论文部分内容阅读
微波点火是一种具有发展前景的点火方式,然而目前的微波点火方法大多采用1/4同轴谐振腔作为点火装置,点火效果较差。为改进这种微波点火方法,对圆柱形微波谐振腔展开研究,提出了基于圆柱形谐振腔的微波点火方法。圆柱形谐振腔主要有TE_(111)和TM_(010)这2种谐振模式。通过理论分析和仿真模拟,分别设计了基于2种谐振模式的试验装置。得到结果如下:利用基于TE_(111)谐振模式的试验装置成功实现了点火,但是工作气压较低,只有0.012 MPa;而利用基于TM_(010)谐振模式的试验装置可实现1MPa下的稳定点火,这种点火方式可以提高点火可靠性、拓宽稀薄燃烧的极限。此外,还通过在TM_(010)谐振腔内部增加多个金属尖端的方式实现了多点点火。与火花塞点火相比,微波点火方法可以加快燃烧速度、提高热效率,使其到达压力峰值的时间缩短15%,同时可以提高5%的峰值压力。
Microwave ignition is a promising ignition method, however, most of the current microwave ignition methods use a 1/4 coaxial resonator as an ignition device, and the ignition effect is poor. In order to improve this kind of microwave ignition method, the cylindrical microwave resonator is studied, and a microwave resonator based on cylindrical resonator is proposed. There are two resonant modes of the cylindrical resonator: TE_ (111) and TM_ (010). Through the theoretical analysis and simulation, the experimental devices based on two resonant modes are designed respectively. The results were as follows: The ignition was successfully achieved by the test device based on the TE 111 resonance mode, but the working pressure was low, only 0.012 MPa. With the TM 010 resonance mode, This ignition method can improve the ignition reliability, broaden the lean burn limit. In addition, multi-point ignition is also achieved by adding multiple metal tips inside the TM_ (010) resonator. Compared with the ignition spark plug, microwave ignition method can speed up the combustion rate, improve thermal efficiency, to reach the peak pressure time reduced by 15%, while 5% can increase the peak pressure.