Author(s): Mohammad Bagus Adityawan; Hitoshi Tanaka
Linked Author(s): Hitoshi Tanaka
Keywords: Simultaneous Coupling Method; Dam break; Boundary layer; Shallow water equation
Abstract: The bottom boundary layer plays an important role in the bed stress behavior under unsteady wave motion. The simultaneous coupling method (SCM) was proposed to accommodate the boundary layer approach in the shallow water equation (SWE). In this study, the application SCM is further explored for assessing the boundary layer beneath the wave generated by a dam break. The SCM improves the accuracy of the SWE model by replacing the conventional bed stress assessment with a direct estimation from the boundary layer using the k−ω model. In addition, SCM uses the First Order Center Scheme and Monotonic Upstream Scheme of Conservation Laws (FORCE MUSCL), extend the SWE range. The SCM provides a better agreement to the measured water level profile than the conventional SWE with Manning empirical approach due to a more accurate bed stress assessment. The SCM is able to reproduce the boundary layer development and the known behavior of bed stress under unsteady motion, which can not be explained by the conventional Manning approach.