A good injection strategy with high penetration and mixing efficiency relates to the overall performance of the airbreathing hypersonic propulsion system. In the current study, the transverse injection flow field with a vortex generator placed in front of jet has been investigated, and the jet mixing enhancement and penetration improvement induced by the pulsed jet has been evaluated as well. The obtained results predicted by the three-dimensional Reynolds-average Navier - Stokes (RANS) equations coupled with the two equation k-omega shear stress transport (SST) turbulence model show that the jet-to-crossflow pressure ratio has an great impact on penetration depth and mixing efficiency in the steady jet flow field. In the case of lower jet-to-crossflow pressure ratio, higher mixing efficiency but lower penetration depth are shown. On the other hand, compared with the steady jet flow field, the pulsed jet flow field with the periodic variation of jet-to-crossflow pressure ratio of the fuel injection has better comprehensive performance, and the penetration depth and mixing efficiency are improved simultaneously. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.