论文标题
分层介质中湍流喷泉崩溃的扩散高度和关键条件
Spreading height and critical conditions for the collapse of turbulent fountains in stratified media
论文作者
论文摘要
分层环境中的轴对称喷泉升高，直到达到最大高度为止，垂直动量消失，然后在众所周知的顶级帽子剖面沿环形羽流掉落并径向扩散。首先，在这里，我们概括了Morton等人的模型。 （Proc。R.Soc。Lond。A\ TextBf {234}，1，1956），以正确确定最大高度和扩散高度的依赖性与所涉及的参数的依赖性。我们获得了喷泉崩溃的临界条件，即\ textit，即射流降至源水平时，并证明必须将扩散高度表示为至少两个参数的函数。为了改善实验的定量一致性，我们修改了标准以在下降流中考虑混合过程。实施数值模拟以估计表征该合并的参数值。我们表明，我们的广义模型与实验测量非常吻合。
Axisymmetric fountains in stratified environments rise until reaching a maximum height, where the vertical momentum vanishes, and then falls and spread radially as an annular plume following a well-known top-hat profile. Here, firstly, we generalize the model of Morton et al. (Proc. R. Soc. Lond. A \textbf{234}, 1, 1956), in order to correctly determine the dependence of the maximum height and the spreading height with the parameters involved. We obtain the critical conditions for the collapse of the fountain, \textit i.e. when the jet falls up to the source level, and show that the spreading height must be expressed as a function of at least two parameters. To improve the quantitative agreement with the experiments we modify the criterion to take the mixing process in the down flow into account. Numerical simulations were implemented to estimate the parameter values that characterizes this merging. We show that our generalized model agrees very well with the experimental measurements.
