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SUPPRESSION OF SHOCK/COMPRESSION WAVES IN SUPERSONIC CONFINED FLOW

超声速约束流中冲击/压缩波的抑制

基本信息

批准号：
06650194
负责人：
YAMASAKI Hiroyuki
金额：
$ 1.22万
依托单位：
TOKYO INSTITUTE OF TECHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1994
资助国家：
日本
起止时间：
1994 至 1995
项目状态：
已结题

项目摘要

An objective of the present research is to suppress shock waves and compression waves in a confined supersonic flow. In order to suppress these waves, an apply of electro-magnetic forces on the supersonic flow was proposed. In previous studies on shock waves done by many researchers, spatial structures and time behavior of shock waves were investigated. However, the suppression of them was not made. The present authors have proposed a new concept that shock waves may be suppressed by applying Lorentz forces on the supersonic flow, and experimental studies to confirm this concept were made using MHD channel. In order to obtain a sufficient electrical conductivity of the flow, argon seeded with cesium was used as a working gas. Lorentz forces were applied on the flow by applying a magnetic field, and electrical currents in the supersonic flow were controlled by load resistance between electrodes. It was found for the first time that the position of shock waves can be controlled by the ma … More gnitude of Lorentzforces and at the optimum Lorentz forces, the shock waves disappear within the MHD channel. Furthermore, the strength and the position of the shock waves were found to change with stagnation gas pressures. When the uniform distribution of the current was realized, the strength of the shock waves was decreased. In the present research, the controll of the shock wave in the MHD channel was also made by changing Lorentz forces in the nozzle which was located at the region upstream of the MHD channel. It was found that with an increase of the Lorentz forces in the nozzle, the shock waves in the MHD channel moved upstream and the strength of the shock waves was reduced. The pressure losses due to the apply of the Lorentz forces were also investigated. The results have shown that the pressure losses are induced mainly by a production of plasma and the loss due to the shock waves is small because an incident Mach number of the flow is reduced remarkably by Lorentz forces. These experimental results have suggested that the suppression of the shock waves in the supersonic flow by Lorentz force is possible and it is very attractive method from the engineering points of view. At the same time, the new knowledge of the magneto-hydrodynamics was obtained by the present research. Less

本研究的目的是抑制受限超音速流动中的激波和压缩波。为了抑制这些波动，提出了在超音速流动中施加电磁力的方法。在前人对冲击波的研究中，对冲击波的空间结构和时间行为进行了研究。然而，并没有对他们进行镇压。本文提出了通过对超音速流动施加洛伦兹力来抑制激波的新概念，并利用MHD通道进行了实验研究。为了获得足够的导电性，使用了掺入铯的Ar作为工作气体。通过施加磁场对流动施加洛伦兹力，超音速流动中的电流由电极之间的负载阻力控制。首次发现激波的位置可以通过ma…来控制。洛伦兹力越大，在最佳洛伦兹力作用下，激波在MHD通道内消失。此外，还发现激波的强度和位置随着滞止气体压力的变化而变化。当电流均匀分布时，冲击波强度减小。在本研究中，还通过改变位于MHD通道上游区域的喷管中的洛伦兹力来控制MHD通道中的激波。结果表明，随着喷管中洛伦兹力的增大，MHD通道中的激波向上游移动，激波强度减小。文中还研究了洛伦兹力作用下的压力损失。结果表明，压力损失主要是由等离子体的产生引起的，而激波损失很小，因为洛伦兹力显着降低了流动的入射马赫数。这些实验结果表明，洛伦兹力对超音速流动中激波的抑制是可能的，从工程角度来看，这是一种非常有吸引力的方法。同时，对磁流体力学也有了新的认识。较少