An outdoor electronic equipment is under consideration. In order to attain the desired system performance and reliability, the junction temperature of all electronic components and the base plate temperature of the power supply under the worst environmental conditions must be kept below 105°C and 85°C, respectively.
A system level transient analysis is performed to determine the temperatures of the internal air and the power supplies which are mounted to the internal structures of the system. The transient is caused by the daily cycle of ambient temperature and solar flux. The internal air temperature and the base plate temperature of the power supply are computed for a 24-hour period. The above thermal design limits are met with the computed internal air temperatures and flow rates.