The Experts below are selected from a list of 35550 Experts worldwide ranked by ideXlab platform
M A Meyers - One of the best experts on this subject based on the ideXlab platform.
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consolidation of combustion synthesized titanium diboride based materials
Journal of the American Ceramic Society, 1995Co-Authors: Darren A Hoke, M A MeyersAbstract:The quasi-static consolidation in uniaxial compression of combustion-synthesized TiB{sub 2}-based materials was investigated. Consolidation was carried out in insulated containers upon completion of the combustion reaction, while the porous reaction products were ductile. Since the consolidation is not an Isothermal Process, the temperature change during consolidation was monitored and recorded. The effect of the addition of metallic elements to the elemental powders was established, and it was found that nickel and chromium provide the best compact integrity. The partial densification is sufficient to show significant differences between the effects of metallic additives. A phenomenological (not based on the micromechanisms of densification) constitutive model was applied to the hot and porous reaction products incorporating the temperature dependence of flow stress. The activation energy for the temperature dependence of the flow stress is established and indicates that, in addition to diffusion-induced plastic deformation, other Processes occur, such as fracturing of ligaments.
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Consolidation of Combustion‐Synthesized Titanium Diboride‐Based Materials
Journal of the American Ceramic Society, 1995Co-Authors: Darren A Hoke, M A MeyersAbstract:The quasi-static consolidation in uniaxial compression of combustion-synthesized TiB{sub 2}-based materials was investigated. Consolidation was carried out in insulated containers upon completion of the combustion reaction, while the porous reaction products were ductile. Since the consolidation is not an Isothermal Process, the temperature change during consolidation was monitored and recorded. The effect of the addition of metallic elements to the elemental powders was established, and it was found that nickel and chromium provide the best compact integrity. The partial densification is sufficient to show significant differences between the effects of metallic additives. A phenomenological (not based on the micromechanisms of densification) constitutive model was applied to the hot and porous reaction products incorporating the temperature dependence of flow stress. The activation energy for the temperature dependence of the flow stress is established and indicates that, in addition to diffusion-induced plastic deformation, other Processes occur, such as fracturing of ligaments.
Darren A Hoke - One of the best experts on this subject based on the ideXlab platform.
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consolidation of combustion synthesized titanium diboride based materials
Journal of the American Ceramic Society, 1995Co-Authors: Darren A Hoke, M A MeyersAbstract:The quasi-static consolidation in uniaxial compression of combustion-synthesized TiB{sub 2}-based materials was investigated. Consolidation was carried out in insulated containers upon completion of the combustion reaction, while the porous reaction products were ductile. Since the consolidation is not an Isothermal Process, the temperature change during consolidation was monitored and recorded. The effect of the addition of metallic elements to the elemental powders was established, and it was found that nickel and chromium provide the best compact integrity. The partial densification is sufficient to show significant differences between the effects of metallic additives. A phenomenological (not based on the micromechanisms of densification) constitutive model was applied to the hot and porous reaction products incorporating the temperature dependence of flow stress. The activation energy for the temperature dependence of the flow stress is established and indicates that, in addition to diffusion-induced plastic deformation, other Processes occur, such as fracturing of ligaments.
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Consolidation of Combustion‐Synthesized Titanium Diboride‐Based Materials
Journal of the American Ceramic Society, 1995Co-Authors: Darren A Hoke, M A MeyersAbstract:The quasi-static consolidation in uniaxial compression of combustion-synthesized TiB{sub 2}-based materials was investigated. Consolidation was carried out in insulated containers upon completion of the combustion reaction, while the porous reaction products were ductile. Since the consolidation is not an Isothermal Process, the temperature change during consolidation was monitored and recorded. The effect of the addition of metallic elements to the elemental powders was established, and it was found that nickel and chromium provide the best compact integrity. The partial densification is sufficient to show significant differences between the effects of metallic additives. A phenomenological (not based on the micromechanisms of densification) constitutive model was applied to the hot and porous reaction products incorporating the temperature dependence of flow stress. The activation energy for the temperature dependence of the flow stress is established and indicates that, in addition to diffusion-induced plastic deformation, other Processes occur, such as fracturing of ligaments.
M A Arrancojimenez - One of the best experts on this subject based on the ideXlab platform.
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multi objective thermodynamic based optimization of output power of solar dish stirling engine by implementing an evolutionary algorithm
Energy Conversion and Management, 2013Co-Authors: Mohammad Hossei Ahmadi, Ami H Mohammadi, Saeed Dehghani, M A ArrancojimenezAbstract:Abstract A solar-powered high temperature differential Stirling engine has been considered for optimization with multiple criteria. A mathematical model based on the finite-time thermodynamics has been developed so that the output power and thermal efficiency and the rate of entropy generation of the solar Stirling system with finite rate of heat transfer, regenerative heat loss, conductive thermal bridging loss and finite regeneration Process time are obtained. Furthermore, imperfect performance of the dish collector and convective/radiative heat transfer mechanisms at the hot end as well as the convective heat transfer at the heat sink of the engine are considered in the developed model. Three objective functions including the output power and overall thermal efficiency have been considered simultaneously for maximization and the rate of entropy generation of the Stirling engine are minimized at the same time. Multi-objective evolutionary algorithms (MOEAs) based on NSGA-II algorithm has been employed while the Effectiveness’s of regenerator, the Effectiveness’s of the low temperature heat exchanger, the Effectiveness’s of the high temperature heat exchanger, heat capacitance rate of the heat sink, heat capacitance rate of the heat source, temperatures of the working fluid in the high temperature Isothermal Process and temperatures of the working fluid in the low temperature Isothermal Process are considered as decision variables. Pareto optimal frontier has been obtained and a final optimal solution has been selected using various decision-making approaches including the fuzzy Bellman–Zadeh, LINMAP and TOPSIS methods.
Huawei Chang - One of the best experts on this subject based on the ideXlab platform.
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thermodynamic design of stirling engine using multi objective particle swarm optimization algorithm
Energy Conversion and Management, 2014Co-Authors: Che Dua, Xinggang Wang, Shuiming Shu, Changwei Jing, Huawei ChangAbstract:Abstract In the recent years, the interest in Stirling engine has remarkably increased due to its ability to use any heat source from outside including solar energy, fossil fuels and biomass. A large number of studies have been done on Stirling cycle analysis. In the present study, a mathematical model based on thermodynamic analysis of Stirling engine considering regenerative losses and internal irreversibilities has been developed. Power output, thermal efficiency and the cycle irreversibility parameter of Stirling engine are optimized simultaneously using Particle Swarm Optimization (PSO) algorithm, which is more effective than traditional genetic algorithms. In this optimization problem, some important parameters of Stirling engine are considered as decision variables, such as temperatures of the working fluid both in the high temperature Isothermal Process and in the low temperature Isothermal Process, dead volume ratios of each heat exchanger, volumes of each working spaces, effectiveness of the regenerator, and the system charge pressure. The Pareto optimal frontier is obtained and the final design solution has been selected by Linear Programming Technique for Multidimensional Analysis of Preference (LINMAP). Results show that the proposed multi-objective optimization approach can significantly outperform traditional single objective approaches.
Tianju Liao - One of the best experts on this subject based on the ideXlab platform.
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optimum performance characteristics of a solar driven stirling heat engine system
Energy Conversion and Management, 2015Co-Authors: Tianju LiaoAbstract:Abstract A solar-driven Stirling heat engine system composed of a Stirling heat engine, a solar collector, and a heat sink is presented, in which the radiation and convection heat losses of the solar collector, the heat-leak between the thermal absorber and heat sink, the regenerative losses of the Stirling heat engine, and the energy balance between the thermal absorber and the high Isothermal Process of the Stirling heat engine are taken into consideration. Based on the irreversible thermodynamics and Lagrange multiplier method, the maximum power output and the corresponding optimal efficiency of the system are determined and the absorber temperature that maximizes the optimal system efficiency is calculated numerically. The influences of some system parameters such as the concentrating ratio, the volume ratio during the regenerative Processes and irreversibilities of heat exchange Processes on the optimal efficiency are analyzed in details. The results obtained here may provide a new idea to design practical solar-driven Stirling heat engine system.