고도모사용 2차목 디퓨져 시동을 위한 디퓨져 팽창비 설계기법에 관한 연구

Starting characteristics of the axi-symmetric second throat exhaust diffuser (STED) with zero-secondary flows are numerically investigated. Renolds-Average Navier-Stokes equations with a standard κ-e turbulence model incorporated with enhanced wall treatment are solved to simulate the diffusing evolutions of the nozzle plume. Minimum (optimum) starting pressure difference of 20~25% between 1-D theory and the measured data validated from previous results[5] is also applied to predict the range of an effective diffuser expansion ratio (Ad/At) in this system.