HFF 19,5 574 International Journal of Numerical Methods for Heat & Fluid Flow Vol. 19 No. 5, 2009 pp. 574-594 # Emerald Group Publishing Limited 0961-5539 DOI 10.1108/09615530910963535 Received 28 April 2007 Revised 9 April 2008 Accepted 21 April 2008 Non-equilibrium viscous shock-layer technique for computing hypersonic flow around blunt-nosed slender bodies S. Ghasemloo and M. Mani Center of Excellence in Computational Aerospace Engineering, Department of Aerospace Engineering, Amirkabir University of Technology, Tehran, Iran Abstract Purpose – The purpose of this paper is to present a non-equilibrium viscous shock layer (VSL) solution procedure that considerably improves computational efficiency, especially for long slender bodies. Design/methodology/approach – The VSL equations are solved in a shock oriented coordinate system. The method of solution is spatial marching, implicit, finite-difference technique, which includes coupling of the normal momentum and continuity equations. In the nose region, the shock shape is specified from an algebraic expression and corrected through global passes through that region. The shock shape is computed as part of the solution beyond the nose region and requires only a single global pass. For this study, a seven-species ðO 2 ; N 2 ; O; N ; NO; NO þ ; e  Þ air model is used. Findings – The present approach eliminates the need for initial shock shape, which was required by previous method of solution. This method generates its own shock shape as a part of solution and the input shock shape obtained from a different solution is not required. Therefore, in comparison with the other VSL methods, the present approach dramatically reduces the CPU time of calculations. Moreover, by using the shock oriented coordinate systems the junction point problem in sphere-cone configurations is solved. Practical implications – This method is an excellent tool for parametric study and preliminary design of hypersonic vehicles. Originality/value – The present method provides a computational capability which reduces the CPU time, and expands the range of application for the prediction of hypersonic heating rates. Keywords Aerodynamics, Heating, Viscosity, Equilibrium methods, Hypersonic flow Paper type Research paper The current issue and full text archive of this journal is available at www.emeraldinsight.com/0961-5539.htm Nomenclature c i ¼ mass fraction of species i, r i /r C p ¼ specific heat at constant pressure, C  P =C  P1 h ¼ static enthalpy, h  =V 2 1 h 1 ; h 3 ¼ metrics J i ¼ diffusion mass flux of species i, J  i R  n =m ref k ¼ thermal conductivity, k  =m  ref C  P1 k i;w ¼ surface reaction rate coefficient, k  i;w =V 1 L e ¼ Lewis number M ¼ Mach number M i ¼ molecular weight of species i n b ¼ Shock standoff distance N s ¼ number of reacting species p ¼ pressure, p  =&  1 V 2 1