波浪驱动下的近岸流数值模拟

Numerical Simulation of Wave- induced Nearshore Currents

波生沿岸流是近岸流场结构中的重要组成部分,也是近岸泥沙搬运和水环境输移的重要动力因素。建立了基于波浪辐射应力的平面二维波浪潮流数学模型,采用近似黎曼解的Roe格式有限体积法对模型求解。通过对概化模型试验不同波浪入射下的沿岸流模拟,并与已有模型成果对比,验证了模型应用的广泛性和正确性。重点分析了不同潮滩坡降对沿岸流的影响,并得到沿岸流的一般规律性认识。结果表明,岸坡越陡,近岸沿岸流越大,水位波动也越大,缓坡上波生沿岸流影响的范围明显大于陡坡。

Wave- induced coastal currents are an important part of nearshore flow field structure, and a major dynamic factor of nearshore sediment and water transport. This paper established a wave - radiation - stress - based 2D mathematical model of water cunrrents, and solved the model by Roe＇ s Scheme Finite Volume Method similar to Riemann solutions. Through simulation of coastal currents with different incident waves in generalized model experiments and comparison between the results and other existing model results, the study verified the extensiveness and correctness of this model application. The paper analyzed the influences of different tidal fiat gradients on coastal currents and reached a general understanding of rules. Results show that the steeperthe slope, the larger the nearshore currents and the larger the fluctuations of water levels. Wave- induced eoastal currents in mild slopes have a significantly wider scope of influence than that in steep slopes.