Numerical Investigation of Thermal Transport in Foam Filled Heat Exchangers Employing Circular and Non-Cicrular Jet Impingement Cross Sections

Development of advanced electronic devices and microprocessors has resulted in high heat flux and temperature values in these devices. In order to keep the temperature of electronic devices at a safe temperature, different electronic cooling techniques have been introduced. It is shown that jet impingement can provide a high efficiency cooling for a variety of applications including electronics cooling. On the other hand, employment of conductive foam material improves heat transfer process and temperature control. In this study, uniform and non-uniform metal foam filled heat exchangers are investigated numerically. The heat exchanger employs jet impingement, indirect cooling, and highly conductive metal foam for heat transfer augmentation. The heat exchanger has a forced flow arrangement entering through a vertical inlet channel, passes through the foam substrate inserted inside a confined channel and leaves through two similar lateral exit channels. The base of the heat exchanger is attached to the surface of the device to be cooled and so the base is subjected to a uniform high heat flux value. For numerical modeling, local thermal non-equilibrium model in porous media is employed. In this model, volume averaging are performed over each of the fluid and solid phases in porous media which results in two energy equations, one for solid phase and one for fluid phase. The results are compared with data in literature for verification. The foam properties of two copper and aluminum metal foams are measured and used for simulations. The effect of jet impingement cross section is investigated by studying a rectangular, a square, and three different circular cross sections.