Wall modeled large eddy simulation of supersonic flow physics over compression–expansion ramp Ebrahim Goshtasbi Rad n , Seyed Mahmood Mousavi School of Mechanical Engineering, Shiraz University, Shiraz 71348-51154, Iran article info Article history: Received 20 June 2015 Received in revised form 20 July 2015 Accepted 21 July 2015 Available online 14 August 2015 Keywords: Compression–expansion ramp WMLES Shock–turbulent boundary layer Control shock behavior abstract In the present work, wall modeled large-eddy simulation (WMLES) in the Fluent software is used to investigate the flow physics of a three-dimensional shock–turbulent boundary layer interaction, as an important phenomenon in aerospace science, on a compression– expansion ramp with the angle of 251. Fine flow structures are obtained via Laplacian of density that called shadowgraph, in which shock wave structures are visible distinctly. The results are compared with the experimental data of Zheltovodov et al., 1990 [33], in the same condition regarding geometry, boundary conditions, etc. as those used by them. Results show that not only there are a good agreement with experimental trends concerning wall pressure, friction coefficient distribution and mean velocity profiles, but also in comparison with those presented by Grilli et al., 2013 [24]. LES simulation, used in this study, presents more accurate results with fewer computational costs. Afterwards, we investigated the influence of discontinuity in wall temperature, varying stagnation pressure and Reynolds number on physics of flow in order to control the shock behavior. Our simulations shows that, discontinuity in wall temperature, varying free stream stagnation pressure and Reynolds number (the free stream Mach number remained essentially constant) influences the starting point of shock, shock strength, separation length and the collision angle of separated and reattachment shock waves. & 2015 IAA. Published by Elsevier Ltd. All rights reserved. 1. Introduction The recompression of supersonic gas flow is a very usual occurrence in modern aerodynamics [1]. Shock–turbulent boundary layer interaction (STBLI) is one of the most pre- valent physical phenomena in a variety of applications in aerospace science including supersonic and hypersonic trans- port, which can affect significantly the aero-thermodynamic loads [2]. Accordingly, the design process of supersonic and hypersonic air vehicles requires accurate investigation. There- fore, many experimental and numerical studies of STBLI in various configurations have been carried out over the past several decades. An experiment of hypersonic laminar and transitional flows in a compression corner was conducted to study the boundary layer separation; it was found that the extent of separation in transitional flow was reduced sig- nificantly in comparison to laminar flow [3]. An experiment was carried out by Settles et al. [4] to detail the influence produced by different deflection angles, and the character- istics of corresponding flow fields were described. Smits et al. [5] used hotwires to measure the longitudinal mass-flux fluctuations and the mass-weighted turbulent shear stress in compression ramp flows under different deflection angles. Based on planar laser Mie scattering, Chan et al. [6] researched the detailed structures of the incoming boundary layer and separation shock in a Mach 5 compression ramp; the results suggested that the incoming boundary layer was comprised of large-scale vortex structures, and the low- Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/actaastro Acta Astronautica http://dx.doi.org/10.1016/j.actaastro.2015.07.022 0094-5765/& 2015 IAA. Published by Elsevier Ltd. All rights reserved. n Corresponding author. E-mail address: goshtasb@shirazu.ac.ir (E. Goshtasbi Rad). Acta Astronautica 117 (2015) 197–208