Standing-up Mechanism of Hydroplane Tsunami Barrier by using PIV Analysis

The Hydroplane Tsunami Barrier does not need electric power and human operation, and judgment as countermeasure against tsunami. It assumes that this breakwater is installed in a bottom of entrance to a port, a river mouth and so on. This barrier is actuated and stood up only by a hydraulic power of tsunami. When a tsunami goes down, it returns to an original position. It is operated also by a drawback of a tsunami. A getting caught of debris and sediment, ground deformation are mostly not influence for its action. In this research, the Particle Image Velocimetry (PIV) was conducted for fluid analysis neighboring barrier body. To reproduce the one-way flow which simulated a tsunami, experiments are conducted by the steady flow in the circulating open channel. It is concluded that the lift force by vortex in theory of wing sections such as airplane is the main dynamic force of standing-up mechanism also in this barrier. Results clearly show that a strong lift force is generated by the turbulence structure. Moreover, when the standing-up angle became 15 degrees or more, the backflow region occurred clearly in the upstream side of the barrier body. This phenomenon generated a strong drag force for standing-up of the barrier body. These lift and drag force for standing-up mechanism were revealed by this PIV analysis.