Combustion Characteristic And Structure Failure Of A Silicon Micro Combustor

The combustion-based micro-power device, such as a micro-gas turbine engine, is considered as a novel battery, because it can produce power in a volume less than from several cubic centimeters to dozens of cubic centimeters. It is its excellent advantages over other batteries that make itself attracted by all the countries around the world. Having analyzed the above, the objective of the thesis is to perform numerical simulations to analyse the performance of the micro-combustor under various conditions based on the prototype used in the MIT micro-gas turbine, such as its combustion behaviour, stress and strain condition as well as evaluating its fatigue life. The thesis is specifically intended to1) analyze the combustion behaviour of a six-wafer micro-combustor. In detail, firstly we performed a two-dimensional numerical simulation to investigate the effect of various conditions, say, the hydrogen/air ratio, the hydrogen/air mass flow rate and the heat loss through the outer wall of the micro combustor, and then we compared the computing results above with the experimental studies on the micro combustor from MIT in order to verify whether or not the approaches used in the thesis are right.2) assemble the micro-combustor based on virtual assembly techniques. Based on the prototype used in the MIT micro-gas turbine engine, an idea of creating its three-dimensional micro-combustor with virtual assembly technique was proposed after analyzing the traditional approaches of geometric modeling in the field of CFD. In detail, the theory and the process of virtual assembly techniques were firstly depicted, and then the three-dimensional micro-combustor was constructed to demonstrate the idea in SolidWorks with virtual design techniques, such as modeling techniques based on features, virtual assembly techniques and the exploded view. Lastly, the structure of a micro-combustor created in the thesis is compared with the one made in Singapore to verify whether or not the approaches used in the thesis are right.3) study the failure occurring on the micro-combustor. Based on the combustion behaviour of a micro-combustor, either theoretic or computational approaches were performed to study the failure on the micro-combustor without regard to the residual stress from the fabrication process. In detail, FEA was firstly performed to.investigate the structure of a micro-combustor either in non- burning in the recirculation jacket or burning in the recirculation jacket. And then fuzzy probability was employed to evaluate the fatigue life of the micro-combustor. Lastly, the computing results above is compared with the experimental studies on the micro combustor from MIT in order to verify whether or not the approaches used in the thesis are right.In general, a two-dimensional numerical simulation was performed to investigate the effect of various conditions in view of 19 reversible elementary reactions and nine species; an idea of creating the three-dimensional micro-combustor with virtual assembly techniques was proposed after analyzing the traditional approaches of geometric modeling in the field of CFD; either theoretic or computational approaches were performed to study the failure on the micro-combustor without regard to the residual stress from the fabrication process. The objective we try to do in the thesis is to seek a new approach to design a micro-combustor in order to build up a solid foundation to optimize the micro-combustor.