The Research About Automotive Engine Ignition Microwiave Technology

Microwave ignition technology very promising, use it for automobile engine ignition to replace the spark plug ignition as a new ignition, that can reduce the consumption of energy and reduce toxic gas emissions. All along, the spark ignition engine has been accounted for automotive ignition lead the way, from single to multi-point ignition, has been improved, while it has been used a spark plug technology. With the development of microwave ignition technology, people found that the ignition in the car engine, that can make the fuel more fully, and can reduce toxic gas emissions. Currently research is thorough, has a microwave in a single cylinder ignition for experiments, but some literature reported, QWCCR microwave ignition can be applied in lean burn.In this paper, we research it from the microwave energy applicaions, refer to the microwave igniter literature, serious study of the theoretical part, and then the preliminary design out a quarter wavelength Microwave igniter coaxial cavity size, using HFSS software simulation advantage, to the simulation of initial size, getting the results of analysis and optimization,to the simulation of initial size, getting the results of analysis and optimization,the first design of a microwave coaxial cavity igniter, then machining, to do the test and experiment. This content can be classified into the two parts:The first part analyzes the electromagnetic characteristics of the resonator, including Q cavity, the cavity in various loss as well as the inner conductor cutting-edge electric field, one of the most important is the tip of the inner conductor of the electric field, it can field strength of the relationship between the breakdown of gas around it, so need to design the initial structure size of the cavity design the initiating structural dimensions of the cavity. Then use the HFSS software to simulate and calculation, and get the preliminary results to analyze. Average working pressure in the engine combustion chamber is 6-8 atm.And at 10 atm, the threshold generating plasma flame is 72.25 ?10 V/ m,when the input power of microwave is 1W. The electric field obtained by simulation reach the tip of the inner conductor is 61?10 V/ m, so that the combustion chamber of combustible gas is ignited,that need the input microwave power of hundreds of watts. Then the size of the cavity structure to optimize the size of the package over the structure and the inner and outer conductors coupling structure, the morphology of the inner conductor tip modification and cavity height, therefore the tip of the electric field inside the conductor reached the design target.The second part, when we get the final igniter cavity structure, drawing, using the right material, designing the right structural to adjust the frequency of the cavity, finally processing the cavity. Then, after the part of the coupling ring, the inner conductors installed, use a vector network analyzer to test the cavity ignition. Adjust the height of the cavity to change the resonance frequency. From the simulation curve and the test curve comparison, analysis the result of the cavity ignition. Finally, design our ignition experiment, find the bale equipment used in the experiments, and record experimentally and attention to the microwave radiation protection and so on, Finally add the microwave source to the cavity to test the ignition in air, the results of ignition experiment will be compared with the cavity design.