水下管道局部冲刷平衡深度预测方法

Prediction of Equilibrium Scour Depth of Underwater Pipeline

为了更准确地预测水下管道局部冲刷平衡深度,提出了一种预测局部冲刷平衡深度的新方法,通过数值模拟手段,利用有限体积法来求解N-S方程和标准κ-ε方程,得到了冲刷平衡时的水下管道绕流场,进而分析了冲刷坑内过流量,通过数据拟合得到与冲刷坑深度有关的冲刷坑过流量经验公式,并应用基于该公式的冲刷平衡深度预测方法和已有方法对不同水流条件下冲刷坑深度进行了预测。结果表明,该方法预测结果与试验结果更接近,预测误差在20%以内,明显高于已有方法,为水下管道局部冲刷平衡深度预测提供了技术手段。

In order to predict the equilibrium scour depth of underwater pipeline more accurately, this paper presents a new method to predict the maximum clear-water scour depth below underwater pipeline. The flow fields around the pipeline over the equilibrium scoured beds are numerically simulated by solving Navier-Stokes equations and standard κ-ε turbulence model. The finite volume method is applied in the simulations. The flow discharges from the scour hole at va- rious conditions are studied and a fitting relation between the discharge from the scour hole and the maximum scour depth is obtained. Integrating this relation with the Colebrook-White equation, the scour depth is predicted. The results agree well with the measured values and the relative error is less than 20 %, which indicates that the proposed method is accu- rate for predicting the clear-water scour depth of underwater pipelines.