Comparison of the mixing efficiency of different injector configurations

Abstract The mixing efficiency of two injector configurations, one with a plane geometry and one with a streamwise-ramp geometry, is compared. The dense precursor gas tetraethoxysilane (TEOS – Si ( C 2 H 5 0 ) 4 ) is premixed with nitrogen and ejected through circular holes in the base of each injector into the nozzle flow at a co-flow Mach number of Ma co - flow ≈ 0.66 and a temperature of T co - flow ≈ 1200 K . Immediately downstream of the blunt trailing edge of the injector the flow field is accelerated to supersonic speed. The mixing process is determined by a multi-species large-eddy simulation (LES). The analysis shows a higher mixing efficiency of the streamwise ramp configuration against the plane geometry. Especially the temporal homogeneity is improved as a result of reduced vortex shedding at the injector base.