Abstract:
A threedimensional (3D) numerical model for nearshore waveinduced currents is established,in which the phaseaveraged 3D residual momentum flux,surface roller and wave turbulence are introduced as driving forces,and the wavecurrent combined bottom shear stress is taken into account.An energy balance equation of the surface roller is derived,considering the bottom slope,energy transmission rate and roller density.The LarsonKraus formula for the 2D wave turbulent mixing coefficient is extended to its 3D form.A number of experimental cases are used to validate the model,including the wave setup/setdown (1D),undertow (2-DV),longshore current (Q3-D),rip current (2-DH) and the circulation behind a detached breakwater (2-DH).The validation results show that the model is able to effectively describe the waveinduced current phenomena of various dimensions,and the incorporation of the surface roller is mandatory.The uniformity of the longshore current speed profile in the surfzone is related to the vertical turbulent mixing in the effect of waves.