Introduction
The rearward facing step with a sharp corner is a classical configuration for studying separated flows. This configuration is also of practical relevance in a hypersonic vehicle. However, a truly sharp corner is basically a mathematical simplicity [9]. The influence of finite radius at the corner is therefore of significance and is studied here numerically under high enthalpy conditions using state-of-the-art computational fluid dynamics (CFD). The flow conditions are comparable to reentry velocity of 6.7 km/s which corresponds to a total specific enthalpy of h o ≈ 26 MJ/kg with a unit Reynolds number 1.82×106 per meter and a Mach number M ∞ ≈ 7.6 with air as the test gas. The geometry consists of an upstream flat-plate of length (L) of 48.4 mm with sharp leading edge. This is followed by a step of height (h) 2 mm and then a downstream flat plate of length (D) of 109.4 mm. Three different radii, r/h = 1/8, r/h = 1/3 and r/h = 1/1 are considered here for the corner radius. The two-dimensional flow-field of interest is modelled using a time-dependent Multi-Block Compressible Navier-Stokes (MB-CNS) solver [6]. Perfect gas calculations were made with air to behave as a single species and real gas calculations were made assuming air to be a mixture of thermally perfect gas with 5 neutral species and adopting Gupta’s kinetic scheme for chemical reactions [3]. A multi-block structured grid with 52,000 cells is used. This was arrived at after performing a grid independence study over a sharp corner and modifying the grid topology to suit the curvature for the rounded configurations. Details regarding grid convergence are given in Deepak [1].
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Deepak, N.R.: Computational Studies of Hypersonic High Enthalpy Separated Flows. PhD thesis, School of Engineering & IT, University of New South Wales, Canberra, Australia (Submitted November 2010)
Goldstein, S.: On laminar boundary-layer flow near a position of separation. Quart. J. Mech. Applied Math. 1, 43–69 (1948)
Gupta, R.N., Yos, J.M., Thompson, R.A., Lee, K.-P.: A review of reaction rates and thermodynamic and transport properties for an 11-species air model for chemical and thermal nonequilibrium calculations to 30 000 k, Technical Report 1232, NASA (1990)
Hama, F.R.: Experimental studies on the lip shock. AIAA Journal 6(2), 212–219 (1968)
Hollis, B.R.: Experimental and Computational Aerothermodynamics of a Mars Entry Vehicle. PhD thesis, Aerospace Engineering, North Carolina State University, Raleigh, North Carolina, USA (1996)
Jacobs, P.A.: Mb-cns: a computer program for the simulation of transient compressible flows. Technical Report 7/98, Department of Mechanical Engineering, University of Queensland, Brisbane (1998)
O’ Byrne, S.: Hypersonic Laminar Boundary Layers and Near-Wake Flows. PhD thesis, The Australian National University, Canberra (2002)
Stewartson, K.: On the flow near the trailing edge of a flat plate. Proc. Roy. Soc. A. 306(1486), 275–290 (1968)
Weinbaum, S.: On the singular points in the laminar two-dimensional near wake flow field. Journal of Fluid Mechanics 33(1), 39–63 (1968)
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Deepak, N.R., Gai, S.L., Neely, A.J. (2012). A Numerical Study of High Enthalpy Flow over a Rearward Facing Step with Rounded Corners. In: Kontis, K. (eds) 28th International Symposium on Shock Waves. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-25685-1_37
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DOI: https://doi.org/10.1007/978-3-642-25685-1_37
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