The high-altitude environment with a low atmospheric pressure and low air density would significantly affect the cooling performance, which can further affect the heat dissipation of driving system. This work studies the impacts of the high-altitude environment on cooling the driving system of high altitude aircrafts. A 3-D CFD model was developed. Based on simulations, the influences of the altitude, solar radiation and the heat load on the operating temperature of the driving system were analyzed. The cooling performances on the ground and at high altitudes were also compared. The results showed with the increase of altitude, the maximum temperature of driving system decreased firstly until 4km and then increased. And a large deviation (12oC) would occur if the solar radiation was not considered for high altitude aircrafts.
Keywords driving system, finned radiator, high altitude, solar radiation, cooling