0.4
staggered M=1.0 i= 0degZ/ZP
X/Cax
1
2
3
0 0.2 0.4 0.6 0.8 1
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1 0 0.1 0.2 0.3 0.4
staggered M=1.3 i= 0degZ/ZP
X/Cax
1
2
3
0 0.2 0.4 0.6 0.8 1
-0.4
-0.2
0
0.2
0.4
0.6
0.8
1 0 0.1 0.2 0.3 0.4
film-cooling effectiveness distribution on endwall staggered slot injection)
10. Experimental Investigation Of Turbine Phantom Cooling On Endwall With Trailing Edge Discharge Flow
ASME Turbo Expo 2014: Power for Land, Sea, and Air, Düsseldorf, Germany, ASME Paper No. GT2014-26781
The film cooling ejection on High Pressure (Hp) turbine component surface is strongly affected by the complex flow
structure in the nozzle guide vane or rotor blade passages. The action of secondary flow in the main passage could dominate
the film cooling effectiveness distribution on the component surfaces. The film cooling ejections from endwall and airfoil
trailing edge are mixed by the secondary flow. Considering a small part of the coolant ejection from trailing edge discharge
flow will move from the airfoil trailing edge pressure side to endwall downstream and then cover some area, the interaction
between the coolants injected from endwall and airfoil trailing edge is worth investigating.
Though the temperature of coolant discharge flow from trailing edge increases after the mixing process in the internal
cooling procedure, the ejections moving from airfoil to endwall still have the potential of second order cooling. This part of
the coolant is called “Phantom cooling flow” in the paper. A typical scale-up model of Hp turbine NGV is used in the
experiment to investigate the cooling performance of ejection from trailing edge. Instead of the airfoil trailing edge platform
itself, the film cooling effectiveness is measured on the downstream part of the endwall. This paper is focused on the trailing
edge discharge flow with compound angle effects and the coolant from discharge holes moving from trailing edge to endwall
surface.
The coolant flow is injected from the straight discharge holes with a compound angle of 15deg and 45deg respectively. The
film cooling holes on the endwall are used simultaneously to investigate the combined effects. The blowing ratio and
different configurations of compound angle holes are selected to be the changing parameters in the paper. The experiment is
completed with the blowing ratio changing from M=0.7 to M=1.3 and the compound angle is introduced to the entire row of
trailing edge discharge holes (full span), with inlet Reynolds numbers of Re=3.5×105
and an inlet Mach number of Ma=0.1
trailing45 M=1.3 i= 0degZ/ZP
X/C ax
1
2
3
0.9 1 1.1
-0.2
-0.1
0
0 0.2 0.4 0.6
trailing45 M=1.0 i= 0degZ/ZP
X/C ax
1
2
3
0.9 1 1.1
-0.2
-0.1
0
0 0.2 0.4 0.6
trailing45 M=0.7 i= 0degZ/ZP
X/C ax
1
2
3
0.9 1 1.1
-0.2
-0.1
0
0 0.2 0.4 0.6
trailing edge discharge hole configuration (with inner stucture of coolant supply channel)
11. Experimental Investigation On Nonperiodic Endwall Film Cooling In Neighboring Passages with Upstream Rotating
Flow
ASME Turbo Expo 2014: Power for Land, Sea, and Air, Düsseldorf, Germany, ASME Paper No. GT2014-26824
The distribution of film-cooling holes is considered to be the same between neighboring high pressure turbine passages in
most cascade experiments. Because of the difference in accounts of combustors and vanes, however, the flow fields of
neighboring passages are completely different. The secondary flow, especially the passage vortex, is dominated by the
upstream inlet rotating flow whose relative flow direction is the reverse between the neighboring vane passages. Specific
rotating directions introduce new challenges in film-cooling design. The present experiment compares three groups of
endwall film-cooling with anticlockwise rotating flow inlets at different clocking positions, and the film-cooling effect is
analysed to investigate the effects of inlet rotating flow. The inlet flow condition of neighboring passages is simulated by
switching the position of the swirler by means of which rotating inlet flow conditions in different positions are achieved.
The GE-E3
airfoil is used in the cascades, with a scaled-up factor of 2.2. The inlet Reynolds number is 3.5×105
and the Mach
number is 0.1. The effects of the blowing ratio and relative positions of the swirler are investigated in the experiment.
Adiabatic film-cooling effectiveness is probed by using pressure-sensitive painting (PSP). The coolant is simulated by
nitrogen by which a density ratio of around 1.0 can be achieved. Fan-shaped film-cooling holes are introduced into the
endwall surface as well as trailing edge discharge holes. The cooling performance of the combustor-turbine gap leakage flow
is also considered simultaneously.
Conclusions are as follows: (1) the anticlockwise direction of rotating flow influences the endwall film-cooling effectiveness,
especially for the upstream part of the endwall which is mainly covered by the leakage flow; (2) the film-cooling
effectiveness in the neighbouring passages differs depending on the position of the inlet rotating flow core; (3) the
film-cooling performance at the downstream part of the endwall is partly influenced by the upstream rotating flow inlet as
well.
the positions of swirler and the configuration of endwall inlet slot (with inner stucture of coolant supply channel)