Vortex Shedding for Flow Over a Square Cylinder Close to a Moving Ground
Flow past a cylinder of square cross-section placed near a plane sliding wall has been investigated. This work aims to address questions regarding the characteristics of the vortex shedding regime and its modifications with the variation of wall to cylinder gap height and Reynolds number. The governing unsteady Navier-Stokes equations are discretised through the finite volume method. A SIMPLER algorithm has been used to compute the discretised equations iteratively. A uniform velocity profile equal in speed of the wall speed impinges on the cylinder. An alternate vortex shedding is found in the cylinder near wake for Reynolds number (based on cylinder height) greater than 80. The boundary layer along the moving wall separates and the secondary vortex forms in the region downstream of the cylinder. Unlike the stationary ground case where the vortex shedding suppression occurs beyond a critical value of gap length, here the vortex shedding takes place even at low gap length ratio 0.1. We found that the cylinder experiences a upward force at higher values of Reynolds number. The gap flow is strong and the velocity profiles overshoots its free stream value within this region.
KeywordsReynolds Number Shear Layer Strouhal Number Bluff Body Stationary Wall
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