Experimental evaluation of air cooling electronics at high altitudes

摘要

The effect of altitude on electronic cooling is evaluated experimentally. Material properties of air vary as a function of altitude due to changes in atmospheric pressure and temperature. These changes have a negative impact on the heat transfer effectiveness and result in higher component temperature when compared to sea level conditions. Experiments are carried out in a hypobaric chamber using electronic printed circuit boards populated with heated rectangular blocks placed in a small wind tunnel. The altitude is varied between 0 and 5000 m above sea level and the air speed is varied between 1 and 5 m/s. The results show the local adiabatic heat transfer coefficient and thermal wake function diminish with altitude. This information is useful for design and analysis of electronic equipment for operation over a range of altitudes and air speeds typically econtered in forced air convection cooling applications.