磨刀门河口枯季波生流场数值模拟研究

The numerical investigation of wave induced current in the dry season in the Modaomen estuary

本文建立曲线坐标系下的双曲型缓坡方程波浪模型和考虑波浪辐射应力影响的深度平均2D潮流数学模型,首次研究了磨刀门河口2011年地形条件下的枯季波生流场。受波浪作用影响,落潮阶段,波浪作用方向与流向相反,在波浪顶托效应下拦门沙沙脊及外坡处流速普遍减小,形成两个主要回流区,口门外东西两侧浅滩处流速也减小,东西两汊及横洲深槽流速增大;涨潮阶段,波浪作用方向与流向相同,拦门沙沙脊及外坡处流速增大,沙脊处出现冲越流,口门两侧浅滩处流速增大,横洲深槽流速减小。

A hyperbolic mild-slope equation wave propagation model was united with a depth-averaged 2Dtidal flow model and the wave effect on flow is generated by radiation stresses of waves added to the tidal flow model.The wave induced current in the Modaomen estuary in the dry season was investigated for the first time by the model with the topography measured in 2011.The numerical results show that during the ebb tide the seaward currents are reduced by the opposing wave and two stagnant zones arise inside the shoaling water of the mouth bar,the seaward currents in east and west shoals also decrease,but the seaward currents inside the east and west deep grooves increase.During the flood tide the landward currents are increased by the following wave and a washover zone arise inside the mouth bar,the landward currents in east and west shoals also increase,but the landward currents inside the east and west deep grooves reduce at the same time.