Control Strategy and Optimization of Available Heat Sinks within Aircraft Thermal Management Systems for Maximizing Mission Life Navy SBIR FY2010.3 Sol No.: Navy SBIR FY2010.3 Topic No.: N103-200 Topic Title: Control Strategy and Optimization of Available Heat Sinks within Aircraft Thermal Management Systems for Maximizing Mission Life Proposal No.: N103-200-0755 Firm: Mainstream Engineering Corporation 200 Yellow Place Pines Industrial Center Rockledge, Florida 32955 Contact: J. Cutbirth Phone: (321) 631-3550 Web Site: www.mainstream-engr.com Abstract: With the reduced emphasis on ram-air and the disadvantages of using engine fan-bypass air as heat sinks, onboard fuel has become increasingly popular to deposit waste heat. However, with advanced aircraft, such as the Joint Strike Fighter (JSF), replacing traditional hydraulic-, mechanical-, and pneumatic-powered systems with high-powered electrical systems, the waste heat load can exceed the thermal capacitance of fuel being transported from the tanks to the main-engine combustor during low-thrust operational. Thus the fuel is recirculated to the tanks, lowering the remaining thermal capacity. The goal of the SBIR effort is to demonstrate a user-friendly interface and control software that monitors the remaining heat capacity of the onboard fuel. Mainstream's approach will yield a software and hardware suite capable of not only monitoring the available thermal capacity of the fuel, but optimizing the utilization of on-board heat sinks (fuel and fan-bypass air for the JSF thermal management system). The Phase I effort will focus on the development of the control architecture and optimization strategy while demonstrating performance using operational mission profiles. The Phase II will focus on the user interface and demonstration of the integrated software and hardware with an experimental TMS representative of the JSF TMS. Benefits: Increasing the heat removal capacity for high-density variable heat loads, such as that found aboard avionic systems, remains a major technical challenge for NASA, military, and civilian applications. Typically, the TMS is coupled to numerous heat sinks or thermal energy storage (TES) systems. For example, aboard the JSF aircraft, two options are available for depositing the electronic/avionic waste heat: fan bypass air and fuel. Each has limitations: heat removal using fan bypass air increases fuel consumption limiting flight range and heat removal using fuel decreases the remaining thermal capacity of the fuel. Furthermore, solicitations exist to develop TES systems utilizing latent (paraffin melt) and bond-reaction (hydrogen/water absorption) heat storage. The usage of TES systems yields another layer of complexity for the TMS. As such, control algorithms and optimization strategies are required to allow these new TMS to reach their full potential. For the current SBIR, the Phase I effort is significant as it focuses on optimizing the operational range of the aircraft in terms of heat sink availability which can be compared to operational range remaining in terms of remaining fuel supply while providing constant feedback to the user (i.e. pilot). Return