论文标题
改进的梯级溢洪道的空气夹带模型
An improved air entrainment model for stepped spillways
论文作者
论文摘要
考虑了跨溢洪道中流量的数值建模，重点是将界面捕获与空气夹带的显式建模相结合的高度经济的方法。模拟是在溢洪道上以四个不同的Froude编号进行的，其中选择了流参数以匹配可用的实验数据。首先，使用Lopes等人开发的模型的实验。 （Int。J.Nonlin。Sci。Num。，2017）。广泛的仿真运动用于仔细评估模型的预测准确性，各种模型参数的影响以及对电网分辨率的敏感性。结果表明，至少对于阶梯性溢洪道的情况，可以减少控制模型的参数的数量。该模型的关键缺陷是其对网格分辨率的敏感性。为了改善模型在这方面的性能，为接口检测算法和用于夹带空气的体积分数的传输方程提出了修改。使用改进的模型公式的模拟表明，对于所有考虑的流量条件，与参考数据具有更好的一致性。还测试了用于预测空气夹带开始点的无参数标准。不幸的是，事实证明，所考虑的常规湍流模型的准确性不足以可靠工作。
Numerical modelling of flow in stepped spillways is considered, focusing on a highly economical approach combining interface capturing with explicit modelling of air entrainment. Simulations are performed on spillways at four different Froude numbers, with flow parameters selected to match available experimental data. First, experiments using the model developed by Lopes et al. (Int. J. Nonlin. Sci. Num., 2017) are conducted. An extensive simulation campaign is used to carefully evaluate the predictive accuracy of the model, the influence of various model parameters, and sensitivity to grid resolution. Results reveal that, at least for the case of stepped spillways, the number of parameters governing the model can be reduced. A crucial identified deficiency of the model is its sensitivity to grid resolution. To improve the performance of the model in this respect, modifications are proposed for the interface detection algorithm and the transport equation for the volume fraction of entrained air. Simulations using the improved model formulation demonstrate better agreement with reference data for all considered flow conditions. A parameter-free criterion for predicting the inception point of air entrainment is also tested. Unfortunately, the accuracy of the considered conventional turbulence models proved to be insufficient for the criterion to work reliably.
