Total Pressure Loss in a Supersonic Nozzle Flow with Condensation

凝縮을 隨伴하는 超音速 노즐흐름의 全壓損失

A rapid expansion of moist air or steam in a supersonic nozzle gives rise to condensation, and the total pressure of the flow is decreased due to this irreversibility of condensation phenomenon. In the present paper, the loss in total pressure during the condensation process has been studied, by numerical analysis and pressure measurement, in the case of moist air expanding in a supersonic nozzle. The effects of the degree of supersaturation at the stagnation condition and expansion rate of the nozzle on the total pressure loss have been studied. The length of the region where the total pressure decreases during the condensation process is longer than that of the nonequilibrium condensation region, and of difference between the length of these two increases with the increase of the degree of supersaturation at the stagnation condition. Furthermore, the larger the expansion rate of the nozzle and the higher the temperature and the degree of supersaturation at the reservoir are, the larger the total pressure loss of the flow becomes. And, it is turned out that the total pressure loss be about 2 to 8 percent in the present study.

본 연구에서는 작동유체로서 습공기를 사용하였을때 수반되는 응축에 의한 전 압손실을 실험과 수치해석을 통하여 정체점에 있어서의 습공기의 온도, 과포화도 및 노즐 팽창율의 효과와 액적 질량비 (g)과의 관계로서 구명하였다.