Hazards evaluation of drowning in tsunami floods through human-fluid coupled numerical analyses

Abstract

We developed a new numerical model toward simulation of human-body movement in tsunamis. A combination of a multiphase fluid solution: CIP-CUP method and a method to represent a human body: link segment model enabled human-fluid coupled analyses. We evaluated the new model by comparing results with some flume experiments. Here, an isolated wave traveled in a large flume and generated a whirlpool behind blocks laid in the downstream sector. At the same time, a manikin was laid on the blocks and caught in the whirlpool. Our new model represented the body’s movement precisely there. Next, we applied some additional buoyancy to the human body model toward evaluation of performance of life jackets. Consequently, there was a threshold of life-jacket buoyancy which is required to keep a human body floating. Besides, we showed that computation of unsteady flow is necessary to evaluate performance of life jackets in tsunamis. Especially behind some structures like the experiment, the amount of buoyancy required to the life jackets can be evaluated by comparing it with center-seeking pressure of the whirlpool mainly applied to the legs.