An experimental study was presented in this paper to provide new information on the plunging breaking and on the flow properties at the impact of the plunging jet. Experiments were carried out using the image processes technique. The rate of energy dissipation and air penetration into the flow were estimated. A correlation between wave energy dissipation and two phase structure was found.
Waves may break as a consequence of various factors, but when breakwaters and pipelines, and sediment movements are considered one as most often concerned with breaking due to shoaling as waves approach shore. Notable progress has been made regarding our understanding "of the anatomy of breaking waves. However, the breaking process itself is still a considerably difficult problem. Several researchers have been interested in the description of wave breaking. However, general understanding of the mechanism and governing equations of the mean flow fields in water waves just breaking still"remains one of the unsolved problems in fluid mechanics (Basco, 1985). The proposed work is focused on this area, because it is of significance to coastal and offshore engineers as plunging breaking waves are the most severe environmental load on coastal and offshore structures. Iversen (1951) studied in the laboratory to determine the geometry and kinematics of breakers for various initial periodic wave conditions and for various beach slopes. Galvin (1968,1969) defined an offshore parameter or an inshore parameter for breaker type classification and gave the relation for travel distance of breakers. Peregrine (1979, 1980) contributed to the mechanics of breaking waves and observed that some aspects of breaking process were very similar in both deep and shallow waters. Wang et al. (1982) measured the drift velocity at the wave breaking point. Easson and Greated (1984) determined the velocities under breaking wave crest using laser doppler anemometer (LDV).
