Electrified Aircraft Propulsion (EAP) is a growing NASA technology effort that could enable new configurations of aircraft. With the potential to transform the transportation and services markets, vehicle classes of interest include single-aisle, thin/short haul, and urban air mobility. These vehicle concepts rely on hybrid electric systems to provide propulsive power through the use of a turbo-generator combined with electrical energy storage. For turbo-generators/range-extenders utilized in regional EAP concepts, small lightweight turboshaft engines are an excellent choice due to their maturity and availability. However, at small power scales, gas turbines are less efficient. This can be addressed using a recuperator to inject waste heat from the turbine back into the thermodynamic cycle upstream of the combustor. Micro Cooling Concepts (MC2) has developed technologies for fabricating extremely compact metallic heat exchangers with high heat transfer while reducing size and weight by 2-3X, using the printed circuit heat exchanger (PCHX) approach. Using additive manufacturing to create heat exchangers with finer scale and higher aspect ratio features can magnify the advantages of MC2’s existing technology, resulting in recuperators with minimal weight, volume, and pressure losses. Analysis shows that the 3D-printed hybrid laminate recuperators provide reductions in volumes and weight of 4.4X and 7.7X, respectively, compared to conventional recuperators. These weight reductions translate directly into shorter fuel payback times and opportunities to increase payload or range. The program will consist of recuperator design studies, fabrication studies, fabrication and testing of sub-scale test articles, and full-scale prototype fabrication and testing at engine relevant conditions. This effort supports the NASA goal of reducing the mass and increasing the efficiency of heat acquisition and rejection components and advancing technologies for more electric aircraft.
Technology applicable to any NASA program where heat exchangers are required and weight has a significant impact on system performance. Examples include:
Lightweight compact heat exchangers have uses across wide range of applications. Impact cannot be overstated as applicability to military and commercial sectors is vast: