Review and Assessment of Turbulence Models for Hypersonic Flows: 2D/Asymmetric Cases

Abstract

Turbulence modeling remains a major source of uncertainty in the computational prediction of aerodynamic forces and heating for hypersonic vehicles. The first goal of this paper is to update the previous comprehensive review published in 1991 by Settles and Dodson (G. S. Settles and L. J. Dodson, “Hypersonic Shock/Boundary-Layer Interaction Database,” NASA CR 177577, April 1991). In their review, Settles and Dodson developed a methodology for assessing experiments appropriate for turbulence model validation and critically surveyed the existing hypersonic experimental database. We limit the scope of our current effort by considering only twodimensional/axisymmetric flows in the hypersonic speed regime where calorically perfect gas models are appropriate. We extend the prior database of recommended hypersonic experiments by adding three new cases. The first two cases, the flat plate/cylinder and the sharp cone, are canonical test cases which are amenable to theory-based correlations, and these correlations are discussed in detail. The third case added is the two-dimensional shock impinging on a flat plate boundary layer. The second goal is to review and assess the validation usage of various turbulence models on the existing experimental database. Here we limit the scope to one- and two-equation turbulence models where integration to the wall is used (i.e., we omit studies involving wall functions). In order to preserve a models prior validation history, we omitted corrections to the standard turbulence models in cases where the impact of such corrections on low-speed flows had not been adequately addressed (either through a re-validation of the models on a wide range of low-speed test cases or theoretical arguments). A methodology for validating turbulence models is given, and turbulence model comparisons from various authors are compiled and presented in graphical form. Conclusions are drawn for those models which have been applied to a sufficiently wide range of two-dimensional/axisymmetric hypersonic flows, and recommendations for future experimental and modeling efforts are given.