Analysis of Gain Coefficients for CO2-N2-He Nozzle Flows with Boundary Layer

Abstract

Experimental measurements and theoretical calculation of gain coefficients were made for vibrationally nonequilibrium nozzle flows, with relatively low reservoir pressure. A simple and semi-empirical method to estimate the effective cross section of the expansion core was proposed and applied to the calculations. Gain coefficients versus the reservoir pressure, throat height, and the distance along a nozzle were measured. Experimental results agreed well with the theoretical ones.