| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1995: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1994: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Research Abstract |
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
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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
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