FADEC Thermal Management

The Full Authority Digital Engine Control (FADEC) controls engine operation. The FADEC case must be maintained below 63°C, while the environment can be as hot as 170°C. The current design uses fuel to cool the FADEC, however, this often limits the allowable ground or flight idle time before the fuel is too hot to cool the FADEC. This SBIR Phase I project will develop a thermal management system for the FADEC that includes four components: 1. Active cooling to reject the FADEC waste heat to higher temperature heat sinks, 2. Heat pipes and other devices to reduce the temperature gradients inside the FADEC box, 3. Insulation to reduce the heat in-leak from the environment into the box, and 4. Thermal storage, to store heat at times when it cannot be rejected. The use of heat pipes and insulation will increase the heat rejection temperature for the FADEC from the current 63°C (145°F) to 87°C (189°F). This can be further increased with active cooling. The benefits include an increase in the allowable fuel temperature, increasing idle time. The goal of the Phase II program will be to design, fabricate, and test a full scale thermal management system for cooling the FADEC. BENEFIT: The thermal management system has direct application to cooling the FADEC on current and future fighter aircraft platforms. Heat will be rejected to either a remote sink, or to the fuel at a significantly higher temperature than currently. Even without active cooling, a redesign of the FADEC box internal heat spreading and insulation increases the heat rejection temperature from the current 63°C (145°F) to 87°C (189°F). For some near-term applications, this might be sufficient. Future FADEC boxes will have higher power, likely requiring active cooling. ACT plans to work with Hamilton Sundstrand Aerospace during the Phase I, II, and III programs to rapidly transition this cooling system from a concept to a product. In addition to the FADEC, there are a number of additional electronics boxes with maximum allowable temperatures only a few degrees above the FADEC. The cooling system developed here can also be applied to these electronics boxes.