Numerical simulation of supersonic flows with chemical reactions

The paper presents FDM solutions of the two-dimensional Navier-Stokes equations in a conservative-law form for supersonic flows with no reaction or H₂-air combustion. TVD schemes are employed in order to avoid numerical oscillation caused by discontinuities in the flowfield. By using the improved point implicit technique together with the automatic time step switching technique, the strong stiffness inherent to chemically reacting flow problems is successfully overcome. The computational code is applied to three types of geometrical configurations and flow conditions relevant to scramjet engines. The computational results well simulate such quite complicated flowfields including shock waves, expansions, boundary layers, and chemical reactions with high resolution. The present codes are proved to be robust and can be used routinely for analysis and design purposes. In the case of non-reacting, i.e., mixing flows, the numerical results are in good agreement with experimental Schlieren pictures.