INVESTIGATION OF A HEAT-PIPE ARRAY FOR CONVECTIVE COOLING

A combined experimental and analytical investigation was conducted to evaluate a heat pipe convective cooling device consisting of sixteen s mall copper/water heat pipes mounted vertically in a 4 x 4 array which was 25.4 mm square. The analytical portion of the investigation focus ed on determination of the maximum heat transport capacity and the res istance of the individual heat pipes. The resistance of each heat pipe was found to be 2.51 K/Watt, or more than 3 times smaller than the re sistance produced by a solid copper rod with the same dimensions. The maximum predicted heat rejection for the module was over 50 Watts, or a power density in excess of 7.75 Watts/cm(2). In the experimental por tion of the investigation, two different modules were tested. The firs t module utilized ten circular aluminum fins mounted on the condenser end of each heat pipe to enhance heat rejection, while the second cont ained only the sixteen copper/water heat pipes. The effects of flow ve locity, input power, and base plate temperature on the overall thermal resistance and the heat rejection capacity were determined as well as the pressure drop resulting from each module. The finned heat pipe ar ray was found to have a lower overall thermal resistance and thus, a h igher heat rejection capacity, bur also resulted in a significantly la rger pressure drop than the array without fins. The results of the hea t pipe array experiments were also compared with experimental and empi rical results obtained from flow over a flat plate 25.4 mm square.