Computation of Bay Currents and Its Possibility of Flow Control : A Two-Dimensional Model of Osaka Bay

Abstract

A tidal current in Osaka Bay is studied by using the finite-volume solutions of the two-dimensional time-dependent Navier-Stokes equations. The discretization technique with the geometric conservation properties in generalized curvilinear coordinate systems is developed based on Vinokur's idea. The primitive variable formulation uses the volume fluxes across the faces of each computational cell and the pressure defined at the center of cell as dependent variables. The simultaneous iterative procedure is applied for time advancement of the primitive variables to satisfy the discretized mass-conservation equation. The computational results show that a tidal current flows through the west part of Osaka Bay, but that it does not almost affect the current along the east coast of the Bay. The pairs of circulating flows with opposite rotation are found in the tidal residual current near both Akasi and Kitan Straits. Another numerical experiment is carried out to investigate the possibility of current control. An example is presented in which a small artificial island causes a large-scale circulating current in the center of the Bay, the effect of which reaches the east coast of the Bay.