REVISITING WAVE PROPAGATION UNDER AIR FLOW IN COASTAL AREAS

Abstract

The interaction between ocean waves and winds can be separated into two main analyses. A first interaction considers the wind as the primary wave generator. The mechanism through which wind exerts stresses to the water surface that combined with the gravity forces produce the surface oscillatory flow known as waves, is relatively well documented theoretically (Blennerhassett 1980), experimentally (Plate et al. 1969) and numerically (Liu et al. 2016). On the other hand, as waves travel to the coast, winds stop being the generating force and turn into an energy source travelling along with the waves. In places close to the shore, winds can be directed with or against the wave propagation. It is straightforward that wave properties close to the shore are modified under different wind conditions (Xie 2017). Numerical and experimental studies on wave-wind interaction near the coast and in presence of obstacles exist but are still scarce (Medina 2001). The present research is an experimental study of the perturbation produced by an air flow over waves in shallow waters and interacting with sloped obstacles. Well-known phenomena such as wave braking, steepening and run-up are revisited under wave-wind conditions.