Reciprocating turbulent flow heat transfer enhancement within a porous medium embedded in a circular tube

Heat transfer enhancement of turbulent reciprocation flow was investigated numerically in a tube filled with porous media subjected to a constant wall temperature using the Low and High Reynolds turbulent models. The flow is simulated using the Darcy-Brinkman-Forchheimer and the local thermal equilibrium models. The finite volume approach is used to discretize the transport equations for flow and heat transfer in an oscillatory flow through a porous media. The effect of different parameters such as kinetic Reynolds number (Re-omega= 1600-10,000), Darcy number (Da = 10(-6)-10(-1)), dimensionless amplitude oscillation of fluid (A(0) = 12-40) and Forchheimer coefficient (F= 0-2) on the heat transfer and friction factor were studied. According to the obtained results, two correlation equations were introduced for maximum friction factor (f(max)) and space-cycle averaged Nusselt number (Nu(s_ave)) in terms of Da, A(0), Re-omega and F. Although, the reduction of Da Number enhances the heat transfer but it increases the pressure loss dramatically. It was also found that Nu(s-ave) and f(max) are independent of inertia coefficient for Re(max)Da(0.5) values lower than 1. The impact of inlet and outlet temperature oscillations on the heat transfer was not significant. (C) 2016 Elsevier Ltd. All rights reserved.