抄録
The shallow water equations generate short-wave spurious oscillations if they are solved with the standard Galerkin finite element approach. In this article, a mixed finite element method with the quasi bubble-function element is applied to the equations to solve tidal currents. Numerical solutions of the quasi bubble-function scheme are investigated in comparison with analytical solutions and numerical solutions of the selective lumping method. The results indicate that the quasi bubble-function scheme is stable in the tested subcritical flows and yields accurate solutions with very low numerical dumping. The results of tidal current computations in Tokyo Bay show that the quasi-bubble mixed finite element method reproduces very detailed residual currents near coasts, which is important to transportation analyses, thanks to its low numerical damping property.
