Numerical Study of Fluid Flow and Heat Transfer in a Backward Facing Step with Three Adiabatic Circular Cylinder

In this study, the analysis of the heat transfer enhancement and laminar fluid flow characteristics of three non– rotating adiabatic cylinders in the backward facing step geometry is numerically performed. The effects of Reynolds number, heat fluxes, and longitudinal distance between two consecutive cylinders on the heat transfer characteristics are studied for backward facing step flow. Five Reynolds number are studies (Re = 50, 100, 150, 200, 250) and three heat fluxes on the lower wall of the channel are (q” = 250, 500, 750 W/m 2 ), the longitudinal distance are (2H, 3H, 4H), where (H = 10 mm) which represent the cylinder diameter. The governing equations are discretized and solved using the finite volume method over a control volume by ANSYS Fluent software. The results show the heat transfer is increased in the channel. The reattachment distance decreased when using cylinders. The heat transfer enhancement increases from (6 %) to (13 %) if the Reynolds number change from (50) to (250) when heat flux increases (67 %). A good agreement is found when comparing the present results with literature.

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