N. Abedimahzoon, A. Lashteh Neshaei,
Volume 11, Issue 4 (Transaction A: December 2013)
Abstract
In this paper, a new approach is presented for estimating the vertical and horizontal distribution of undertow in the surf
zone for reflective beaches. The present model is a modification of the original model presented by Okayasu et al., (1990) for
natural, non-reflective beaches to include the effect of partially reflected waves. The nonlinearity of waves, wave-current
interaction and nonlinear mass drift of the incident wave are also included in the present model. The results of experimental
investigation and model development show that existence of reflective conditions on beaches results in a reduction in the
magnitude of undertow and modifies its distribution across the beach profile. Comparison of the results by those obtained from
the experiments clearly indicates that by taking the nonlinearity and wave-current interaction, the predictions of undertow in
the surf zone are much improved. In particular, due to the effect of turbulence induced by wave breaking for nonlinear waves,
the predicted results show more consistence with the measurements.