Amjad A. Pasha , Khalid A. Juhany
DOI Number XXX-YYY-ZZZ
Conference Number HiSST 2018_38501137
A hypersonic vehicle during its complete flight regime encounters a wide range of conditions. These flight conditions may vary from low to high Mach numbers at variety of angles of attack. The surface wall temperatures associated with high Reynolds flows lead to heat transfer and wall shear stress issues. The resulting flow separation, often associated with shock wave/boundary layer interactions, generally leads to increased energy losses in the system and degrades the performance of such aerodynamic control surfaces such as the fins installed on the vehicle. Reynolds-averaged NavierStokes equations using standard turbulence models result in incorrect separation bubble size for large separated flows. This results in inaccurate aerodynamic loads such as the wall pressure, local skin friction distribution and heat transfer rate. In the former studies, the shock-unsteadiness correction was applied to the standard two-equation k-w model which improved the separation bubble size leading to more accurate pressure predictions and the shock definition. In this work, a shock unsteadiness modification to k-w model is applied to the hypersonic flows, based on a parameter which is dependent upon the local strength of the shock wave subjected to upstream turbulent boundary layer fluctuations. Compression corner flows with different deflection angles q ranging from 15o to 38o at Mach 9.22 are simulated first. This is followed by further simulations where free stream Mach numbers are varied from M∞ = 5 to 9. A separate study is conducted to assess the effect of cool and hot temperatures Tw under isothermal surface conditions. Reynolds number effects will also be investigated where the boundary layer based Red is varied from 1×105 to 4×105 .The ramifications of q, M∞, Tw and Red upon surface pressure, skin friction and heat transfer rates, particularly in the interaction region, forms the basic theme of this research.