Turbulent Flow in Supersonic and Hypersonic Nozzles

摘要

The calculated turbulent flow properties in a supersonic or a hypersonic wind-tunnel nozzle are affected by the location of laminar-turbulent transition point and the behavior of the particular turbulence models considered. These effects are studied numerically by solving Reynolds-averaged Navier-Stolces equations for two nozzles. Results are reported using either an algebraic turbulence model or two alternative k-e models in which one contains two kinds of explicit compressibility corrections. The numerical method is based on a finite volume technique using a space centered Runge-Kutta scheme which is explicit to the mean flow equations and semi-implicit to the k and 6 equations. These calculations provide us a better understanding of the mechanism controlling this kind of flowfield. It is found that a small variation of transition point in near throat region has substantial global effects on the computed results downstream. Including explicit compressibility corrections in modeling the hypersonic nozzle flow introduces nonnegligible effects into the solution and improves its accuracy. The turbulence transport effects are also demonstrated.