Chun, H. and Suh, K.-D., 2016. Wave-induced Reynolds stress in three-dimensional nearshore currents model.
This paper presents the formulation of the wave-induced Reynolds stress (WIRS), i.e. the correlation of horizontal and vertical water particle velocities, based on the Airy's wave theory. Even though the correlation of the velocities is zero in a constant-depth water, it has a nonzero value if there are slopes on the bottom and mean water level. Comparison of the vertical gradient of the WIRS term with the horizontal gradient of wave-forcing terms shows that the two terms have the same order of magnitude, which in turn is comparable to that of the radiation stress in the surf zone. For the three-dimensional computation of nearshore currents, the WIRS term is incorporated into a three-dimensional ocean model in the σ coordinates. The numerical model is then applied to two laboratory experiments. To see the effect of the WIRS term on the mean flow, numerical simulations without this term are also carried out. The numerical simulations show that the WIRS term influences the flow properties such as mean water level, longshore current, and undertow.