Rapid engineering approach to modeling hypersonic laminar-to-turbulent transitional flows

Modeling the transitional behavior of hypersonic flows from an engineering point of view is addressed. More specifically, the accuracy of transition onset predictions by using a modified transition onset transport model is examined. Transitional blending is predicted by using the well-established Dhawan and Narasimha algebraic model. To employ the rapid engineering approach, the methodology is encompassed within the So, Sarkar, Gerodimos, and Zhang low-Reynolds-number k-epsilon turbulence model framework that has been extended to include compressibility effects. Model calibration and validation is achieved by using fundamental flat-plate data sets of Mee as well as recent data sets obtained by Holden for scramjet forebody geometries. It is shown that the transition onset transport equation predicts onset in accord with experimental values by using freestream velocity fluctuation levels consistent with those of the shock tunnel facilities. An additional simulation of the reentry F vehicle under low noise flight conditions was also performed. Under these conditions, the onset model predicts the location of transition very close to that measured. Overall, the framework developed can be used for very rapid turnaround engineering applications. The model can account for both freestream noise as well as amplification effects caused by shock/boundary interactions, specifically those dealing with compression corners.