Boundary-layer transition under the effect of compressibility for the correlation Based Transition Model

Abstract

Recently introduced ?-Re? correlation-based turbulence model is extended to account for compressibility effects on the boundary layer transition up to supersonic speeds. Firstly, empirical correlations used in the present model are further refined for low Mach numbers and validated against Schubauer & Klebanoff and ERCOFTAC T3 flat plate experiments. Secondly, a compressibility factor is added into the correlations and tested against the ERCOFTAC T3A- flat plate test case for the bypass transition regime. Due to lack of detailed experimental data in high Mach numbers, comparison was made in a generic way using the T3A- flat plate test case as the baseline. In this way, freestream turbulence level for the low subsonic T3A- case was kept constant, while changing the Mach number up to a low supersonic speed of Mach 1.2. Numerical results are compared against some recent theoretical transition predictions based on the linear stability theory. Results show that the extended ?-Re? correlation-based turbulence model is capable of predicting downstream movement of the transition onset location in good agreement with the linear stability theory. The extent of transition region is also observed to grow with the new correlation formula in qualitative agreement with experiment. Copyright © 2008 by the American Institute of Aeronautics and Astronautics, Inc.