ON FLOW CHARACTERISTICS OF A RECTANGULAR DE LAVAL NOZZLE WITH A LOW DENSITY GAS.

Effects of inlet gas density and pressure ratios on a discharge coefficient through a rectangular De Laval nozzle were studied. In the region of Reynolds number less than 2. 0 and Knudsen number greater than 1. 0, the discharge coefficient appeared to be nearly constant. The flow conductance of the nozzle was compared with free molecular flow theory. Flow characteristics with air or argon through the nozzle were measured and Mach number distributions on horizontal and vertical planes at the nozzle exit revealed. Furthermore, detached shock waves in front of a circular cylinder in a supersonic gas stream were visualized by a glow discharge technique. In this paper, shock detachment distances and pressure rises of the shock waves are compared with conventional data and theory.