Three-dimensional unstructured modelling of wave-induced circulation over a plane and irregular beach  

作　　者：汪求顺 康海贵 王科 

机构地区：[1]Zhejiang Institute of Hydraulics and Estuary, Hangzhou 310020, China [2]State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 116024, China [3]State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116024, China

出　　处：《Journal of Hydrodynamics》2016年第2期219-226,共8页水动力学研究与进展B辑（英文版）

基　　金：supported by the National Key Basic Research Development Program of China(973 Program,Grant No.2013CB036101);the National Natural Science Foundation of China(Grant No.51379037)

摘　　要：Nearshore currents have a complicated circulation structure over a beach due to the mutual interaction between waves and currents. To investigate the wave-induced circulation over a beach, a three-dimensional unstructured model accounting for the combined actions of waves and currents is established. The wave distribution over the beach is computed by a wave model and the depth-dependent wave radiation stresses with the surface roller are employed in the hydrodynamic model. The present model takes the mixing coefficients and the bottom shear stress under waves and currents into account. To evaluate the three-dimensional unstructured model, the laboratory experiments over a plane and irregular beach are used to test the performance of the model. The undertow over a plane beach is well reproduced and the vertical variability is captured. The performance of the model over an irregular beach is well displayed in the reproduction of pairs of cotmter-rotating primary circulations at the embayment troughs. Meanwhile, the secondary circulations are observed in the swash zone. The model captures the circulation systems over a beach and the circulation structures of the wave-induced currents are well exhibited.Nearshore currents have a complicated circulation structure over a beach due to the mutual interaction between waves and currents. To investigate the wave-induced circulation over a beach, a three-dimensional unstructured model accounting for the combined actions of waves and currents is established. The wave distribution over the beach is computed by a wave model and the depth-dependent wave radiation stresses with the surface roller are employed in the hydrodynamic model. The present model takes the mixing coefficients and the bottom shear stress under waves and currents into account. To evaluate the three-dimensional unstructured model, the laboratory experiments over a plane and irregular beach are used to test the performance of the model. The undertow over a plane beach is well reproduced and the vertical variability is captured. The performance of the model over an irregular beach is well displayed in the reproduction of pairs of cotmter-rotating primary circulations at the embayment troughs. Meanwhile, the secondary circulations are observed in the swash zone. The model captures the circulation systems over a beach and the circulation structures of the wave-induced currents are well exhibited.

关 键 词：unstructured model wave-induced currents depth-dependent wave stress circulation structures 

分 类 号：P731.2[天文地球—海洋科学]