ノズル内における高エンタルピー気流の電離特性に関する実験的考察

抄録

A study of ionization characteristics of high enthalpy nozzle flow has been carried out by using the arc-heated wind tunnel with conical nozzle, where argon gas is used for the simplicity of analyzing the phenomenon. In this experiment, the exit pressure is relatively low, so that the non-equilibrium flow can be realized. The electron temperature and electron number density are measured by Langmuir probes at three stations located on the nozzle surface for several stagnation temperatures. The test results are compared with the analysis using the frozen flow which is commonly treated in such a flow. As a result, the nonequilibrium flow with non-frozen flow characteristics were obtained near the nozzle surface. The experimental result of electron number density rapidly decreases toward the downstream unlike the analysis. On the other hand, the electron temperature showed good agreement with each other. Thus, the ionization characteristics were made clear near the nozzle surface.