Integrated Aircraft Thermal Management and Power Generation

Future military aircraft will demand lower cost and lower weight subsystems that are more reliable, and easier to maintain and support. To identify and develop subsystems integration technologies that could provide benefits such as these to current and future military aircraft, the Air Force Wright Laboratory (WL/FIVE) initiated the Subsystem Integration Technology (SUIT) program in 1991. McDonnell Douglas Aerospace (MDA) together with Pratt and Whitney (PWA), and AlliedSignal Aerospace Systems and Equipment (ASE) was one of three teams that participated in Phase I of the SUIT program. The MDA Team's goal was to conceptually formulate a SUIT approach which would provide significantly reduced weight and costs while increasing cooling and power generation capabilities. These goals were achieved with a new and innovative energy subsystem suite which integrates aircraft and engine subsystem power, cooling, pumping, and controls. The suite emphasizes the integration of power and cooling equipment rather than advances in component technologies, i.e. no hardware breakthroughs are required. A key feature of the suite is the Thermal and Energy Management Module (T/EMM) which integrates turbomachinery consisting of compressor, power turbine and cooling turbine with a generator, hydraulic pump, combustor, and controls. The T/EMM provides the power and cooling functions traditionally performed separately by an Auxiliary Power Unit (APU), an Airframe Mounted Accessory Drive (AMAD), and an Environmental Control System (ECS). The Team's SUIT approach to energy subsystem integration potentially reduces subsystem weight by 25 percent and subsystem support costs by a factor of 2, while increasing cooling and power generation capacity by a factor of 3 over current fighter aircraft subsystems. The energy integration of the thermal management and power generation is the subject of this paper. A description of the T/EMM, its performance characteristics, and its projected impact on an advanced fighter aircraft performance are provided along with future T/EMM development plans.