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IRJET- Computational Fluid Dynamic Analysis of Performance of Centrifugal Pum...IRJET Journal
This document describes a computational fluid dynamics (CFD) analysis of the performance of a centrifugal pump impeller on a cooling system. The study analyzes the design and performance of a centrifugal pump by changing the impeller blade angle using CFD software. The objectives are to perform CFD analysis of the impeller, study the effect of changing the impeller blade angle, develop an impeller design approach, optimize the design, and validate it through experiment and simulation. Various impeller blade angle combinations are simulated and the resulting pressures are recorded and analyzed. The results show how discharge is highly affected by flow velocity and how pressure varies for different impeller blade angles.
The document summarizes various statistical data analysis and engineering projects undertaken by the author. It includes analysis of supplier performance using KPIs and charts, manpower planning through part number trend analysis, creation of quality inspection documents, research on material handling systems, design of a solar powered car including CAD modeling and CFD simulation, CFD analysis of boundary layer flow over wings and turbine blades, turbomachinery design including preliminary design of an axial turbine and turbofan engine, as well as other projects involving numerical analysis, lightweight structure design, and computational welding analysis.
Dynamic Modeling and Simulation on GE90 Enginetheijes
1) A dynamic model of the GE90 turbofan engine was developed using MATLAB/Simulink software to simulate engine performance and predict on-design characteristics.
2) The model includes components like the fan, compressors, combustor, turbines and nozzle. Transient behavior was modeled using plenum volumes and shaft inertias.
3) Simulation results for various parameters like pressures, temperatures, mass flows and thrust were obtained. Comparisons to GE test data showed good agreement within around 5-10% error, validating the dynamic model.
This document summarizes an optimization study to maximize the power output of a ducted vertical axis wind turbine. The study uses computational fluid dynamics (CFD) simulations coupled with a genetic algorithm to optimize the geometry of the duct surrounding the turbine. The duct geometry is defined by 7 curvature points and optimized at 3 positions relative to the turbine center. The optimized duct configuration resulted in a 20° convergence angle with the throat at the turbine center. This optimized duct increased the tip speed ratio and power coefficient at maximum power output and decreased the torque ripple factor compared to an un-ducted turbine.
FLUID FLOW ANALYSIS OF CENTRIFUGAL FAN BY USING FEMIAEME Publication
This document presents a study analyzing the fluid flow of a centrifugal fan using finite element analysis (FEA). The study aims to compare experimental results with simulation results from ANSYS Fluent. The geometry of a forward backward curved centrifugal fan with 630mm diameter is modeled and meshed. Boundary conditions from experimental data are applied. Fluent simulations are run to obtain pressure distributions and flow patterns. Results for static pressure, efficiency, and power are compared to experimental values, showing deviations within 10-15%. The authors conclude CFD analysis can accurately validate experimental fan performance analysis when optimizing aspects like volute casing design.
Modified CSKA Application in the Floating Point Adder using Carry Skip Adder ...IJMTST Journal
In this paper, we present a carry skip adder (CSKA) structure that has a higher speed yet lower energy
consumption compared with the conventional one. The speed enhancement is achieved by applying
concatenation and incrementation schemes to improve the efficiency of the conventional CSKA (Conv
CSKA) structure. In addition, instead of utilizing multiplexer logic, the proposed structure makes use of
AND-OR-Invert (AOI) and OR-AND-Invert (OAI) compound gates for the skip logic. The structure maybe
realized with both fixed stage size and variable stage size styles, wherein the latter further improves the
speed and energy parameters of the adder. Finally, a hybrid variable latency extension of the proposed
structure, which lowers the power consumption without considerably impacting the speed, is presented.
This extension utilizes a modified parallel structure for increasing the slack time, and hence, enabling
further voltage reduction. The proposed structures are assessed by comparing their speed, power, and
energy parameters with those of other adders using a 45-nmstatic CMOS technology for a wide range of
supply voltages. The results that are obtained using HSPICE simulations reveal, on average, 44% and
38%improvements in the delay and energy, respectively, compared with those of the Conv-CSKA. In
addition, the power–delay product was the lowest among the structures considered in this paper, while its
energy–delay product was almost the same as that of the Kogge–Stone parallel prefix adder with
considerably smaller area and power consumption. Simulations on the proposed hybrid variable latency
CSKA reveal reduction in the power consumption compared with the latest works in this field while having
a reasonably high speed.
This document describes a study that used multi-objective optimization to improve the efficiency of centrifugal pump impellers. The study used computational fluid dynamics simulations and genetic algorithms to optimize impeller blade designs. Two application examples were considered. The first optimized a design with 14 parameters and achieved a 2% efficiency improvement over the baseline design. The second optimized a design with 8 parameters and achieved a 1% efficiency gain and 2m head increase. Overall, the multi-objective optimization approach was able to produce designs with better efficiency and head characteristics than the baseline designs.
This document summarizes the design of the Jayhawk Economic Turboprop Transport (J.E.T.T.) aircraft for the 2013-2014 AIAA Undergraduate Team Aircraft Design Competition. It provides the mission specifications for a new regional turboprop airliner, including a 400 nautical mile economic mission carrying 75 passengers and a 1,600 nautical mile design mission carrying 67 passengers. It then describes the initial configurations considered and presents analysis on determining design parameters through statistical modeling techniques. Key aspects of the preliminary aircraft design are summarized, including engine selection, wing design, and layout of major systems.
IRJET- Computational Fluid Dynamic Analysis of Performance of Centrifugal Pum...IRJET Journal
This document describes a computational fluid dynamics (CFD) analysis of the performance of a centrifugal pump impeller on a cooling system. The study analyzes the design and performance of a centrifugal pump by changing the impeller blade angle using CFD software. The objectives are to perform CFD analysis of the impeller, study the effect of changing the impeller blade angle, develop an impeller design approach, optimize the design, and validate it through experiment and simulation. Various impeller blade angle combinations are simulated and the resulting pressures are recorded and analyzed. The results show how discharge is highly affected by flow velocity and how pressure varies for different impeller blade angles.
The document summarizes various statistical data analysis and engineering projects undertaken by the author. It includes analysis of supplier performance using KPIs and charts, manpower planning through part number trend analysis, creation of quality inspection documents, research on material handling systems, design of a solar powered car including CAD modeling and CFD simulation, CFD analysis of boundary layer flow over wings and turbine blades, turbomachinery design including preliminary design of an axial turbine and turbofan engine, as well as other projects involving numerical analysis, lightweight structure design, and computational welding analysis.
Dynamic Modeling and Simulation on GE90 Enginetheijes
1) A dynamic model of the GE90 turbofan engine was developed using MATLAB/Simulink software to simulate engine performance and predict on-design characteristics.
2) The model includes components like the fan, compressors, combustor, turbines and nozzle. Transient behavior was modeled using plenum volumes and shaft inertias.
3) Simulation results for various parameters like pressures, temperatures, mass flows and thrust were obtained. Comparisons to GE test data showed good agreement within around 5-10% error, validating the dynamic model.
This document summarizes an optimization study to maximize the power output of a ducted vertical axis wind turbine. The study uses computational fluid dynamics (CFD) simulations coupled with a genetic algorithm to optimize the geometry of the duct surrounding the turbine. The duct geometry is defined by 7 curvature points and optimized at 3 positions relative to the turbine center. The optimized duct configuration resulted in a 20° convergence angle with the throat at the turbine center. This optimized duct increased the tip speed ratio and power coefficient at maximum power output and decreased the torque ripple factor compared to an un-ducted turbine.
FLUID FLOW ANALYSIS OF CENTRIFUGAL FAN BY USING FEMIAEME Publication
This document presents a study analyzing the fluid flow of a centrifugal fan using finite element analysis (FEA). The study aims to compare experimental results with simulation results from ANSYS Fluent. The geometry of a forward backward curved centrifugal fan with 630mm diameter is modeled and meshed. Boundary conditions from experimental data are applied. Fluent simulations are run to obtain pressure distributions and flow patterns. Results for static pressure, efficiency, and power are compared to experimental values, showing deviations within 10-15%. The authors conclude CFD analysis can accurately validate experimental fan performance analysis when optimizing aspects like volute casing design.
Modified CSKA Application in the Floating Point Adder using Carry Skip Adder ...IJMTST Journal
In this paper, we present a carry skip adder (CSKA) structure that has a higher speed yet lower energy
consumption compared with the conventional one. The speed enhancement is achieved by applying
concatenation and incrementation schemes to improve the efficiency of the conventional CSKA (Conv
CSKA) structure. In addition, instead of utilizing multiplexer logic, the proposed structure makes use of
AND-OR-Invert (AOI) and OR-AND-Invert (OAI) compound gates for the skip logic. The structure maybe
realized with both fixed stage size and variable stage size styles, wherein the latter further improves the
speed and energy parameters of the adder. Finally, a hybrid variable latency extension of the proposed
structure, which lowers the power consumption without considerably impacting the speed, is presented.
This extension utilizes a modified parallel structure for increasing the slack time, and hence, enabling
further voltage reduction. The proposed structures are assessed by comparing their speed, power, and
energy parameters with those of other adders using a 45-nmstatic CMOS technology for a wide range of
supply voltages. The results that are obtained using HSPICE simulations reveal, on average, 44% and
38%improvements in the delay and energy, respectively, compared with those of the Conv-CSKA. In
addition, the power–delay product was the lowest among the structures considered in this paper, while its
energy–delay product was almost the same as that of the Kogge–Stone parallel prefix adder with
considerably smaller area and power consumption. Simulations on the proposed hybrid variable latency
CSKA reveal reduction in the power consumption compared with the latest works in this field while having
a reasonably high speed.
This document describes a study that used multi-objective optimization to improve the efficiency of centrifugal pump impellers. The study used computational fluid dynamics simulations and genetic algorithms to optimize impeller blade designs. Two application examples were considered. The first optimized a design with 14 parameters and achieved a 2% efficiency improvement over the baseline design. The second optimized a design with 8 parameters and achieved a 1% efficiency gain and 2m head increase. Overall, the multi-objective optimization approach was able to produce designs with better efficiency and head characteristics than the baseline designs.
This document summarizes the design of the Jayhawk Economic Turboprop Transport (J.E.T.T.) aircraft for the 2013-2014 AIAA Undergraduate Team Aircraft Design Competition. It provides the mission specifications for a new regional turboprop airliner, including a 400 nautical mile economic mission carrying 75 passengers and a 1,600 nautical mile design mission carrying 67 passengers. It then describes the initial configurations considered and presents analysis on determining design parameters through statistical modeling techniques. Key aspects of the preliminary aircraft design are summarized, including engine selection, wing design, and layout of major systems.
Improving Efficiency of Submersible Pump Impeller of Mixed Flow Type by Desig...IRJET Journal
This document describes a study to improve the efficiency of a mixed flow pump impeller through design modifications and computational fluid dynamics (CFD) analysis. The existing impeller data is presented and objectives are defined to analytically design a new improved efficiency impeller using ANSYS software. The new impeller is modeled and analyzed using CFD. Results show the new design increases head from 8.12 m/stage to 9.60 m/stage and hydraulic efficiency from 67.1% to 93.68% compared to the existing design, demonstrating the improved performance achieved through design modifications and CFD analysis.
Turbofan Engine Modelling and Control Design using Linear Quadratic Regulator...theijes
There are many applications in which gas turbine engine is used today, including aircraft propulsion for both commercial and military purposes, and power generation and in all these Control systems technology has played a fundamental role in enhancing performance. Modelling plays a significant role in the development of the entire engine system performance. This paper investigated Linear Quadratic Regulator (LQR) model-based control method to obtain estimates of performance parameters. The main control variable selected is the fuel flow to control the rotational speed of high-pressure spool speed of the turbofan engine. Firstly a suitable mathematical model of the engine is developed in MATLAB Simulink environment with both the intercomponent volume and the constant mass flow methods used. Equations of the mass flow rate and the torque balance are incorporated in the steady state and dynamic state of the thermodynamic engine model. This represents the engine model by a set of first-order differential and algebraic equations and a linearized model is extracted for the analysis and design of a controller by LQR. It is demonstrated that LQR based controllers can perform better than conventional PID controllers. The settling time, rise time and maximum overshoot for LQR based controller are all less than those for PID based controller. The input also changes more accurately for LQR than the PID controller compared.
Development of Software for Sizing of Axial Flow Fans -- Zeus NumerixAbhishek Jain
Above Research Paper can be downloaded from www.zeusnumerix.com
The research paper aims to showcase the development of software for the aerodynamic design of cooling tower fans. The software inputs requirements from the user and outputs the 3D CAD of an optimized fan. The software calculates power consumption, efficiency, torque, and sound level of the fan. The software has been found to overpredict the performance by few percentage points due to uncertainty in manufacturing. Authors - Abhishek Jain (Zeus Numerix), Ketan Bhokray (IIT Bombay)
The document discusses thermodynamic optimization of screw compressors. It describes using a numerical model of fluid flow and thermodynamic processes combined with a rotor profile generation algorithm to optimize a screw compressor design for a given application and fluid. Some key points:
- The optimization considers variables like rotor profile, compressor speed, oil flow rate, temperature to maximize efficiency and minimize size depending on the compressed gas/vapor and whether the compressor is oil-free or oil-flooded.
- A constrained simplex method called the Box complex method is used to find local minima which are then used to estimate a global minimum.
- The numerical model solves conservation equations for properties like internal energy and mass flow using a Runge
PERFORMANCES EVALUATION AND BLADE NUMBER OPTIMIZATION OF RADIAL INFLOW TURBINEIAEME Publication
The energy exhaust recovery in engines is obtained using turbochargers which are widely used in the automotive industry. A turbocharged engine leads to a better overall system efficiency and a reduction in exhaust emissions compared, at constant power, with a naturally aspirated engine. The numerical approach in the present work is to explore ways of improving the performances of the radial inflow turbine. This work investigates the performances of a radial inflow turbine under steady states conditions and how they are affected by the rotor geometry. The radial inflow turbine is investigated numerically using 3D Reynolds averaged Navier-Stokes equations, the objective hear is to determine the optimum of performance characteristics of the turbine. The building of the geometry and the generation of unstructured meshes are achieved using ANSYS-ICEM software whereas in order to simulate the flow, the ANSYS-CFX code is applied. The numerical method is also used to determine optimum geometrical characteristics such as the optimum of blade number. It has been found that the rotor with 12 blades gives better performances.
Piping models are directly represented in structural models to account for their weight and surface area. Only basic loads for pressure, temperature, weight, wind and blast are required from pipe stress analysis and developed in the structural model using piping models derived from neutral files. Piping and supports are physically significant compared to main structures, so piping models are directly included in structural analyses.
IRJET- Thermodynamic Analysis and Optimization of Offset Strip Fin Plate ...IRJET Journal
This document discusses the thermodynamic analysis and optimization of an offset strip fin plate heat exchanger. The analysis is conducted using MATLAB to evaluate parameters like heat transfer coefficient, pressure drop, Colburn factor, and friction factor. Design of experiments is used to optimize the heat exchanger design by reducing the number of simulation runs. Key parameters varied include fin spacing, height, thickness, length, and operating parameters like frontal air velocity and Reynolds number. The results show that increasing parameters like the ratio of fin spacing to height (alpha) reduces heat transfer and pressure drop. The goal of the optimization is to determine the set of parameters that provide the best balance between high heat transfer and low pressure drop.
An approach to evaluate the heat exchanger retrofit for installed industrial ...eSAT Journals
This document summarizes an economic evaluation of retrofitting heat exchangers to existing industrial gas turbines to improve their efficiency. It describes using the net present value method to compare the economics of simple cycle and recuperative cycle configurations for two gas turbine models. The analysis found that retrofitting heat exchangers can increase the net present value over the simple cycle, with differences ranging from $11 million to over $46 million depending on the turbine model and assumptions. However, the payback period for the retrofit may be longer, and the analysis also examined the effects of utilization rate and other factors on the economic viability.
The document describes how simulation, wind tunnel testing, and road tests are used complementarily during the aerodynamic development of a new BMW SUV. Simulation is used early on to assess styling themes when only basic vehicle geometry is available. More detailed models are later tested in wind tunnels to evaluate underhood flow and component temperatures. Road tests evaluate real-world issues like soiling and snow deposition that other methods cannot fully replicate. Each tool has advantages and limitations, so clever application at the right time helps shorten development cost and time.
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
CFD Analysis on an Atmospheric Re-Entry ModuleIRJET Journal
1) The document describes a CFD analysis of the aerodynamic heating and flow field around the Apollo AS-202 atmospheric re-entry module.
2) The analysis uses computational fluid dynamics to obtain the velocity profile, temperature, pressure, and heat flux distributions at various locations on the capsule during re-entry.
3) The results are compared to flight data from the AS-202 mission to evaluate the CFD model's ability to accurately model the aerothermodynamic environment experienced by the capsule during atmospheric re-entry.
Air flow and charge motion study of engine intake portTunAnh309
1) A study was conducted using CFD to simulate experimental flow bench tests of an engine intake port design. CFD simulations were run at different valve lifts to calculate air flow rate and emulate the flow bench.
2) Flow coefficient and swirl ratio results from CFD showed good agreement with experimental flow bench measurements, though CFD overpredicted swirl ratio, especially at lower lifts.
3) CFD provides additional insight into flow patterns and velocities not obtainable from flow bench testing alone, allowing designers to more efficiently evaluate intake port designs.
Qblade an open source tool for design and simulation Phuong Dx
The software QBlade is an open source tool for designing and simulating horizontal axis and vertical axis wind turbines. It utilizes the Blade Element Momentum method for horizontal axis wind turbines and the Double Multiple Streamtube method for vertical axis wind turbines. QBlade integrates the airfoil analysis code XFOIL to compute airfoil lift and drag coefficients, and includes a module to extrapolate these coefficients to 360 degrees of attack. QBlade allows users to design wind turbine blades, optimize blade twist and chord distributions, define turbine properties, and simulate turbine performance and energy production. The goal of QBlade is to provide a comprehensive open source tool for wind turbine design and analysis.
This document summarizes a study that used computational fluid dynamics (CFD) software to analyze air flow in a two-pass smooth square channel with a 180-degree turn. Simulations were performed using Gambit and Fluent software at Reynolds numbers from 10,000 to 60,000. Results for mass flow rate and heat transfer rate were compared to experimental data. Turbulence models like k-ε, k-ω, and Reynolds stress were used to simulate turbulent flow conditions.
This presentation outlines plans to redesign an existing pump configuration to increase reliability. The customer wants to upgrade the pumps to increase capacity from 4 x 25% to 4 x 50%. The engineering contractor will deliver 3D scans and models of the current and new setups in a greenfield site to move the pumps. The new design must consider safety, accessibility, and maintaining production during construction. The schedule includes completing the 3D model by the end of January 2015 and finalizing the design in February and March.
This master's thesis investigates highly loaded transonic fans through aerodynamic and aeroelastic simulations using ANSYS and ABAQUS. It consists of two parts: the first validates simulation results like modal and stress analysis against experimental data from a NASA technical paper on a two-stage fan. The second part of the thesis, under the FanTip project sponsored by German government agencies, aims to optimize jet engine fan design through aeroelastic simulations verified by wind tunnel tests, applying a traveling wave mode approach to determine flutter using ANSYS CFX and Calculix. Simulation results for the fan, outlet guide vanes, and engine blades are also compared to fan performance curves.
The document proposes designing and building a car-mounted thrust stand for dynamic testing of propellers as an alternative to traditional wind tunnel testing. Key details include:
- The setup would allow testing of propellers over 10 inches in diameter, which most universities cannot test in wind tunnels.
- Aerodynamic considerations require the propeller to be at least 5 times its diameter from the car roof to avoid blockage, and the largest propeller to be tested is 10 inches so the minimum height is set at 27 inches.
- Structural analysis shows the design has a safety factor of at least 1.6 under worst-case loads to remain safely attached to the car at high speeds.
This document describes a CFD analysis of fluid flow through tube banks in heat recovery steam generators (HRSGs). The authors developed a new procedure to define porous medium parameters like loss coefficients starting from 3D simulations of flow through tube banks. Both finned and bare tube banks were considered. The analysis was performed using the commercial CFD code Fluent to simulate flow through a single tube row and investigate the effects of Reynolds number, inlet yaw angle, and inlet pitch angle on pressure drop and outlet flow angles. Results were compared to experimental data for a real fired HRSG to validate the proposed porous media modeling approach.
This document summarizes a research paper that proposes using parallel concatenated turbo codes in wireless sensor networks in an adaptive way. The key points are:
1) Turbo codes can achieve near-Shannon limit performance but decoding is complex, making them difficult to implement on energy-constrained sensor nodes.
2) The proposed approach shifts the complex turbo decoding to the base station while sensor nodes implement encoding and basic error correction.
3) At sensor nodes, a parallel concatenated convolutional code (PCCC) circuit encodes data and detects/corrects errors in forwarded packets. This improves energy efficiency and reliability over the wireless sensor network.
This document discusses using discrete event simulation to increase productivity in digital manufacturing. It describes using Tecnomatix Plant Simulation software integrated with a graphical user interface created in Visual Basic and an Oracle database. A simulation model of a manufacturing system with 4 shops, 18 machines, 10 families and 40 parts is created. Processing and setup times are generated using Erlang distributions and stored in the Oracle database. The integration of these tools allows for collaborative modeling and analysis to optimize manufacturing systems.
IJERD(www.ijerd.com)International Journal of Engineering Research and Develop...IJERD Editor
This document summarizes a research paper that proposes a new methodology for reducing additive distortion in steganography. The paper introduces a method to embed 2 bits of information in a pixel by altering only one bit plane. This is expected to make detection of covert communication more difficult for steganalysis algorithms compared to altering the least significant bit. The method uses Java for implementation and MATLAB to analyze histograms of original and stego images. Experimental results on embedding secret text in images are presented, along with analysis of the distortion levels and security of the proposed approach.
Improving Efficiency of Submersible Pump Impeller of Mixed Flow Type by Desig...IRJET Journal
This document describes a study to improve the efficiency of a mixed flow pump impeller through design modifications and computational fluid dynamics (CFD) analysis. The existing impeller data is presented and objectives are defined to analytically design a new improved efficiency impeller using ANSYS software. The new impeller is modeled and analyzed using CFD. Results show the new design increases head from 8.12 m/stage to 9.60 m/stage and hydraulic efficiency from 67.1% to 93.68% compared to the existing design, demonstrating the improved performance achieved through design modifications and CFD analysis.
Turbofan Engine Modelling and Control Design using Linear Quadratic Regulator...theijes
There are many applications in which gas turbine engine is used today, including aircraft propulsion for both commercial and military purposes, and power generation and in all these Control systems technology has played a fundamental role in enhancing performance. Modelling plays a significant role in the development of the entire engine system performance. This paper investigated Linear Quadratic Regulator (LQR) model-based control method to obtain estimates of performance parameters. The main control variable selected is the fuel flow to control the rotational speed of high-pressure spool speed of the turbofan engine. Firstly a suitable mathematical model of the engine is developed in MATLAB Simulink environment with both the intercomponent volume and the constant mass flow methods used. Equations of the mass flow rate and the torque balance are incorporated in the steady state and dynamic state of the thermodynamic engine model. This represents the engine model by a set of first-order differential and algebraic equations and a linearized model is extracted for the analysis and design of a controller by LQR. It is demonstrated that LQR based controllers can perform better than conventional PID controllers. The settling time, rise time and maximum overshoot for LQR based controller are all less than those for PID based controller. The input also changes more accurately for LQR than the PID controller compared.
Development of Software for Sizing of Axial Flow Fans -- Zeus NumerixAbhishek Jain
Above Research Paper can be downloaded from www.zeusnumerix.com
The research paper aims to showcase the development of software for the aerodynamic design of cooling tower fans. The software inputs requirements from the user and outputs the 3D CAD of an optimized fan. The software calculates power consumption, efficiency, torque, and sound level of the fan. The software has been found to overpredict the performance by few percentage points due to uncertainty in manufacturing. Authors - Abhishek Jain (Zeus Numerix), Ketan Bhokray (IIT Bombay)
The document discusses thermodynamic optimization of screw compressors. It describes using a numerical model of fluid flow and thermodynamic processes combined with a rotor profile generation algorithm to optimize a screw compressor design for a given application and fluid. Some key points:
- The optimization considers variables like rotor profile, compressor speed, oil flow rate, temperature to maximize efficiency and minimize size depending on the compressed gas/vapor and whether the compressor is oil-free or oil-flooded.
- A constrained simplex method called the Box complex method is used to find local minima which are then used to estimate a global minimum.
- The numerical model solves conservation equations for properties like internal energy and mass flow using a Runge
PERFORMANCES EVALUATION AND BLADE NUMBER OPTIMIZATION OF RADIAL INFLOW TURBINEIAEME Publication
The energy exhaust recovery in engines is obtained using turbochargers which are widely used in the automotive industry. A turbocharged engine leads to a better overall system efficiency and a reduction in exhaust emissions compared, at constant power, with a naturally aspirated engine. The numerical approach in the present work is to explore ways of improving the performances of the radial inflow turbine. This work investigates the performances of a radial inflow turbine under steady states conditions and how they are affected by the rotor geometry. The radial inflow turbine is investigated numerically using 3D Reynolds averaged Navier-Stokes equations, the objective hear is to determine the optimum of performance characteristics of the turbine. The building of the geometry and the generation of unstructured meshes are achieved using ANSYS-ICEM software whereas in order to simulate the flow, the ANSYS-CFX code is applied. The numerical method is also used to determine optimum geometrical characteristics such as the optimum of blade number. It has been found that the rotor with 12 blades gives better performances.
Piping models are directly represented in structural models to account for their weight and surface area. Only basic loads for pressure, temperature, weight, wind and blast are required from pipe stress analysis and developed in the structural model using piping models derived from neutral files. Piping and supports are physically significant compared to main structures, so piping models are directly included in structural analyses.
IRJET- Thermodynamic Analysis and Optimization of Offset Strip Fin Plate ...IRJET Journal
This document discusses the thermodynamic analysis and optimization of an offset strip fin plate heat exchanger. The analysis is conducted using MATLAB to evaluate parameters like heat transfer coefficient, pressure drop, Colburn factor, and friction factor. Design of experiments is used to optimize the heat exchanger design by reducing the number of simulation runs. Key parameters varied include fin spacing, height, thickness, length, and operating parameters like frontal air velocity and Reynolds number. The results show that increasing parameters like the ratio of fin spacing to height (alpha) reduces heat transfer and pressure drop. The goal of the optimization is to determine the set of parameters that provide the best balance between high heat transfer and low pressure drop.
An approach to evaluate the heat exchanger retrofit for installed industrial ...eSAT Journals
This document summarizes an economic evaluation of retrofitting heat exchangers to existing industrial gas turbines to improve their efficiency. It describes using the net present value method to compare the economics of simple cycle and recuperative cycle configurations for two gas turbine models. The analysis found that retrofitting heat exchangers can increase the net present value over the simple cycle, with differences ranging from $11 million to over $46 million depending on the turbine model and assumptions. However, the payback period for the retrofit may be longer, and the analysis also examined the effects of utilization rate and other factors on the economic viability.
The document describes how simulation, wind tunnel testing, and road tests are used complementarily during the aerodynamic development of a new BMW SUV. Simulation is used early on to assess styling themes when only basic vehicle geometry is available. More detailed models are later tested in wind tunnels to evaluate underhood flow and component temperatures. Road tests evaluate real-world issues like soiling and snow deposition that other methods cannot fully replicate. Each tool has advantages and limitations, so clever application at the right time helps shorten development cost and time.
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
CFD Analysis on an Atmospheric Re-Entry ModuleIRJET Journal
1) The document describes a CFD analysis of the aerodynamic heating and flow field around the Apollo AS-202 atmospheric re-entry module.
2) The analysis uses computational fluid dynamics to obtain the velocity profile, temperature, pressure, and heat flux distributions at various locations on the capsule during re-entry.
3) The results are compared to flight data from the AS-202 mission to evaluate the CFD model's ability to accurately model the aerothermodynamic environment experienced by the capsule during atmospheric re-entry.
Air flow and charge motion study of engine intake portTunAnh309
1) A study was conducted using CFD to simulate experimental flow bench tests of an engine intake port design. CFD simulations were run at different valve lifts to calculate air flow rate and emulate the flow bench.
2) Flow coefficient and swirl ratio results from CFD showed good agreement with experimental flow bench measurements, though CFD overpredicted swirl ratio, especially at lower lifts.
3) CFD provides additional insight into flow patterns and velocities not obtainable from flow bench testing alone, allowing designers to more efficiently evaluate intake port designs.
Qblade an open source tool for design and simulation Phuong Dx
The software QBlade is an open source tool for designing and simulating horizontal axis and vertical axis wind turbines. It utilizes the Blade Element Momentum method for horizontal axis wind turbines and the Double Multiple Streamtube method for vertical axis wind turbines. QBlade integrates the airfoil analysis code XFOIL to compute airfoil lift and drag coefficients, and includes a module to extrapolate these coefficients to 360 degrees of attack. QBlade allows users to design wind turbine blades, optimize blade twist and chord distributions, define turbine properties, and simulate turbine performance and energy production. The goal of QBlade is to provide a comprehensive open source tool for wind turbine design and analysis.
This document summarizes a study that used computational fluid dynamics (CFD) software to analyze air flow in a two-pass smooth square channel with a 180-degree turn. Simulations were performed using Gambit and Fluent software at Reynolds numbers from 10,000 to 60,000. Results for mass flow rate and heat transfer rate were compared to experimental data. Turbulence models like k-ε, k-ω, and Reynolds stress were used to simulate turbulent flow conditions.
This presentation outlines plans to redesign an existing pump configuration to increase reliability. The customer wants to upgrade the pumps to increase capacity from 4 x 25% to 4 x 50%. The engineering contractor will deliver 3D scans and models of the current and new setups in a greenfield site to move the pumps. The new design must consider safety, accessibility, and maintaining production during construction. The schedule includes completing the 3D model by the end of January 2015 and finalizing the design in February and March.
This master's thesis investigates highly loaded transonic fans through aerodynamic and aeroelastic simulations using ANSYS and ABAQUS. It consists of two parts: the first validates simulation results like modal and stress analysis against experimental data from a NASA technical paper on a two-stage fan. The second part of the thesis, under the FanTip project sponsored by German government agencies, aims to optimize jet engine fan design through aeroelastic simulations verified by wind tunnel tests, applying a traveling wave mode approach to determine flutter using ANSYS CFX and Calculix. Simulation results for the fan, outlet guide vanes, and engine blades are also compared to fan performance curves.
The document proposes designing and building a car-mounted thrust stand for dynamic testing of propellers as an alternative to traditional wind tunnel testing. Key details include:
- The setup would allow testing of propellers over 10 inches in diameter, which most universities cannot test in wind tunnels.
- Aerodynamic considerations require the propeller to be at least 5 times its diameter from the car roof to avoid blockage, and the largest propeller to be tested is 10 inches so the minimum height is set at 27 inches.
- Structural analysis shows the design has a safety factor of at least 1.6 under worst-case loads to remain safely attached to the car at high speeds.
This document describes a CFD analysis of fluid flow through tube banks in heat recovery steam generators (HRSGs). The authors developed a new procedure to define porous medium parameters like loss coefficients starting from 3D simulations of flow through tube banks. Both finned and bare tube banks were considered. The analysis was performed using the commercial CFD code Fluent to simulate flow through a single tube row and investigate the effects of Reynolds number, inlet yaw angle, and inlet pitch angle on pressure drop and outlet flow angles. Results were compared to experimental data for a real fired HRSG to validate the proposed porous media modeling approach.
This document summarizes a research paper that proposes using parallel concatenated turbo codes in wireless sensor networks in an adaptive way. The key points are:
1) Turbo codes can achieve near-Shannon limit performance but decoding is complex, making them difficult to implement on energy-constrained sensor nodes.
2) The proposed approach shifts the complex turbo decoding to the base station while sensor nodes implement encoding and basic error correction.
3) At sensor nodes, a parallel concatenated convolutional code (PCCC) circuit encodes data and detects/corrects errors in forwarded packets. This improves energy efficiency and reliability over the wireless sensor network.
This document discusses using discrete event simulation to increase productivity in digital manufacturing. It describes using Tecnomatix Plant Simulation software integrated with a graphical user interface created in Visual Basic and an Oracle database. A simulation model of a manufacturing system with 4 shops, 18 machines, 10 families and 40 parts is created. Processing and setup times are generated using Erlang distributions and stored in the Oracle database. The integration of these tools allows for collaborative modeling and analysis to optimize manufacturing systems.
IJERD(www.ijerd.com)International Journal of Engineering Research and Develop...IJERD Editor
This document summarizes a research paper that proposes a new methodology for reducing additive distortion in steganography. The paper introduces a method to embed 2 bits of information in a pixel by altering only one bit plane. This is expected to make detection of covert communication more difficult for steganalysis algorithms compared to altering the least significant bit. The method uses Java for implementation and MATLAB to analyze histograms of original and stego images. Experimental results on embedding secret text in images are presented, along with analysis of the distortion levels and security of the proposed approach.
This document summarizes a research paper that classifies different types of networks and discusses their associated security issues. It categorizes networks based on size (LAN, MAN, WAN), design (peer-to-peer, client-server, standalone), layering (layered, non-layered), and provides examples such as Ethernet, Wi-Fi, VPNs. It also discusses common security threats for different network types like viruses, denial of service attacks, and evaluates security measures including encryption, firewalls, access control. The paper aims to provide a comprehensive classification of networks and analyze how security needs vary depending on the network and software development stages.
International Journal of Engineering Research and Development is an international premier peer reviewed open access engineering and technology journal promoting the discovery, innovation, advancement and dissemination of basic and transitional knowledge in engineering, technology and related disciplines.
This document analyzes and compares OFDMA and CDMA/WCDMA systems. It first discusses channel estimation techniques for OFDMA and CDMA, including minimum mean square error (MMSE) and least squares estimation. It then analyzes properties of OFDMA systems, including the effect of total power and cluster size on signal-to-interference plus noise ratio and signal-to-interference ratio. Finally, it compares the downlink capacities of OFDMA and WCDMA systems and proposes a new multiple access technique called OWCFDMA that combines advantages of both. The overall goal is to improve wireless communication system performance by integrating OFDMA and CDMA/WCDMA techniques.
1) The document discusses different control strategies for DSTATCOM (distribution static synchronous compensator), including Synchronous Reference Frame (SRF) methods, to mitigate voltage sags and compensate reactive power.
2) It analyzes the SRF method, SRF without phase locked loop (PLL), and a modified SRF method through mathematical modeling and MATLAB simulation.
3) The comparison of results from the different control strategies indicates that SRF provides effective compensation of voltage sags and reactive power under steady state conditions.
Design optimization of an axial flow compressor for industrial gas turbineeSAT Publishing House
This document summarizes the design optimization process of an axial flow compressor for an industrial gas turbine. It describes the steps taken, which included preliminary design using 1D and 2D simulations to select design parameters, computational fluid dynamics (CFD) analysis to validate the design, off-design performance mapping, blade profiling and 3D blade design, structural and modal analysis of the blades, and final 3D CFD flow analysis. The optimized design showed close agreement with the theoretical design goals of delivering the required mass flow at the target outlet pressure with wide stability margins at low losses.
CFX ANALYSIS OF AN IMPELLER BLADE DESIGN OF CENTRIFUGAL COMPRESSORIRJET Journal
This document summarizes a study analyzing the design of an impeller blade for a centrifugal compressor using CFX analysis software. The researchers aim to determine the optimal back-swept angle of the impeller blade to improve efficiency. They design blades with varying back-swept angles and simulate them in CFX to compare output parameters such as pressure ratio, temperature, Mach number, and efficiency. Their results show that back-swept angles between 15-30 degrees provide the best balance of increased pressure and low Mach number at the outlet. Accounting for both aerodynamic and manufacturing considerations, they conclude that 15-30 degrees is the optimal range for back-swept angle of the impeller blade design.
Optimization of time step and cfd study of combustion in di diesel engineeSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
This document summarizes a project report on analyzing air flow in a single cylinder four-stroke engine using computational fluid dynamics (CFD). The project involves 3D modeling of the engine cylinder in CREO and meshing in ANSYS GAMBIT. CFD simulations are performed using STAR-CD to analyze air flow for inlet manifold angles of 30 and 90 degrees. Post-processing of velocity vector diagrams, air particle motion diagrams, and kinetic energy plots from STAR-CD are used to determine the optimized inlet manifold design that provides better swirl motion within the engine cylinder.
Design, Analysis and Comparative Study of Exhaust Manifold for a Multi-Cylind...IRJET Journal
This document describes a study that used computational fluid dynamics (CFD) to analyze and optimize the design of an exhaust manifold for a multi-cylinder engine. Six different exhaust manifold models were designed using CAD software and analyzed using CFD to evaluate parameters like pressure, velocity, and temperature distributions. The goal was to identify a design that minimizes backpressure in the exhaust manifold to improve engine performance. Model 6, which used an elliptical cross-section shape, produced the most satisfactory results with low backpressure and high exhaust velocity.
EXPERIMENTAL STUDIES ON THE INTAKE PORT OF A DIESEL ENGINE TO DETERMINE SWIRLijmech
This paper focuses on experimentalstudies of intake port of a four cylinder diesel engine for different
vacuum pressures and valve lift positions. In this study, the cylinder head is experimented through a paddle
wheel flow setup, which gives the flow coefficient and swirl number asoutput. Main scope of the work is to
understand the flow behaviour through the intake port and finally to determine mean flow coefficient and
mean swirl number for different valve lift ratios L/D, where L is valve lift and D is bore diameter.
EXPERIMENTAL STUDIES, GEOMETRY ACQUISITION AND GRID GENERATION OF DIESEL ENGI...meijjournal
A typical diesel engine port is of complicated geometry . This paper addresses the experimental studies of intake port of a four cylinder diesel engine for different vacuum pressures and valve lift positions. In this study the cylinder head is experimented through a paddle wheel flow setup which gives the flow coefficient and swirl number as output. The main scope of the work is to understand the flow behaviour through the intake port and finally to determine mean flow coefficient and mean swirl number for different valve lift ratios L/D, where L is valve lift and D is bore diameter. This paper also addresses the geometry acquisition and grid generation for three dimensional Computational Fluid Analysis for flow filed computation and obtain a calibrated CFD code for future design once the code is validated with experimental results
Mechanical Engineering: An International Journal (MEIJ)meijjournal
A typical diesel engine port is of complicated geometry . This paper addresses the experimental studies of intake port of a four cylinder diesel engine for different vacuum pressures and valve lift positions. In this study the cylinder head is experimented through a paddle wheel flow setup which gives the flow coefficient and swirl number as output. The main scope of the work is to understand the flow behaviour through the
intake port and finally to determine mean flow coefficient and mean swirl number for different valve lift ratios L/D, where L is valve lift and D is bore diameter. This paper also addresses the geometry acquisition and grid generation for three dimensional Computational Fluid Analysis for flow filed computation and
obtain a calibrated CFD code for future design once the code is validated with experimental results
Experimental Studies, Geometry Acquisition and Grid Generation Of Diesel Engi...meijjournal
A typical diesel engine port is of complicated geometry . This paper addresses the experimental studies of
intake port of a four cylinder diesel engine for different vacuum pressures and valve lift positions. In this
study the cylinder head is experimented through a paddle wheel flow setup which gives the flow coefficient
and swirl number as output. The main scope of the work is to understand the flow behaviour through the
intake port and finally to determine mean flow coefficient and mean swirl number for different valve lift
ratios L/D, where L is valve lift and D is bore diameter. This paper also addresses the geometry acquisition
and grid generation for three dimensional Computational Fluid Analysis for flow filed computation and
obtain a calibrated CFD code for future design once the code is validated with experimental results
THREE DIMENSIONAL STUDIES ON FLOW DISTRIBUTIONS IN SAVONIOUS ROTORSIRJET Journal
This document describes a three-dimensional computational fluid dynamics (CFD) analysis of flow distributions in Savonious wind rotors. The study aims to provide a more realistic understanding of rotor behavior compared to previous two-dimensional analyses. A basic two-bucket Savonious rotor design is modeled using commercial CFD software. Velocity, pressure, and flow patterns are analyzed at different sections along the rotor and compared to 2D results. The 3D analysis provides more detailed insight into fluid flow near the rotor ends and within the buckets compared to 2D analyses.
The document discusses NREL's wind energy systems engineering initiative, which aims to develop an integrated software framework for modeling wind plant performance and costs from a systems perspective. The framework integrates various turbine and plant models from NREL's WISDEM suite using OpenMDAO. Initial analyses demonstrate the impact of system-level coupling on sensitivity and optimization studies compared to previous simplified models. The framework allows flexible configuration and improvement of models to better capture interactions across the full wind energy system over its lifetime.
IRJET - Review on Design of Intake Manifold for Air Restricted EngineIRJET Journal
This document reviews the design of intake manifolds for restricted engines used in formula racing events. It discusses several papers that analyzed different intake manifold designs through simulations and testing. The key goals of an intake manifold design are to maximize air flow through the restrictor, evenly distribute air to each cylinder, and improve engine performance metrics like volumetric efficiency and torque. The document examines factors like plenum volume, runner length and geometry, and restrictor shape. Simulation tools like Ricardo WAVE, VECTIS and CFD analysis in ANSYS were used to optimize these design parameters and evaluate manifold designs. The reviewed works aimed to enhance engine power output while meeting the restrictor requirement of racing competitions.
COMPUTATIONAL FLUID DYNAMIC ANALYSIS OF A PULSE JET ENGINEIRJET Journal
1) The document describes a computational fluid dynamics (CFD) analysis of different designs of a pulse jet engine, specifically investigating the impact of increasing the number of fuel inlets.
2) CFD simulations were conducted using ANSYS CFX software on CAD models created in Creo, including designs with single, three, and five fuel inlets.
3) The results show that designs with more fuel inlets generated higher thrust, pressure, and enthalpy compared to the single inlet design, with the five inlet design performing best.
IRJET- Analysis of Centrifugal Pump Impellers with Modified Micro GroovesIRJET Journal
This document analyzes centrifugal pump impellers with modified microgrooves through computational fluid dynamics (CFD) simulations. It describes the design of smooth, rectangular microgroove, and optimized semi-circular microgroove impellers using Solidworks. CFD analysis was performed using ANSYS CFX to compare the velocity, pressure, and turbulent kinetic energy distributions as well as the overall pump performance between the different impeller designs. The results show that the semi-circular microgroove impeller design improves pump efficiency over the baseline smooth and existing rectangular microgroove impeller designs.
Suction Duct Optimization for Fume Extraction SystemIRJET Journal
1. The document discusses optimization of the design of suction ducts for fume extraction systems. It compares the conventional design to a proposed new design using simulation software.
2. The simulation results show the conventional design has non-uniform extraction across inlets and reduced pressure and velocity at inlets further from the blower. The proposed design uses individual paths for each inlet with smooth junctions, improving flow uniformity.
3. Analysis of the mass flow rates across inlets found the proposed design increased uniformity compared to the conventional design, allowing more efficient extraction with the same blower capacity. The proposed design should be considered over the conventional to improve system efficiency.
Soot Formation in Diesel Engines By Using CfdIJERA Editor
In order to meet the stringent emission standards significant efforts have been imparted to the research and
development of cleaner IC engines. Diesel combustion and the formation of pollutants are directly influenced by
spatial and temporal distribution of the fuel injected. The development and validation of computational fluid
dynamics (CFD) models for diesel engine combustion and emissions is described. The complexity of diesel
combustion requires simulations with many complex interacting sub models in order to have a success in
improving the performance and to reduce the emissions. In the present work an attempt has been made to
develop a multidimensional axe-symmetric model for CI engine combustion and emissions. Later simulations
have been carried out. Commercial validation tool FLUENT was used for simulation. The tool solves basic
governing equations of fluid flow that is continuity, momentum, species transport and energy equation. Using
finite volume method turbulence was modeled by using RNG K-ɛ model. Injection was modeled using La
Grangian approach and reaction was modeled using non premixed combustion which considers the effects of
turbulence and detailed chemical mechanism into account to model the reaction rates. The specific heats were
approximated using piecewise polynomials. Subsequently the simulated results have been validated with the
existing experimental values
IRJET- Design and Analysis of Catalytic Converter of Automobile EngineIRJET Journal
This document summarizes a study on the design and analysis of a catalytic converter for an automobile engine. The researchers designed a baseline catalytic converter model using CAD software and analyzed it using computational fluid dynamics (CFD) to study the pressure and velocity distribution. They found high pressure losses and non-uniform flow distribution. Various modifications to the honeycomb structure diameter, thickness, and position as well as the inlet and outlet design were tested. The optimal design was found to have a centered inlet, conical inlets/outlets, and a honeycomb structure with 30mm holes positioned at the casing mid-length. This design showed improved uniform flow distribution and reduced pressure losses compared to the baseline design.
Modelling & Thermal analysis of pulse jet engine using CFDIRJET Journal
This document summarizes a study that used computational fluid dynamics (CFD) to analyze the combustion characteristics of a pulse jet engine. The study modeled a pulse jet engine design using CAD software and then conducted a CFD analysis using two different combustion models: an eddy dissipation model and a finite rate chemistry model. The results showed that the eddy dissipation model generated higher thrust than the finite rate chemistry model. Specifically, the eddy dissipation model produced higher exit pressures and velocities. The study concluded the proper selection of combustion model is important for accurately evaluating performance metrics like thrust generated from a pulse jet engine.
Cfd Studies of Two Stroke Petrol Engine ScavengingIJERA Editor
This project deals with the numerical analysis of 2 stroke engine scavenging in two cases. One with an existing condition (Flat headed pistons) and another with a new design (Dome headed piston) .The numerical analysis is done with help of CFD software ANSYS FLUENT 14.5. Here, the modeling of engine piston with flat headed type and with dome headed types was done in workbench. In ANSYS FLUENT after the geometrical design, for the dynamic motion meshing is used and set up species transport model also. At first the scavenging effect of flat headed piston is analyzed. Later the simulation of piston with dome headed type was also checked. Analyzing the variations from each and selected the best method for scavenging. Finally the scavenging efficiency is calculated for both type arrangements.
In cylinder cold flow cfd simulation of ic engine using hybrid approacheSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Similar to Welcome to International Journal of Engineering Research and Development (IJERD) (20)
A Novel Method for Prevention of Bandwidth Distributed Denial of Service AttacksIJERD Editor
Distributed Denial of Service (DDoS) Attacks became a massive threat to the Internet. Traditional
Architecture of internet is vulnerable to the attacks like DDoS. Attacker primarily acquire his army of Zombies,
then that army will be instructed by the Attacker that when to start an attack and on whom the attack should be
done. In this paper, different techniques which are used to perform DDoS Attacks, Tools that were used to
perform Attacks and Countermeasures in order to detect the attackers and eliminate the Bandwidth Distributed
Denial of Service attacks (B-DDoS) are reviewed. DDoS Attacks were done by using various Flooding
techniques which are used in DDoS attack.
The main purpose of this paper is to design an architecture which can reduce the Bandwidth
Distributed Denial of service Attack and make the victim site or server available for the normal users by
eliminating the zombie machines. Our Primary focus of this paper is to dispute how normal machines are
turning into zombies (Bots), how attack is been initiated, DDoS attack procedure and how an organization can
save their server from being a DDoS victim. In order to present this we implemented a simulated environment
with Cisco switches, Routers, Firewall, some virtual machines and some Attack tools to display a real DDoS
attack. By using Time scheduling, Resource Limiting, System log, Access Control List and some Modular
policy Framework we stopped the attack and identified the Attacker (Bot) machines
Hearing loss is one of the most common human impairments. It is estimated that by year 2015 more
than 700 million people will suffer mild deafness. Most can be helped by hearing aid devices depending on the
severity of their hearing loss. This paper describes the implementation and characterization details of a dual
channel transmitter front end (TFE) for digital hearing aid (DHA) applications that use novel micro
electromechanical- systems (MEMS) audio transducers and ultra-low power-scalable analog-to-digital
converters (ADCs), which enable a very-low form factor, energy-efficient implementation for next-generation
DHA. The contribution of the design is the implementation of the dual channel MEMS microphones and powerscalable
ADC system.
Influence of tensile behaviour of slab on the structural Behaviour of shear c...IJERD Editor
-A composite beam is composed of a steel beam and a slab connected by means of shear connectors
like studs installed on the top flange of the steel beam to form a structure behaving monolithically. This study
analyzes the effects of the tensile behavior of the slab on the structural behavior of the shear connection like slip
stiffness and maximum shear force in composite beams subjected to hogging moment. The results show that the
shear studs located in the crack-concentration zones due to large hogging moments sustain significantly smaller
shear force and slip stiffness than the other zones. Moreover, the reduction of the slip stiffness in the shear
connection appears also to be closely related to the change in the tensile strain of rebar according to the increase
of the load. Further experimental and analytical studies shall be conducted considering variables such as the
reinforcement ratio and the arrangement of shear connectors to achieve efficient design of the shear connection
in composite beams subjected to hogging moment.
Gold prospecting using Remote Sensing ‘A case study of Sudan’IJERD Editor
Gold has been extracted from northeast Africa for more than 5000 years, and this may be the first
place where the metal was extracted. The Arabian-Nubian Shield (ANS) is an exposure of Precambrian
crystalline rocks on the flanks of the Red Sea. The crystalline rocks are mostly Neoproterozoic in age. ANS
includes the nations of Israel, Jordan. Egypt, Saudi Arabia, Sudan, Eritrea, Ethiopia, Yemen, and Somalia.
Arabian Nubian Shield Consists of juvenile continental crest that formed between 900 550 Ma, when intra
oceanic arc welded together along ophiolite decorated arc. Primary Au mineralization probably developed in
association with the growth of intra oceanic arc and evolution of back arc. Multiple episodes of deformation
have obscured the primary metallogenic setting, but at least some of the deposits preserve evidence that they
originate as sea floor massive sulphide deposits.
The Red Sea Hills Region is a vast span of rugged, harsh and inhospitable sector of the Earth with
inimical moon-like terrain, nevertheless since ancient times it is famed to be an abode of gold and was a major
source of wealth for the Pharaohs of ancient Egypt. The Pharaohs old workings have been periodically
rediscovered through time. Recent endeavours by the Geological Research Authority of Sudan led to the
discovery of a score of occurrences with gold and massive sulphide mineralizations. In the nineties of the
previous century the Geological Research Authority of Sudan (GRAS) in cooperation with BRGM utilized
satellite data of Landsat TM using spectral ratio technique to map possible mineralized zones in the Red Sea
Hills of Sudan. The outcome of the study mapped a gossan type gold mineralization. Band ratio technique was
applied to Arbaat area and a signature of alteration zone was detected. The alteration zones are commonly
associated with mineralization. The alteration zones are commonly associated with mineralization. A filed check
confirmed the existence of stock work of gold bearing quartz in the alteration zone. Another type of gold
mineralization that was discovered using remote sensing is the gold associated with metachert in the Atmur
Desert.
Reducing Corrosion Rate by Welding DesignIJERD Editor
This document summarizes a study on reducing corrosion rates in steel through welding design. The researchers tested different welding groove designs (X, V, 1/2X, 1/2V) and preheating temperatures (400°C, 500°C, 600°C) on ferritic malleable iron samples. Testing found that X and V groove designs with 500°C and 600°C preheating had corrosion rates of 0.5-0.69% weight loss after 14 days, compared to 0.57-0.76% for 400°C preheating. Higher preheating reduced residual stresses which decreased corrosion. Residual stresses were 1.7 MPa for optimal X groove and 600°C
Router 1X3 – RTL Design and VerificationIJERD Editor
Routing is the process of moving a packet of data from source to destination and enables messages
to pass from one computer to another and eventually reach the target machine. A router is a networking device
that forwards data packets between computer networks. It is connected to two or more data lines from different
networks (as opposed to a network switch, which connects data lines from one single network). This paper,
mainly emphasizes upon the study of router device, it‟s top level architecture, and how various sub-modules of
router i.e. Register, FIFO, FSM and Synchronizer are synthesized, and simulated and finally connected to its top
module.
Active Power Exchange in Distributed Power-Flow Controller (DPFC) At Third Ha...IJERD Editor
This paper presents a component within the flexible ac-transmission system (FACTS) family, called
distributed power-flow controller (DPFC). The DPFC is derived from the unified power-flow controller (UPFC)
with an eliminated common dc link. The DPFC has the same control capabilities as the UPFC, which comprise
the adjustment of the line impedance, the transmission angle, and the bus voltage. The active power exchange
between the shunt and series converters, which is through the common dc link in the UPFC, is now through the
transmission lines at the third-harmonic frequency. DPFC multiple small-size single-phase converters which
reduces the cost of equipment, no voltage isolation between phases, increases redundancy and there by
reliability increases. The principle and analysis of the DPFC are presented in this paper and the corresponding
simulation results that are carried out on a scaled prototype are also shown.
Mitigation of Voltage Sag/Swell with Fuzzy Control Reduced Rating DVRIJERD Editor
Power quality has been an issue that is becoming increasingly pivotal in industrial electricity
consumers point of view in recent times. Modern industries employ Sensitive power electronic equipments,
control devices and non-linear loads as part of automated processes to increase energy efficiency and
productivity. Voltage disturbances are the most common power quality problem due to this the use of a large
numbers of sophisticated and sensitive electronic equipment in industrial systems is increased. This paper
discusses the design and simulation of dynamic voltage restorer for improvement of power quality and
reduce the harmonics distortion of sensitive loads. Power quality problem is occurring at non-standard
voltage, current and frequency. Electronic devices are very sensitive loads. In power system voltage sag,
swell, flicker and harmonics are some of the problem to the sensitive load. The compensation capability
of a DVR depends primarily on the maximum voltage injection ability and the amount of stored
energy available within the restorer. This device is connected in series with the distribution feeder at
medium voltage. A fuzzy logic control is used to produce the gate pulses for control circuit of DVR and the
circuit is simulated by using MATLAB/SIMULINK software.
Study on the Fused Deposition Modelling In Additive ManufacturingIJERD Editor
Additive manufacturing process, also popularly known as 3-D printing, is a process where a product
is created in a succession of layers. It is based on a novel materials incremental manufacturing philosophy.
Unlike conventional manufacturing processes where material is removed from a given work price to derive the
final shape of a product, 3-D printing develops the product from scratch thus obviating the necessity to cut away
materials. This prevents wastage of raw materials. Commonly used raw materials for the process are ABS
plastic, PLA and nylon. Recently the use of gold, bronze and wood has also been implemented. The complexity
factor of this process is 0% as in any object of any shape and size can be manufactured.
Spyware triggering system by particular string valueIJERD Editor
This computer programme can be used for good and bad purpose in hacking or in any general
purpose. We can say it is next step for hacking techniques such as keylogger and spyware. Once in this system if
user or hacker store particular string as a input after that software continually compare typing activity of user
with that stored string and if it is match then launch spyware programme.
A Blind Steganalysis on JPEG Gray Level Image Based on Statistical Features a...IJERD Editor
This paper presents a blind steganalysis technique to effectively attack the JPEG steganographic
schemes i.e. Jsteg, F5, Outguess and DWT Based. The proposed method exploits the correlations between
block-DCTcoefficients from intra-block and inter-block relation and the statistical moments of characteristic
functions of the test image is selected as features. The features are extracted from the BDCT JPEG 2-array.
Support Vector Machine with cross-validation is implemented for the classification.The proposed scheme gives
improved outcome in attacking.
Secure Image Transmission for Cloud Storage System Using Hybrid SchemeIJERD Editor
- Data over the cloud is transferred or transmitted between servers and users. Privacy of that
data is very important as it belongs to personal information. If data get hacked by the hacker, can be
used to defame a person’s social data. Sometimes delay are held during data transmission. i.e. Mobile
communication, bandwidth is low. Hence compression algorithms are proposed for fast and efficient
transmission, encryption is used for security purposes and blurring is used by providing additional
layers of security. These algorithms are hybridized for having a robust and efficient security and
transmission over cloud storage system.
Application of Buckley-Leverett Equation in Modeling the Radius of Invasion i...IJERD Editor
A thorough review of existing literature indicates that the Buckley-Leverett equation only analyzes
waterflood practices directly without any adjustments on real reservoir scenarios. By doing so, quite a number
of errors are introduced into these analyses. Also, for most waterflood scenarios, a radial investigation is more
appropriate than a simplified linear system. This study investigates the adoption of the Buckley-Leverett
equation to estimate the radius invasion of the displacing fluid during waterflooding. The model is also adopted
for a Microbial flood and a comparative analysis is conducted for both waterflooding and microbial flooding.
Results shown from the analysis doesn’t only records a success in determining the radial distance of the leading
edge of water during the flooding process, but also gives a clearer understanding of the applicability of
microbes to enhance oil production through in-situ production of bio-products like bio surfactans, biogenic
gases, bio acids etc.
Gesture Gaming on the World Wide Web Using an Ordinary Web CameraIJERD Editor
- Gesture gaming is a method by which users having a laptop/pc/x-box play games using natural or
bodily gestures. This paper presents a way of playing free flash games on the internet using an ordinary webcam
with the help of open source technologies. Emphasis in human activity recognition is given on the pose
estimation and the consistency in the pose of the player. These are estimated with the help of an ordinary web
camera having different resolutions from VGA to 20mps. Our work involved giving a 10 second documentary to
the user on how to play a particular game using gestures and what are the various kinds of gestures that can be
performed in front of the system. The initial inputs of the RGB values for the gesture component is obtained by
instructing the user to place his component in a red box in about 10 seconds after the short documentary before
the game is finished. Later the system opens the concerned game on the internet on popular flash game sites like
miniclip, games arcade, GameStop etc and loads the game clicking at various places and brings the state to a
place where the user is to perform only gestures to start playing the game. At any point of time the user can call
off the game by hitting the esc key and the program will release all of the controls and return to the desktop. It
was noted that the results obtained using an ordinary webcam matched that of the Kinect and the users could
relive the gaming experience of the free flash games on the net. Therefore effective in game advertising could
also be achieved thus resulting in a disruptive growth to the advertising firms.
Hardware Analysis of Resonant Frequency Converter Using Isolated Circuits And...IJERD Editor
-LLC resonant frequency converter is basically a combo of series as well as parallel resonant ckt. For
LCC resonant converter it is associated with a disadvantage that, though it has two resonant frequencies, the
lower resonant frequency is in ZCS region[5]. For this application, we are not able to design the converter
working at this resonant frequency. LLC resonant converter existed for a very long time but because of
unknown characteristic of this converter it was used as a series resonant converter with basically a passive
(resistive) load. . Here, it was designed to operate in switching frequency higher than resonant frequency of the
series resonant tank of Lr and Cr converter acts very similar to Series Resonant Converter. The benefit of LLC
resonant converter is narrow switching frequency range with light load[6] . Basically, the control ckt plays a
very imp. role and hence 555 Timer used here provides a perfect square wave as the control ckt provides no
slew rate which makes the square wave really strong and impenetrable. The dead band circuit provides the
exclusive dead band in micro seconds so as to avoid the simultaneous firing of two pairs of IGBT’s where one
pair switches off and the other on for a slightest period of time. Hence, the isolator ckt here is associated with
each and every ckt used because it acts as a driver and an isolation to each of the IGBT is provided with one
exclusive transformer supply[3]. The IGBT’s are fired using the appropriate signal using the previous boards
and hence at last a high frequency rectifier ckt with a filtering capacitor is used to get an exact dc
waveform .The basic goal of this particular analysis is to observe the wave forms and characteristics of
converters with differently positioned passive elements in the form of tank circuits.
Simulated Analysis of Resonant Frequency Converter Using Different Tank Circu...IJERD Editor
LLC resonant frequency converter is basically a combo of series as well as parallel resonant ckt. For
LCC resonant converter it is associated with a disadvantage that, though it has two resonant frequencies, the
lower resonant frequency is in ZCS region [5]. For this application, we are not able to design the converter
working at this resonant frequency. LLC resonant converter existed for a very long time but because of
unknown characteristic of this converter it was used as a series resonant converter with basically a passive
(resistive) load. . Here, it was designed to operate in switching frequency higher than resonant frequency of the
series resonant tank of Lr and Cr converter acts very similar to Series Resonant Converter. The benefit of LLC
resonant converter is narrow switching frequency range with light load[6] . Basically, the control ckt plays a
very imp. role and hence 555 Timer used here provides a perfect square wave as the control ckt provides no
slew rate which makes the square wave really strong and impenetrable. The dead band circuit provides the
exclusive dead band in micro seconds so as to avoid the simultaneous firing of two pairs of IGBT’s where one
pair switches off and the other on for a slightest period of time. Hence, the isolator ckt here is associated with
each and every ckt used because it acts as a driver and an isolation to each of the IGBT is provided with one
exclusive transformer supply[3]. The IGBT’s are fired using the appropriate signal using the previous boards
and hence at last a high frequency rectifier ckt with a filtering capacitor is used to get an exact dc
waveform .The basic goal of this particular analysis is to observe the wave forms and characteristics of
converters with differently positioned passive elements in the form of tank circuits. The supported simulation
is done through PSIM 6.0 software tool
Amateurs Radio operator, also known as HAM communicates with other HAMs through Radio
waves. Wireless communication in which Moon is used as natural satellite is called Moon-bounce or EME
(Earth -Moon-Earth) technique. Long distance communication (DXing) using Very High Frequency (VHF)
operated amateur HAM radio was difficult. Even with the modest setup having good transceiver, power
amplifier and high gain antenna with high directivity, VHF DXing is possible. Generally 2X11 YAGI antenna
along with rotor to set horizontal and vertical angle is used. Moon tracking software gives exact location,
visibility of Moon at both the stations and other vital data to acquire real time position of moon.
“MS-Extractor: An Innovative Approach to Extract Microsatellites on „Y‟ Chrom...IJERD Editor
Simple Sequence Repeats (SSR), also known as Microsatellites, have been extensively used as
molecular markers due to their abundance and high degree of polymorphism. The nucleotide sequences of
polymorphic forms of the same gene should be 99.9% identical. So, Microsatellites extraction from the Gene is
crucial. However, Microsatellites repeat count is compared, if they differ largely, he has some disorder. The Y
chromosome likely contains 50 to 60 genes that provide instructions for making proteins. Because only males
have the Y chromosome, the genes on this chromosome tend to be involved in male sex determination and
development. Several Microsatellite Extractors exist and they fail to extract microsatellites on large data sets of
giga bytes and tera bytes in size. The proposed tool “MS-Extractor: An Innovative Approach to extract
Microsatellites on „Y‟ Chromosome” can extract both Perfect as well as Imperfect Microsatellites from large
data sets of human genome „Y‟. The proposed system uses string matching with sliding window approach to
locate Microsatellites and extracts them.
Importance of Measurements in Smart GridIJERD Editor
- The need to get reliable supply, independence from fossil fuels, and capability to provide clean
energy at a fixed and lower cost, the existing power grid structure is transforming into Smart Grid. The
development of a smart energy distribution grid is a current goal of many nations. A Smart Grid should have
new capabilities such as self-healing, high reliability, energy management, and real-time pricing. This new era
of smart future grid will lead to major changes in existing technologies at generation, transmission and
distribution levels. The incorporation of renewable energy resources and distribution generators in the existing
grid will increase the complexity, optimization problems and instability of the system. This will lead to a
paradigm shift in the instrumentation and control requirements for Smart Grids for high quality, stable and
reliable electricity supply of power. The monitoring of the grid system state and stability relies on the
availability of reliable measurement of data. In this paper the measurement areas that highlight new
measurement challenges, development of the Smart Meters and the critical parameters of electric energy to be
monitored for improving the reliability of power systems has been discussed.
Study of Macro level Properties of SCC using GGBS and Lime stone powderIJERD Editor
The document summarizes a study on the use of ground granulated blast furnace slag (GGBS) and limestone powder to replace cement in self-compacting concrete (SCC). Tests were conducted on SCC mixes with 0-50% replacement of cement with GGBS and 0-20% replacement with limestone powder. The results showed that replacing 30% of cement with GGBS and 15% with limestone powder produced SCC with the highest compressive strength of 46MPa, meeting fresh property requirements. The study concluded that this ternary blend of cement, GGBS and limestone powder can improve SCC properties while reducing costs.
Study of Macro level Properties of SCC using GGBS and Lime stone powder
Welcome to International Journal of Engineering Research and Development (IJERD)
1. International Journal of Engineering Research and Development
e-ISSN: 2278-067X, p-ISSN : 2278-800X, www.ijerd.com
Volume 5, Issue 9 (January 2013), PP. 41-45
Radial Inflow Gas Turbine Flow Path Design
Samip Shah1, Gaurang Chaudhri2, Digvijay Kulshreshtha3, S. A. Channiwalla4
1,2,3
C.K.Pithawalla College of Engineering and Technology, Assistant Professor, Surat.
4
S.V.National Institute of Technology, Professor, Surat.
Abstract:- A new method for radial inflow gas turbine flow paths design based on a unique integrated
conceptual design environment AxSTREAM is presented in this paper. This integrated environment is
a seamless and swift processing scheme that incorporates stages aerodynamic analysis and preliminary
design/sizing based on the one dimensional method. The environment makes possible to find number
of different designs with inverse task solver, basing on initially specified boundary conditions, closing
conditions and design variables. Design space explorer provides easy and visual comparison for range
of obtained design in customizable coordinate axes. Solution filtering on different parameters, such as
meridional and axial dimensions, maximal blades weight, saving the time to choose from thousands
obtained solutions the only one right design. Flexibility of presented approach allows to built-up
complete gas turbine flow path from consequence of individual elements: stationary and rotating
elements, ducts, heat exchangers, and analyze it in common environment. Complete control of all
aspects of aerodynamic flow path quality, structural reliability, and integral performances on design
and offdesign conditions is performing throughout all design process. This gives full interaction
between user and system for immediate correction and enhancement of current design data using
various optimization capabilities to feel the impact of changes on each design step. Integrated system
AxSTREAM significantly shortening the design cycle time from initial machine concept to finalized
design with all offdesign performances details. The design process is demonstrated for a 25kW radial
inflow gas turbine.
Keywords:- Radial Inflow Turbine, Performance Maps, AxSTREAM
I. INTRODUCTION
World’s increasing demands in energy, as well as transportation market growth emerges gas turbine
manufacturers to be proactive. They have to design machines, that satisfies today’s requirements of highest
efficiency (i.e. minimal fuel consumption), ability to operate in some certain range of conditions, weight
restrictions. To be as much competitive as possible, design cycle shortening and intensifying is necessarily too.
That’s why question creation of new generation of gas turbine preliminary design environment raised up high
last years. As it well-known, most of machine’s geometrical properties selects on phase of preliminary design
and remain almost unchangeable throughout next design phases, predefining its layout significantly. Therefore,
preliminary design task is basis that should be selected very carefully. But from other side, it can be a number of
different options that also can be found useful and need to be considered. This paper is describing theoretical
backgrounds and internal structure of integrated gas turbine preliminary design system [1,2]. At the end process
is demonstrated for 25kW radial inflow gas turbine with off design performance.
In recent years, methods for turbomachinery flow path design have greatly improved due to
introduction of three dimensional (3D) viscous flow concepts. But one dimensional (1D) and two dimensional
(2D) calculations are also beneficial, especially at the early stage of design. This paper describes the step in
turbomachinery conceptual design, which uses 1D calculation [3].
Design of new turbomachinery is a long and complex process. It can be considered as a sequence of several
steps.
They are:
Preliminary design (sizing)
Meanline and streamline flow path analysis
Profiling and blade design
Structure and model analysis
Flow analysis
The design of radial turbines, begins with a design specification, and proceeds through preliminary
design to blade design and finally analysis using increasingly sophisticated tools. A competitive product
demands a high level of design optimization, and if this is to be done cost-effectively, an integrated design
41
2. Radial Inflow Gas Turbine Flow Path Design
system is required to enable the designer to bring various design tools to bear at appropriate design points in the
process. The design system must also allow the efficient transfer of information, because design is rarely a
simple linear process, but almost always involves considerable iteration and development of design concepts in
parallel [3,4]. A number of methods have been suggested for obtaining the overall dimensions of radial gas
turbines; the most notable has been that presented by Rohlik[5] in the form of charts related to specific speed
and defined slip as the ratio of the tangential velocity at the rotor inlet to the rotor tip speed. Benson[6,7] has
analyzed the performance of radial turbines, the methods used in these analysis will be used for the development
of the procedure for the prediction of the overall dimensions. Stanitz's [8] formula for the relationship between
the slip factor and the number of blades for compressors will be used. The aggregate losses due to friction in the
blade passages, clearance effects and disk friction are difficult to predict except on past experience. Benson [9]
has made an extensive analysis of a number of radial turbines and has reported on a method for evaluating these
losses from test data. The method of analysis developed by Benson to predict the performance characteristics of
radial gas turbines is the basis of the design procedure. Baines [10,11] suggested an integrated approach to
design a radial inflow turbine.
II. REQUIREMENTS FOR GAS TURBINE INTEGRATED DESIGN ENVIRONMENT
Before design system creation is started, its developers have to outline obligatory requirements, which
make such software concept satisfying end-users needs and meets modern turbomachinery design standards.
Overview of different theoretical sources and a real design system, implemented in companies, are available in
software to establish new design system requirements. Mainly, preliminary design system is integrated with
aerodynamic performances analysis to perform study of designed machine and capabilities to alternate between
created designs to make refinement, basing on design generated. Additional, but useful features of this system
are design of repeating stages, capability to maintain specific design diameter, specification of stages reaction
ranges for design, capability to stay in limited axial sizes ranges and weight ranges. One of the main
requirements of such system is fast turnaround time with ability to create and consider extensive number of
various designs, be able to find trade-off between existing constraints and required outputs. Machine’s various
layout configurations and additional elements, such as ducts, exhaust diffusers, surge valves and others, can be
used in gas turbine and effect its performances, thus taken into account as part of system design process.
Radial Inflow Gas Turbine Design In Integrated Envinronment
Traditionally, for radial inflow turbine operation analysis for design and off-design points, the
verification analysis problem has been performed in 1D formulations. In verification analysis of a radial inflow
turbine, flow is treated as one-dimensional only [10]. Obviously, there is significant 3D flow in a radial inflow
turbine. In contrast to 3D viscous flow calculations in a flow path, simplified 1D methods provide a close
approximation for experimental data depending on the quality of empirical methods used to determine losses.
Integrated environment AxSTREAM was used to design radial inflow gas turbine by applying
aerodynamic concept. An analysis based on AxSTREAM software requires numbers of internal iteration, but the
designer will almost certainly have to repeat it a number of times with different starting parameters in order to
achieve acceptable turbine geometry. The inlet total pressure can be specified initially. The exit pressure is set
by ambient pressure to which turbine exhaust, so that the efficiency is eventually determined by the pressure
ratio. Input data and parameters required for the analysis are given in Table 4.1.
Table I: Design point technical requirement and parameters
Empirical Models Applied for Design
The next empirical losses and deviation models were used for radial inflow turbine design and
calculation procedure [4]:
• Radial turbine profile losses – by Craig & Cox
42
3. Radial Inflow Gas Turbine Flow Path Design
• Radial turbine deviation – by Stepanov
For this data, more than 150 design points were found by the software. Efficiency – flow rate
coefficients and typical load diagrams are shown in Fig 1. Point color corresponds to efficiency level. The data
point having maximum efficiency was selected for the design and analysis of turbine. Dimensions of turbine in
maridional plane are shown in figure 3. Whereas figure 2 shows enthalpy- entropy diagram for 25 kW of radial
inflow gas turbine.
IV. RESULTS AND DISCUSSION
The design procedure provides an estimate of rotor dimension, from which the different ratios for
turbine design can be calculated. The radius ratio of turbine hub to shroud at exit is 0.3099 by AxSTREAM.
Baines [11] and Glassman [15] suggested this radius ratio is limited by crowding of the blades and it should be
set as 0.3. The radius ratio of turbine shroud to tip is 0.6914. Rohlik[5] recommended that this ratio should not
be exceed 0.7. The rotor tip width/tip diameter form AxSTREAM is 0.082. G. F. Hiett and I. H. Johnston [16]
suggested that rotor tip width/tip diameter of 0.1 appears to be about optimum for maximum efficiency. This
suggested that the turbine dimensional ratios calculated by AxSTREAM are very much nearer to the design
ratios found in literature.
Fig 1: Estimated diagrams for radial inflow turbine Fig. 2: Enthalpy- Entropy diagram
efficiency
Fig. 3 : Dimension of turbine in maridional plane Fig. 4: Velocity triangle at inlet and exit
The blade speed is around 505m/s by meanline calculation, which is fairly high but should be
acceptable for common rotor materials such as Kersit601, SS 304 or 316 at operating temperature. This will
depend on the duty cycle and life requirements of radial turbine and a final decision must be made when
structure analysis is carried out, but the value found here gives confidence that it is safe to proceed.
The rotor flow angle is -28˚, which give good incidence on to a radial inlet blade. This angle should be less than
-40˚ suggested by Woolley and Hatton [12] and Yeo and Baines [17].
43
4. Radial Inflow Gas Turbine Flow Path Design
The flow coefficient of radial turbine by AxSTREAM is 0.396. This value should be in the range of 0.2 to 0.3
suggested by A. Whitfield and N.C. Baines [11]. So, further reduction in the loading coefficient is required.
Since the power output and mass flow rate are fixed, this implies an increase in blade speed.
Other checks on the validity of the original assumptions can also be made before proceeding. The static pressure
is 1.055 bar which is likely to be about the right level for exhausting to ambient pressure with some exhaust
system loss. If the exit static pressure is appreciably higher or lower than ambient, corresponding adjustments to
the inlet total pressure should be made and the procedure repeated.
III. OFF-DESIGN PERFORMANCES STUDY FOR SYNTHESIZED MACHINE
Off-design Study Theoretical Background
Off-design conditions study and comparison of generated designs is additional point of interest. Off-
design calculation requires only variation of boundary conditions: pressure, rotation speed and others for the
fixed geometry in direct task. This makes no principal difference between direct task calculation on design and
off-design modes in presented approach. As it was discussed above, specific empirical losses models can be
applied in direct task for each machine. After applying proper loss models it’s possible to take into account
variation of number of important effects, such as profile and secondary losses change depending on off-design
conditions, deviation angle variation and calculate critical off-design incidence angles for radial inflow turbine
for selected profile geometry. Maps are especially critical in case of turbine designs comparison, where they can
have significant influence on design application. Other important question is correct operation ranges prediction.
This problem also can be solved by application of real losses models and loss limits to calculation in direct task.
Equation set solving results in some discrepancy accuracy on each step, and depending on selected accuracy
limits and number of iteration steps performed, different accuracy could be obtained, that indicates stability of
current calculated mode. Of course, question of proper loss models selection, as well as applying correct limits
and scale coefficient, is crucial for correct operating range determination for each machine type, but it can be
resolved to determine right models through model evaluation and comparison with experiment.
In recent years great attention has been paid to radial inflow turbines, especially in those applications
where small turbomaehines are required. An investigation has therefore been carried out in order to obtain a
method suitable to predict the off-design performances of such a turbomachine. An off-design performance of a
radial-inflow turbine is presented by using software AxSTREAM. The software uses one/two-dimensional
solution of flow conditions through the turbine passage. The loss model accounts for stator, rotor, incidence,
and exit losses. Overall turbine geometry and design-point values of efficiency, pressure ratio, and mass flow
are needed as input information. The output includes performance parameters for any number of given speeds
over a range of turbine pressure ratio.
Rotational speed of the turbine has been varied between 1,00,000 to 2,00,000 rpm and static pressure
varied between 1.0 to 1.2 bar. The results obtained are plotted in Figures 5 to 7 for 7 1D 7 calculation, which
shows turbine maps, expressing pressure ratio, total to total efficiency and total to static efficiency as a function
of turbine speed.
Fig. 5: Mass flow rate vs pressure ratio for variable speed (2D calculation)
Fig. 6: Mass flow rate vs total to total efficiency for variable speed (2D calculation)
44
5. Radial Inflow Gas Turbine Flow Path Design
Fig. 7: Mass flow rate vs total to static efficiency for variable speed (2D calculation)
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