Highly confined flow past a stationary square cylinder

Abstract

Present work explores a numerical study based on Finite-Element Method for fluid flow past a stationary square cylinder placed symmetrically in the channel with high Blockage, B = 0.9. Reynolds Number (Re) progressively varied from 5 to 150 in the laminar region. An attention has been paid to capture the exact point of laminar flow separation on the surface of the cylinder and the separation Re for high blockage flow. The steady to unsteady flow transition is observed at a Re (Rec) of 62. A very high drag coefficient, order of magnitude = 103 is reported for the computation. Inconsistency with unbounded flow solutions, the wake bubble for 90% blockage cylinder shows nonlinear variation with Re in the steady flow regime. In a very narrow regime near the beginning of unsteadiness, the flow is found to be quasi-periodic whereas, for all remaining Reynolds number values considered for the present study, periodic flow is observed.