Influence of incident wave angle on Mach-stem breaking

摘要

When obliquely incident waves with a small incident angle reflect from a vertical wall, a wave propagating along the wall (Mach-stem) can be generated. Such a reflection pattern is called as Mach-reflection. Many researchers have investigated the characteristics of Mach-stem waves experimentally and numerically. To evaluate wave overtopping and the stability of wave dissipating blocks, the influence of Mach-stem waves is significant. There is possibility that Mach-stem neglected at the conventional design is relevant to the damage of coastal structure. The stem waves formation has much influence on wave breaking along the structure. In the regular and irregular wave fields, the stem waves break more easily than the obliquely standing waves without the Mach-stem effect, for the same incident wave height and period (Memita et al., 2000). To predict the breaking of stem wave is important. There has been no literature dealing with the breaking height of Mach-stem waves. In this paper, an experiment is carried out to propose the method to predict the wave breaking height of Mach-stem. The development of Mach-stem along the wall with dissipating armor blocks is also examined.