NUMERICAL ANALYSIS OF HEAT TRANSFER IN A LAMINAR, SUBMERGED, SLOT JET IMPINGING ON AN OSCILLATING WALL

Numerical simulation results of flow and heat transfer resulting from a confined, submerged liquid jet impinging on a planar oscillating surface are presented here. Laminar jets are employed in places where space and pumping capacity constraints exist (for example, in electronics cooling). However, in a laminar single jet, the cooled region due to the jet is small and is concentrated in the stagnation zone. One way to potentially enhance the heat transfer in a laminar jet impingement arrangement is by oscillating the heated impingement surface. This work extends the previous fluid dynamics analysis (by the same author) by a description and quantification heat transfer in such an arrangement. The problem is studied with respect to two parameters governing jet impingement :Jet Reynolds Number, distance from the jet inlet to the impinging wall (z/d ratios) and a parameter characterizing oscillation : the oscillatory peak Reynolds Number. OpenFOAM (foam-extend 3.2), an open-source CFD code based on the finite volume method is used to solve the problem. Quantification of discretization uncertainty is done by employing the Grid Convergence Index Method (GCI). The transport of the vortex structures formed due to the confined arrangement of the jets and due to the oscillation of the target wall has a strong influence on the temperature distribution on the target surface. The enhancement in heat transfer is estimated as a ratio of the Nusselt Numbers cases with oscillation to corresponding cases without oscillation. It is shown that the heat transfer enhancement is a strong function of the jet and the oscillatory parameters considered.