Numerical study on thermal performance of lotus type copper porous heat sink

Lotus type porous metal is a novel heat sink used in various applications. It is fabricated through unidirectional solidification of molten metal in a pressurized gas environment. The uni-directional pores are developed as a result of deposition of supersaturated gas in liquid metal during solidification. The aim of this study is to determine the effect of porosity on the thermal performance of a lotus type copper porous metal through numerical analysis. The porosity of lotus type heat sink can be change by varying the pore diameter and number of pores in the porous metal. In this work four different porosity values were considered for analysis with four different pore diameters. The heat transfer coefficient (h) of all the models were compared and arrived at a conclusion on how heat transfer coefficient varies on changing the porosity and pore diameter of the heat sink. ANSYS 18 version was used for the simulation and appropriate assumptions were implemented to reduce the complexity of the conjugate heat transfer problem. The results show an increase in convective heat transfer increase in porosity of the heat sink. Also with increase in pore diameter the convective heat transfer rate also increases, attains a peak value and then decreases. Application: The lotus type porous metal is widely used for cooling microprocessor chips used in CPU and other embedded systems, where the heat generated would be easily dissipated through the micro channels present in the lotus type porous metal thus securing the system from damage.