ACTIVE COOLING HEAT TRANSFER COEFFICIENT ENHANCEMENTS IN POROUS COMPACT HEAT EXCHANGER

Abstract

Due to the poor thermal properties of the air and the resistance of the boundary layer, enhancing the heat transfer coefficient HTC is a challenging problem. In this study, the hydro-thermal characteristics of V-shape copper porous media attached to a vertical heat source were studied by using the active cooling forced convection technique. The performance of hydraulic is expressed by pressure drop through the porous insert material while the thermal performance is expressed by the overall HTC and Nusselt number. To conduct this research the finite element method (FEM) is used by employing the COMSOL software. The V-shape geometry was chosen as the porous thickness is 2 mm and the porous height is 4 mm. The V-shape angle was changed from 14 to 180, and the airflow velocity was varied from 0.7 m/s to 3 m/s. The results show that angle 14 gives the minimum pressure drop so minimum pumping power. For laminar airflow changing air velocity from 0.7 to 3 m/s led to a change in the pressure drop from 44 to 530 Pa and the Nusselt number ranges from 186-1592. V-shape with an angle of 14 degrees gives the best hydraulic performance for the selected geometry and The best performance criteria is at porosity 25% and Reynolds number 4617. The best enhancement of the heat transfer coefficient from this geometry is 8 times more than that from the bare model. Correlations for Nusselt number and performance criteria were concluded. Special Issue of AEIC 2024 (Mechanical & Chemical and Material Engineering Session)