潮流作用下风电塔单桩基础冲刷数值模拟

Numerical Simulation on Scour around Monopile Foundation of Wind Turbine under Tidal Current

近海潮流的往复作用会造成近海风电塔单桩基础土体冲刷,影响风电塔性能,而目前的研究对于双向流下风电塔单桩基础的冲刷机理认识不清。本文考虑了流动变向,采用RNG湍流模型,根据水流作用下泥沙起动、搬运和沉积方程建立了双向流下单桩基础三维冲刷数值模型。将计算结果与蒋家沙单桩基础风电塔冲刷深度现场观测对比验证,在此基础上进行参数分析和冲刷深度公式推导。研究结果表明在流体变向后初期冲刷的作用表现为转移最大冲刷深度的位置,且本文提出的冲刷深度计算公式适合于计算双向流下近海单桩基础风电塔冲刷深度。

The reciprocating action of the offshore tidal flow takes away the soil around the monopile foundation of offshore wind turbine,which is harmful for wind turbine operation.However,the scouring mechanism around monopile foundation of offshore wind turbine under bidirectional flow is not clear in existing research.In this paper,considering the flow direction change,by RNG turbulence model and equations of sediment entrainment,transportation and deposition,a three-dimensional numerical model of scour around monopile foundation under bidirectional flow was established.The calculation results are verified by on-site measurement of the scouring depth around monopile foundation of wind turbine in Jiang Jiasha,and the parameter analysis and the scouring depth formula are derived on this basis.Results show that in the initial stage after the fluid is reversed,the effect of scouring is to shift the position of the maximum scouring depth.Moreover,formula proposed in this article is suitable for calculating the scouring depth of offshore monopile foundation wind turbine under bidirectional flow.