Defence Science Journal, Vol. 57, No. 4, July 2007, pp. 367-379 2007, DESIDOC Revised 13 April 2006 Numerical Modelling of Scramjet Combustor M. Deepu 1 , S.S. Gokhale 2 , and S. Jayaraj 3 1 N.S.S. College of Engineering, Palakkad, Kerala–678 008 2 Indian Institute of Technology Madras, Chennai–600 036 3 National Institute of Technology, Calicut, Kerala–673 601 ABSTRACT Numerical modelling of turbulent-reacting flow field of supersonic combustion ramjet (scramjet) combustors are presented. The developed numerical procedure is based on the implicit treatment of chemical source terms by preconditioning and solved along with unstedy turbulent Navier-Stokes equations explicitly. Reaction is modelled using an eight-step hydrogen-air chemistry. Code is validated against a standard wall jet experimental data and is successfully used to model the turbulent-reacting flow field resulting due to the combustion of hydrogen injected from diamond-shaped strut and also in the wake region of wedge-shaped strut placed in the heated supersonic airstream. The analysis could demonstrate the effect of interaction of oblique shock wave with a supersonic stream of hydrogen in its (fuel-air) mixing and reaction for strut-based scramjet combustors. Keywords: Scramjet, strut injector, supersonic combustor, reduced chemistry, point implicit method, FVM NOMENCLATURE c Sound velocity C Chemical species Cv Specific heat at constant volume C p Specific heat at constant pressure D Effective exchange coefficient E Total energy F & G Flux vectors f Stochiometric hydrogen-air mass ratio Kinetic energy of turbulence k f Forward reaction rate k b Backward reaction rate K Thermal conductivity p Pressure Q Heat flux S Chemical source term U Vector of conservation variables u Velocity in x-direction v Velocity in y-direction Molecularity of a reaction Density Kinetic energy dissipation 367