Numerical investigation of the structure of a silicon six-wafer micro-combustor under the effect of hydrogen/air ratio
- Authors: Zhu, Lin , Jen, Tien-Chien , Ji, Ying-Feng , Yin, Cheng-Long , Zhu, Mei
- Date: 2010
- Subjects: Micro-combustors
- Type: Article
- Identifier: uj:5266 , http://hdl.handle.net/10210/14935
- Description: Research reports indicate that sufficiently high equivalence ratio of the hydrogen/air mixture leads to the upstream burning in the recirculation jacket, possibly damaging the micro- combustor due to the high wall temperature. This work investigates the influences of the equivalence ratio of the mixture on the structure of a micro-combustor device. Numerical simulation approaches focused on the structural design of the micro-combustor with the flame burning in the recirculation jacket. Combustion characteristics of the combustor were first analysed based on 2D computational Fluid Dynamics (CFD), and then thermo-mechanical analysis on the combustor was carried out by means of 3D Finite Element Analysis (FEA) method. The results showed that the most dangerous locations where the critical failure could possibly occur lay at the burning areas in the recirculation jacket due to the poor bonding, the high temperature and the residual stress. The results of this study can be used for the design and improvement of the micro-combustors.
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Structural design of a silicon six-wafer micro-combustor under the effect of heat transfer boundary condition at the outer walls
- Authors: Zhu, Lin , Jen, Tien-Chien , Zhu, Mei , Yin, Cheng-Long , Kong, Xiao-Ling
- Date: 2010
- Subjects: Micro-combustors , Heat transfer
- Type: Article
- Identifier: uj:5281 , http://hdl.handle.net/10210/14950
- Description: The aim of this investigation was to establish a methodology for designing highly stressed micro fabricated structures by studying the structural design issues associated with a silicon six–wafer micro combustor under the effect of heat transfer boundary condition at the outer walls. Some experimental and numerical simulation results have indicated that the flame can not be sustained in the micro combustor if the poor heat transfer coefficients at the outer wall are present. This could cause the combustor wall temperature higher than the auto ignition temperature of reactants and results in the upstream burning. Since silicon has relatively poor high temperature strength and creep resistance when the temperature is above the brittle to ductile transition temperature (BDTT), e.g. 900K, the combustion in the recirculation jacket could possibly damage the micro combustor due to the high wall temperature.
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