화학공학소재연구정보센터
International Journal of Heat and Mass Transfer, Vol.54, No.25-26, 5444-5458, 2011
Heat transport from a bluff body near a moving wall at Re=100
Numerical simulations are performed for the flow and heat transfer from a stationary 2D square cylinder placed near a moving wall at Reynolds number 100 and cylinder-to-wall gap ratios in the range 0.1 <= G/D <= 4. The governing equations are solved using a finite volume method. Flow and thermal field resemble that of isolated case when the cylinder is far away from the moving wall. When G/D < 1, the twin vortex shedding pattern is transformed into single row of negative vortices and eventually the flow becomes steady when G/D < 0.3. Lift ((C) over bar (L)) and drag coefficient ((C) over bar (D)) of the cylinder are higher compared to that of an isolated cylinder. Strouhal number (St) of the cylinder increases with decrease in gap ratio from 4 to 1. With a further decrease in gap ratio. St reduces drastically before vanishing at G/D = 0.3 as a consequence of vortex shedding suppression. In general, the heat transfer rates are higher than the case of an isolated cylinder. The mean Nusselt number (Nu(M)) increases with decrement in gap ratio. However, the trend is not the same. Nu(M) increases gradually when G/D is varied from 4 to 0.5, while it suddenly decreases with decrement in G/D from 0.5 to 0.3 and again rises sharply for G/D <= 0.2. Results indicate that an enhancement of 27.45% in mean Nusselt number can be achieved, compared to the isolated case, by placing the cylinder at G/D = 0.1. (C) 2011 Elsevier Ltd. All rights reserved.