Cross-buoyancy mixed convection from a heated cylinder placed asymmetrically in a channel

摘要

Mixed convection heat transfer from a heated circular cylinder asymmetrically placed in a horizontal channel was studied for incompressible Newtonian fluid. A systematic investigation using two-dimensional numerical simulation (Ansys Fluent) was performed for the following control parameters: Reynolds number Re = 50, 100, 150, Richardson number Ri = 0, 1, 2, blockage ratio beta = 0.2, 0.3, 0.4, gap ratio gamma = 0.25, 0.5, 1 and Prandtl number of air PT = 0.7. Upon changing these parameters, steady and time periodic regimes were identified. The strongest influence on heat transfer (average Nusselt number) was identified when changing the Reynolds number (a 94% increase between the minimum and maximum Re investigated, with other parameters held constant), followed by Richardson number (+18%) and blockage ratio (+ 16%); the effect of asymmetric placement (gamma) was almost negligible (+ 1%). The time-mean of the drag coefficient was most influenced by blockage ratio (a 150% increase), followed by Richardson number (+ 91%), gap ratio (+ 19%), and Re (+ 10%).