Better thermal management for cooler aircraft electronics

Over time, there has been a move within industry to run all aircraft power systems on electricity, thus leading to considerable cost, weight and environmental savings. However, this electric aircraft concept imposes new challenges in the field of thermal management. Electronic designers are required to meet the strictest technical specifications with regard to withdrawing payload dissipation and optimising the weight and compactness of new equipment.

Work in the project AEROL-HP (Development, construction, integration, and progress toward to two-phase device monitoring and qualification on aircrafts) revolved around developing on-board two-phase cooling devices to make sure that they meet specified aeronautical requirements. These include high acceleration loads and long vibration stress cycles, as well as reduced equipment weight and passive designs.

The developed technology is based on the use of a flexible thermal device composed of five mini-loop heat pipes filled with acetone. The pipes carry heat from equipment located inside aircraft to the aircraft structure. The condenser lines of the mini-loop heat pipes are assembled on saddles that are connected to the plane structure. Researchers proposed this cooling solution because it optimises thermal, hydraulic and mechanical performances, in addition to mass, flexibility and cost. They also presented monitoring solutions to check against failure and downtime of the cooling device.

The innovative thermal device can be applied for cooling battery control units, electrical ice protection units, electrical power distribution units and in-flight entertainment systems. Other possible uses are cooling of electromechanical actuators for horizontal tail plane trim and for flight control surfaces.

AEROL-HP objectives were aligned with the Clean Sky initiative. The project's highly efficient passive thermal control device increases equipment reliability and contributes to reduced fuel consumption thanks to its light weight. By ensuring that it is in accordance with specified requirements, it should be widely used in all-electric aircraft.