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. © 2007, DESIDOC.