{"title":"Vortex-Shedding Suppression in Mixed Convective Flow past a Heated Square Cylinder","authors":"A. Rashid, N. Hasan","country":null,"institution":"","volume":54,"journal":"International Journal of Mechanical and Mechatronics Engineering","pagesStart":953,"pagesEnd":962,"ISSN":"1307-6892","URL":"https:\/\/publications.waset.org\/pdf\/7771","abstract":"The present study investigates numerically the\r\nphenomenon of vortex-shedding and its suppression in twodimensional\r\nmixed convective flow past a square cylinder under the\r\njoint influence of buoyancy and free-stream orientation with respect\r\nto gravity. The numerical experiments have been conducted at a\r\nfixed Reynolds number (Re) of 100 and Prandtl number (Pr) of 0.71,\r\nwhile Richardson number (Ri) is varied from 0 to 1.6 and freestream\r\norientation, \u03b1, is kept in the range 0o\u2264 \u03b1 \u2264 90o, with 0o\r\ncorresponding to an upward flow and 90o representing a cross-flow\r\nscenario, respectively. The continuity, momentum and energy\r\nequations, subject to Boussinesq approximation, are discretized using\r\na finite difference method and are solved by a semi-explicit pressure\r\ncorrection scheme. The critical Richardson number, leading to the\r\nsuppression of the vortex-shedding (Ric), is estimated by using\r\nStuart-Landau theory at various free-stream orientations and the\r\nneutral curve is obtained in the Ri-\u03b1 plane. The neutral curve\r\nexhibits an interesting non-monotonic behavior with Ric first\r\nincreasing with increasing values of \u03b1 upto 45o and then decreasing\r\ntill 70o. Beyond 70o, the neutral curve again exhibits a sharp\r\nincreasing asymptotic trend with Ric approaching very large values\r\nas \u03b1 approaches 90o. The suppression of vortex shedding is not\r\nobserved at \u03b1 = 90o (cross-flow). In the unsteady flow regime, the\r\nStrouhal number (St) increases with the increase in Richardson\r\nnumber.","references":null,"publisher":"World Academy of Science, Engineering and Technology","index":"Open Science Index 54, 2011"}