High powered electronic equipment generates a considerable amount of heat - often in very confined enclosures. Furthermore, electronic equipment has narrow thermal operating conditions. This is why thermal control has always played an important role in the design of electronics which must be extremely reliable, such as on board aircraft.
Complicating the design of airborne electronics is the fact that the environment is harsh with ambient air temperatures ranging from -55 to 100 °C or more, and weight and volume constraints demand a compact design.
Natural convection alone is not sufficient to keep airborne electronics at reasonable temperature levels, therefore, designers have turned to forced convection. On board advanced aircraft, such
as fighters, an environment control system is used to supply cool air to the electronic equipment. This type of cooling creates problems due to pollutants (dust, sand, metals, liquid droplets) in the flow which can cause micro electronic shorts and/or abraid the electronic surface.
To solve the problem, engineers have turned to passing the cooling flow over fins. The only accurate way of predicting pressure drops and temperatures is to perform a CFD analysis. The simulation yields cooling performance and pressure drops for aid in fan selection. The CFD results can also be used as input to a detailed thermal analysis of the circuit board.
Through the use of CFD, advanced designs of airborne electronics are made possible.
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