Study of supersonic bubble flow

Experimental and theoretical studies were made on the two-phase (air and water) supersonic bubble flow. To measure the bubble volume ratio and the bubble velocity, a two-electrode probe was used, and its signal was statistically analyzed. The principle, structure, and characteristics of the measuring system are presented. The probe was placed in a supersonic nozzle, whose diameter at the throat was 4.5 mm. The distributions of static pressure, bubble volume ratio, and velocity were measured along the central axis of the nozzle. The radial distribution of the bubble volume ratio was also measured at 45 mm and 50 mm down stream from the throat. A flow model was made for the high speed two-phase flow, and the basic equations were solved. The results of measurement were compared with the solution. It is concluded that the accuracy of the electrode probe measurement is within 5%, and that the equilibrium theory is well applicable for supersonic bubble flow. (Aoki, K.)