Gas turbine engines may include a recuperator, which is a heat exchanger using hot exhaust gas from the engine to heat the compressed air exiting the compressor prior to circulation of the compressed air to the combustion chamber. Preheating the compressed air usually improves fuel efficiency of the engine. In addition, the recuperator reduces the heat of exhaust gas, which helps minimize the infrared signature of the aircraft.
However, the high temperature differential within the recuperator typically induces thermal stresses which can significantly reduce its life. Seal failures may occur between the recuperator and the adjacent components, and such may affect the reliability of the engine. Some prior art recuperator structures are also relatively heavy and/or costly to manufacture, and as such generally unsuitable for aircraft use.
Accordingly, improvements are desirable.