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Highly Reliable Plasma Igniter for Ram/Scramjet

用于冲压/超燃冲压发动机的高度可靠的等离子点火器

基本信息

批准号：
10555331
负责人：
MASUYA Goro
金额：
$ 8.51万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-10555331/
关键词：
Scramjet Supersonic Combustion Ignition Plasma Jet 着火・保炎

项目摘要

In order to realize the ramjet/scramjet engine which is one of the most promising candidates of the propulsion system of aerospace planes, reliable ignition of fuel in supersonic airstream is an important subject. Plasma torches have been developed and tested in direct-connect combustors as well as in a sub-scale engine. However, early results of these tests showed insuffficient durability and reliability of the plasma igniter. The present research project has been carried out to clarify the cause of malfunction of the igniter and to develop highly reliable plasma igniter with experimental, theoretical and numerical approaches.The feedstock of the torch was changed from oxygen to nitrogen. Detrition of the electrodes and the nozzle of the torch was significantly suppressed by this change. In addition, the coolant of the torch was changed from gas to water. This change lessened thermal load of the torch. Durability of the plasma torch was greatly improved by these changes.Experimental and theoretical studies confirmed that the ignition performance of the nitrogen torch was as good as that of the oxygen torch. Improvement of the ignition perfomance was achieved by use of nitrogen/hydrogen mixture as the feedstock, though the minimum input power for the torch was increased. The improvement of ignition perfomance was caused by combustion of hydrogen in the plasma jet.When fuel was injected upstream the plasma torch, experiment and numerical simulation showed that it is important to select the lateral and transverse locations of the injector to make collision of the fuel jet and the plasma jet. The streamwise location and the angle of injection showed minor influence. When the fuel was injected downstream the plasma torch, the streamwise location became important, too.Increase of airstream Mach number made ignition performance of the torch worse. The effect of the pressue of the airstream was not straight forward in the present experiment.

为了实现冲压发动机/超燃冲压发动机作为空天飞机推进系统最有希望的候选者之一，超音速气流中燃料的可靠点火是一个重要的课题。等离子炬已在直连燃烧室和小型发动机中进行了开发和测试。然而，这些测试的早期结果表明等离子点火器的耐用性和可靠性不足。本研究项目旨在通过实验、理论和数值方法来阐明点火器故障的原因并开发高可靠性的等离子点火器。火炬的原料由氧气改为氮气。这一变化显着抑制了焊炬电极和喷嘴的磨损。此外，割炬的冷却剂也从气体改为水。这一变化减轻了割炬的热负荷。这些变化极大地提高了等离子炬的耐用性。实验和理论研究证实，氮气炬的点火性能与氧气炬的点火性能一样好。尽管增加了火炬的最小输入功率，但通过使用氮/氢混合物作为原料实现了点火性能的改进。点火性能的提高是由氢在等离子射流中燃烧引起的。当燃料在等离子炬上游喷射时，实验和数值模拟表明，选择喷射器的横向和横向位置对于使燃料射流与等离子射流碰撞非常重要。流向位置和喷射角度的影响较小。当燃料从等离子炬下游喷射时，流向位置也变得很重要。气流马赫数的增加使炬的点火性能变差。在本实验中，气流压力的影响并不是直接的。