Prediction of electronic component temperatures at high altitude using low altitude measurements

Analytical predictions of developing-flow, forced-air-cooled electronic component temperatures at high altitudes using near-sea-level temperature measurements are compared with the results of experiments performed at 198 m (650 ft) and 1646 m (5400 ft) above sea level. The correlation derived does not agree with correlations in the literature for fully developed laminar or turbulent two-dimensional flow over a constant-temperature flat plate, but predictions fall within +or-3.8% and -1.1% of measured temperatures, respectively. Altitude correction factors for ambient air preheat and module thermal resistances measured at 198 m are determined for 915 m (3000 ft), 1646 m (5400 ft), and 2135 m (7000 ft). An example of temperature prediction for 2135 m based on measurements made at 198 m is presented.<>