高速ミスト流中に発生する斜め衝撃波に関する研究(流体工学,流体機械)  [in Japanese] Oblique Shock Waves in High-Speed Mist Flow(Fluids Engineering)  [in Japanese]

High-speed two-phase mist flow is very important in developing the ejector of a refrigeration cycle and in the total-flow system of a geothermal power plant. Two types of sound speed in two-phase flow can be created because of the inter-phase transport phenomenon. One is equilibrium sound speed in which the inter-phase transport in the flow is in complete equilibrium. Whereas, the other one is frozen sound speed in which the inter-phase transport is completely frozen. Usually, the fluid velocity is higher than the equilibrium sound speed but lower than the frozen sound speed because the equilibrium sound speed is very low. The existence of the supersonic oblique shock waves is not certain because the fundamental equations of two-phase flow are controlled by the frozen sound speed. This paper shows that the oblique shock wave could appear at some conditions even though the frozen Mach number was less than unity. As the reference length became bigger, the inclined angle of the oblique shock wave reduced to the angle of the equilibrium one. The thickness of a shock wave is directly proportional to the product of the relaxation time and the inlet velocity. Then, the fronts of the shock waves for large relaxation times reached up the inlet. All of the flow area corresponded to subsonic state and the oblique shock wave could not exist anymore.