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Development of Plasma Torches with High Performance for Scramjet Combustors.

超燃冲压发动机燃烧室高性能等离子炬的开发。

基本信息

批准号：
07555608
负责人：
KIMURA Itsuro
金额：
$ 1.47万
依托单位：
Tokai University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

项目摘要

For the ignition and flame stabilization in combustors of scramjet engines, a method where an arc discharge is formed along the wall (direct arc discharge method) was proposed. In the direct arc discharge method, chemically active radicals produced by arc discharges can be used more effectively compared to the case of conventional plasma torches. Following results were obtained :1. The direct arc discharge method showed an excellent ability for the ignition and flame stabilization in supersonic flows, when the cathode is placed at upstream and the anode, at downstream flatly to the wall surface, and a carrier gas is injected through the gap of them.2. For the case with a wall step, a geometry, where the upstream surface is taken as cathode, and the downstream surface, as anode, and a carrier gas is injected through the gap at the bottom of the step, showed a successful result.3. Fuel-air mixtures showed an excellecn ability as carier gases.An experimental study was made to establish low power plasma jets (order of 100 W) with high exhaust gas temperature and high thermal efficiency. From detailed examination on the distance between cathode and anode, and the anode geometry, following results were obtained :1. Low power nitrogen plasma jets with a stable operation under atmospheric pressure were established with the combination of a high voltage power source and a high stabilizing resistor.2. An improvement in thermal efficiency and jet temperature was made by constructing the upstream part of the anode nozzle with boron-nitride and increasing the distance between the cathode and the anode.3. As for the anode geometry, the performance of the plasma jets becomes high with the decrease of throat length, but the optimum value of throat diameter changes for the maxinum thermal efficiency and the maximum plasma jet temperature.

针对超燃冲压发动机燃烧室的点火和稳焰问题，提出了沿壁面形成电弧放电的方法（直接电弧放电法）。在直接电弧放电方法中，电弧放电产生的化学活性自由基比传统等离子体火炬更有效地利用。得到了以下结果：1。在超声速流动中，当阴极放置在上游，阳极放置在下游，与壁面平行时，通过阴极和阳极的间隙注入载气，直接电弧放电方法具有优异的点火和稳定火焰的能力。对于有壁台阶的情况，以上游表面为阴极，下游表面为阳极，并通过台阶底部的间隙注入载气的几何结构取得了成功的结果。燃料-空气混合物表现出作为载气的卓越能力。建立了高排气温度、高热效率的低功率等离子体射流（约100 W）的实验研究。通过对阴极和阳极之间的距离和阳极几何形状的详细检查，得到以下结果：采用高压电源和高稳定电阻相结合的方法，建立了常压下稳定运行的低功率氮等离子体射流。采用氮化硼构筑阳极喷嘴的上游部分，增加阴极与阳极之间的距离，提高了热效率和射流温度。在阳极几何形状上，随着喉道长度的减小，等离子体射流的性能提高，但最大热效率和最大等离子体射流温度的最佳值随着喉道直径的减小而变化。