Experimental Investigation of Thermal and Hydraulic Performance of V-Shape Corrugated Carbon Foam

Abstract

In air-cooled heat exchangers, air-side thermal resistance is usually the largest compared to conduction and liquid-side thermal resistances. Thus, reducing the air-side thermal resistance can greatly improve overall cooling performance. The performance of an air-cooled heat exchanger is usually characterized by the rate of heat which can be transferred and the pumping power required to convect the heat away. This paper presents a method of utilizing V-shape corrugated carbon foam to improve thermal performance. The air-side heat transfer coefficient and the pressure drop across the foam have been investigated using different V-shape foam geometrical configurations obtained by varying its length and height. Based on design considerations and availability, the foam length has been chosen to be 25.4, 38.1, and 52.1 mm, while its height is 4.4, 6.8, and 11.7 mm, resulting in nine different test pieces of foam with different heights and lengths. A total number of 81 experiments were carried out with different air face velocities (0.7-9m/s) and heat fluxes at the heater surface (0.5-2W/cm2). The pressure drop across the V-shape corrugated carbon foam as well as inlet air, exit air, foam, and ambient temperatures were measured. Of the nine V-shape configurations, the foam with the shortest length and tallest height gives the best performance. The present results are also compared with the results of prior work using different carbon foam geometries. It is shown that V-shape corrugated carbon foam provides better heat transfer coefficient and the overall performance.