【摘要】 对脉冲激励的超声速横向氢气射流混合过程进行三维非稳态雷诺平均(URANS)模拟,湍流模型为k-w SST模型。与无激励措施的混合结果相比,燃料射流喷口下游增加脉冲激励会强化流场中大尺度结构如反向涡对(CVP)与涡对(TCVP),进而增强射流与主流的混合过程。射流穿透深度、混合效率以及总压损失的计算结果表明:当脉冲频率为50 k Hz时,能够更好地提高射流的混合效率;增大脉冲幅值可以明显地增强氢气与空气混合进程,同时总压损失未受脉冲扰动的影响而增加。更多还原

【Abstract】 Three-dimensional supersonic transverse jet mixing with pulsed excitation was investigated by using the unsteady Reynolds Averaged Navier-Stokes( URANS) simulations with the k-w SST turbulence model. Compared with the results of steady jet mixing,pulsed excitation in the downstream of fuel jet nozzle will affect the large scale structure of flow field,such as counter-rotating vortices pair( CVP) and trailing counter-rotating vortex pair( TCVP),and therefore,enhance the mixing process between the fuel jet and incoming air flow. The fuel jet penetration,mixing efficiency and total pressure losses are used to quantitatively analyze the mixing performance. The mixing efficiency between fuel jet and incoming air flow is obviously improved at 50 k Hz pulsed frequency. The mixing process of hydrogen and air is enhanced with increasing pulsed amplitude,while the total pressure loss is not affected by the pulse disturbance.更多还原