Numerical analysis of a plane, chemically reacting, supersonic jet flow using a time-dependent method

The evolution in time for a 2-dimensional, supersonic jet in chemical nonequilibrium is computed. The calculation starts with the emergence of the flow at the outlet and runs until the jet has formed completely. The numerical model includes the laminar, inviscid flow equations and the chemical kinetics. A time-step splitting technique is used to account for the different time scales characteristic of the fluid and chemical processes. The fluid dynamic equations are solved by an explicit scheme. The chemical source terms occuring for species and energy are approximated by averaged integral values. The averaged source terms result from a separate integration of the chemical rate equations along discrete particle path segments using an implicit method. The boundaries of the investigated flow occur in the form of a solid wall and a precursor shock wave. The condition at the wall is satisfied by a postcorrection method. The precursor shock wave is treated by a shock-fitting procedure. Results are discussed for a jet consisting of a reactive hydrogen-air mixture. Several graphs show the evolution of the flow by distributions of velocity vectors, pressure, temperature, Mach number and chemical species. The results for the reacting flow, compared to those for the frozen flow show the influence of the chemical energy released.