Thermal management requirements for aerospace applications continue to grow while weight and volume allotments remain constant or shrink. Compact, high performance and lightweight heat transfer equipment is needed to meet these high heat flux removal requirements. Several innovative heat transfer enhancement techniques are being considered for development of thermal management components that will meet these challenging demands. Honeywell, under an AFRL funded program, is developing two new heat exchanger technologies; microchannel and advanced heat transfer surfaces to improve thermal management systems for a fuel-to-air heat exchanger.
Heat transfer systems in military aircraft are increasingly using fuel as a heat sink. Heat transport loops containing several fuel-to-liquid heat exchangers are used to cool electronics, engine oil, hydraulic oil, and elements of the thermal management system. Microchannel heat exchangers are especially suitable for these and other high heat flux removal applications due to their good thermal performance and extremely compact size. Traditionally, they have been used for thermal management of microelectronic devices. Recently, Honeywell conducted heat exchanger design trade studies, which highlights potential benefits of microchannels. The results from this study suggest that for liquid-air heat exchange applications, microchannel based metallic heat exchangers can offer potential 20-30% volume and/or weight reduction over state-of-the-art compact plate-fin design.
In the present study, use of microchannel and advanced heat transfer surfaces for a fuel-to-air compact heat exchanger for a fighter aircraft application is explored. Preliminary results from heat exchanger performance tradeoff and testing of prototype /subscale microchannels heat exchangers are reported. Finally, future development needs are summarized for their successful insertion for full-scale production.