Low-Observable Heat Rejection from Aircraft

ABSTRACT: An innovative approach for removing low-quality (<40C) waste heat generated by directed energy and other electrically based technologies from aircraft is proposed. The proposed innovation removes heat from air platforms in a manner that will allow the system to meet size, weight, and power constraints and not significantly impact survivability or aerodynamic performance. This is accomplished through use of a gas expansion process powered by the low pressure third stream flow of an advanced, three stream engine. By expanding the third stream flow, its temperature is reduced to a level that accommodates removal of low quality heat. This innovation provides a low pressure source for expanding the third stream air to maximize its ability to absorb heat. Performance losses are minimized by introducing the expanded air into the exhaust nozzle to generate thrust. Preliminary assessment indicates that steady-state heat removal in excess of 100kW is attainable with this system. Coordination with OEMs will ensure that the resulting system meets Power and Thermal Management System (PTMS) requirements for 5th and 6th generation fighters. BENEFIT: This SBIR effort (Phase I and II) will result in the development and implementation of a heat rejection system capable of removing large, low quality thermal loads applicable to fighter, bomber, and gunship platforms. Work being conducted for the JSF (F-35) in the JAETMIS and AETD programs is exploring use of advanced, variable three stream engines in later production blocks, providing an excellent opportunity for integrating this heat rejection system within future blocks of the JSF. The heat rejection system also provides a potential thermal management solution for other aircraft, such as Small, Unmanned Aircraft Systems (SUASs), and Unmanned Combat Air Vehicles (UCAVs). This provides an important contribution as an enabling technology for achieving the thermal management goals of the DoD.