Advancing technology for aircraft turbine engines, as defined in the IHPTET initiative, will place increasingly severe thermal and structural demands on the components of the engine hot section. Materials technology is currently being developed with the goal of satisfying the demands of IHPTET Phase III and the future concepts engine. Although these materials will reduce the requirements for thermal management, some of the hot section components will still require cooling to lower temperatures than the available air streams, thus requiring that some of the engine cooling air be cooled to a lower temperature prior to use. The need for such "cooled cooling air" (CCA) defines a new thermal management requirement for future engine systems. Evaluation of resources to provide the required cooled cooling air indicate that the engine fuel is the most promising candidate to provide the necessary heat sink. To provide the necessary CCA using fuel as the primary coolant will require the use of fuel-air heat exchangers with enhanced capabilities, as compared to current conventional technology. Heat exchangers for this application must be capable of operating at high temperatures, with large temperature differences between the two streams, and must be designed to provide a very high level of system integrity, to avoid the safety hazards associated with leakage in fuel-air components.
Benefits: The development of this technology will enable future and current aircraft systems to increase the heat loads generated by avionics, actuators, hydraulics, etc. by providing cooled cooling air using fuel as the primary heat sink. The innovative core design can be used in numerous commercial applications where uniform heating (or cooling) of a fluid is required such as processing plants.
