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对文献中多个槽缝冲击射流的经典实验结果进行数值模拟,考察RNGk-ε和Transition SST湍流模型的表现,主要分析射流出口中心线和展向、壁面射流区域的雷诺时均速度和湍流度分布,以及靶面换热效果与流场模拟结果之间的关系.模拟结果表明,与Transition SST湍流模型相比,RNGk-ε模型的结果表现出更强的湍流粘性,使得其中心线上速度衰减较快,该效果可能导致低估靶面上的冲击换热效果?而在冲击滞止区域,RNGk-ε湍流模型结果表现出过高的湍动能,该效果可能导致高估靶面上的冲击换热效果.因此,当射流雷诺数较小时,Transition SST模型所得滞止区换热系数要高于RNGk-ε模型的结果,反之亦然;而在壁面射流区域,RNGk-ε模型对于流场速度的模拟较好,但相应区域的传热模拟并没有表现出明显的优越性.
The classical experimental results of multiple jets impact jets in the literature are numerically simulated to investigate the performance of the RNGk-ε and Transition SST turbulence models. The main points of the jet exit centerline and span, Renault hourly mean velocity and turbulence Distribution and the relationship between the heat transfer effect of the target surface and the simulation results of the flow field.The simulation results show that compared with the Transition SST turbulence model, the results of the RNGk-ε model show a stronger turbulent viscosity, making the centerline velocity This effect may lead to an underestimation of the impact of heat transfer on the target surface. In the area of impact stagnation, the RNGk-ε turbulence model results show excessive turbulent kinetic energy, which may lead to overestimation of impact on the target surface Therefore, when the Reynolds number of the jet is small, the heat transfer coefficient of the stagnation zone obtained by the Transition SST model is higher than that of the RNGk-ε model and vice versa, while for the wall jet region, the RNGk-ε model is better for the flow field The simulation of velocity is better, but the heat transfer simulation in the corresponding area does not show obvious superiority.