URANS study of pulsed hydrogen jet characteristics and mixing enhancement in supersonic crossflow

In this paper, three-dimensional pulsed hydrogen jet in supersonic crossflow (PJISC) is investigated by the unsteady Reynolds Averaged Navier-Stokes (URANS) simulations with the k-omega shear stress transport (SST) turbulence model. The numerical validation and mesh resolution have been carried out against experiment firstly. The effects of the pulsed frequency and amplitude on the jet flow field and mixing performance in supersonic cross flow are all addressed. It significantly changes the distribution of the hydrogen jet flow by comparing with the steady jet in supersonic crossflow. The fuel jet penetration, mixing efficiency, decay rate of the maximum hydrogen mass fraction and total pressure losses are used to quantitatively analyze the mixing performance. The mixing of fuel and incoming air flow is enhanced by the pulsed jet, especially for the case of 50 kHz, which is the optimal pulsed frequency while considering the effects of jet excitation frequency in the present simulations. The decay rate of the maximum mass fraction of hydrogen in the far field downstream is related to the frequency of the pulse jet. Moreover, the pulsed frequency and amplitude have little effects on the total pressure recovery coefficient for the cases studied in the present simulations. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.