带协同流壁面射流的数值模拟模型及影响规律

针对下击暴流中的壁面射流模型，采用4种不同湍流模型的CFD方法比较分析了带协同流壁面射流在不同发展阶段的平均风剖面及雷诺应力等流场特性.结果表明，使用修正的雷诺应力模型（RSM）得到了与实验较为吻合的结果，对带协同流壁面射流的数值模拟是有效和准确的.使用修正的RSM分析了不同协同流和射流风速比β对壁面射流平均风剖面、壁面摩擦因数等参数的影响.分析结果显示：当β值从0.1增大到0.3时，相同位置处的速度越大，最大速度衰减越慢，壁面摩擦因数减小越快，内、外层相互作用越弱.
For wall jet model with co-flow used in the downburst, four turbulent models were used to analyze the flow characteristics of the wall jet with co-flow, including the average wind velocity profile and Reynolds stress at different developing stages. The results show that the prediction of the modified Reynolds stress model (RSM) is in close agreement with the experimental data. The modified RSM is effective and accurate for the wall jet with co-flow, and it is also used to investigate the effects of ratio of the wall jet bulk velocity and co-flow velocity on the wall friction coefficient and mean wind velocity profile. It is found that when β increases from 0.1 to 0.3, the mean velocity increases with the velocity ratio, the maximum velocity degradation becomes slower gradually, the wall friction coefficient decreases more rapidly, and the interaction between inner layer and outer layer is decreased.