Performance characterization of high-power electronic equipment onboard anaircraft

A skin cooling system has been developed to reject heat from high-power ele ctronic equipment onboard an aircraft. In this system, the heat is rejected through the aircraft skin by use of internal skin ducts with enhanced surf aces. Hear transfer through the skin and the air flow in the system have be en modeled and experimentally verified in the laboratory environment. In ad dition, the Effect of the ducting system on the performance of the electron ic equipment has been characterized. This article describes a series of tests that were performed to verify the modeling assumptions for heat dissipation from and airflow through the equi pment. The tests were performed using the actual electronic equipment in a representative cabin configuration and at cabin conditions. Results show that the equipment operates at a higher temperature at cabin c onditions than at room conditions. This is due to the constant volumetric f low throughput of the equipment fan at higher altitudes but lower mass flow rate (i.e., lower density) at cabin conditions. Furthermore, the equipment back-pressure produced by the cooling system adds to the heating of the eq uipment. The compatibility of the equipment fan is also critical in the sta cking arrangement of the equipment.