Numerical simulation of viscous flowfield in a scrafed reversal nozzle

Many solid propellent motors use a set of scrafed reversal nozzles located on the forward of the motors to provide reversal thrust during staging. Because the gasdynamic contour of reversal nozzle is not smooth and has a step in supersonic flow region, a series of shocks and flows separation in boundary-layer exists in flowfield of reversal nozzle. The viscous flowfields in scrafed reversal nozzle are simulated based on Renolds-average unsteady Navier-Stokes equations, with time-dependent method, MacCormack explicit scheme and Baldwin-Lomax algebraical turbulent model. The pressure distributions obtained from computation are in good agreement with experimental data.