고도모사용 초음속디퓨져의 진공성능 및 천이작동특성

Effects of essential geometric and operating factors controlling steady evacuation performance and transient operating characteristics of a straight axi-symmetric supersonic exhaust diffuser (SED) with zerosecondary flows are studied experimentally and numerically. Pressure records along diffuser wall and in vacuum chamber are measured by a small-scale cold gas simulator using cold nitrogen gas as a working fluid. Preconditioned Favre-Averaged Navier-Stokes equations with low Reynolds number κ-e turbulence model edited for turbulence compressibility effects are employed to solve steady and unsteady diffuser flows.