COMPACT MODELLING OF FORCED CONVECTION IN PIN/PLATE-FIN HEAT SINKS SUBJECTED TO IMPINGING JET HEATING

摘要

Built upon the porous medium approach, a compact model is presented for forced convection in pin and plate fin heat sinks subjected to non-uniform heating. The modified Darcy's law and the two-equation model are adopted separately to describe fluid flow and heat transfer in the porous model. To take account of heat spreading in the plate-fins and its absence in the pin-fins, the concept of anisotropic effective thermal conductivity is employed in the energy equation for the solid phase. To validate the model, experiments are conducted for both pin- and plate-fin heat sinks and the measured local temperature distribution on the heat sink substrate is compared with that predicted. Experimental results reveal that, due to additional heat spreading in the plate-fins, the substrate temperature of the plate-fin heat sink has a more uniform distribution than that of the pin-fin heat sink. Obtained good agreement between model predictions and experimental measurements suggests that the present model is suitable for predicting the spreading effects in the connected solid phase of porous media (e.g., plate-fins) under non-uniform heating boundary conditions.