Author(s): Shin-Jye Liang
Linked Author(s):
Keywords: Shallow-water equations; Bathymetry; Vortex streets; Least-squaresfinite-element method; Θ-method
Abstract: The effect of water depth on the characteristics of vortex streets is numerically studied. The numerical model is based on the non-conservative, two-dimensional depth-averaged shallow-water equations with the least-squares finite-element formulation in space and θ-method in time integration. Flow past a circular cylinder with the same boundary and initial conditions, in two different bathymetries, the constant slope bed and irregular bed, is investigated. Water surface around the cylinder and the dynamics of the vortex streets are examined. It is found that pairs of symmetric, alternatively cyclonic-anticyclonic vortices are found in the symmetric bathymetry setting, and highly asymmetric, alternating vortices with opposite rotations in the non-symmetric bathymetry setting. The bathymetry has a direct effect on the formation, strength, and characteristics of the vortex shedding, and consequently on the water surface around the cylinder and flow field upstream.
Year: 2009