Euler calculations of diffuser flow field, free jets and impinging jets

Under- and over-expanded jet flows are calculated for the Euler equations. The solution procedure is based on the two-stage Runge-Kutta time-stepping scheme. The studies of the flow field structure in diffusers, free jets and impinging jets have been investigated for a range of jet-to-stream total pressure ratios and for different exit Mach numbers. The resulting flows show a complex shock-shear expansion structure with Mach discs. Numerical results are compared with available experimental data and with previously published data. An oscillating phenomenon was observed in the case of free jets operating at sonic exit Mach number and in another case of impingement of under-expanded jets on a flat plate.