Case Study:
Advanced radiator for hybrid electric aircraft


As the aviation industry explores evermore innovative ways in which it can become more sustainable, a leading figure in this campaign is a company called Ampaire. Ampaire is developing (and indeed, flying!) hybrid-electric aircraft that will pave the way for an all-electric future for the entire aviation sector. Ampaire is flying two copies of what is currently the world’s largest plug-in hybrid aircraft, and also in the process of scaling its propulsion technology to a much larger model. Active aircraft test programmes in California, Hawaii, and Scotland accompanied with fast charging infrastructure installation are paving the way for introduction of sustainable aircraft on commercial routes. 

Electric aircraft are flying today, however most of them are small converted training aircraft. But as electric aircraft move up in size categories, drag and weight reduction of components such as the heat exchangers for the thermal management system offer increasing performance benefits, which are vital in the development of a truly viable alternative to traditional flight. To this end, Ampaire have engaged the Applied Technologies team to explore the possibility of applying its expertise in adapting ultra-lightweight thermal management technologies to develop a radiator that can allow ready integration into low drag annular inlets which will contribute to a much more aerodynamic aircraft.

Advanced radiator for hybrid electric aircraft

About Ampaire

Ampaire is an exciting new electric aircraft start-up based in Los Angeles (with additional presence in the UK and Asia), with the aim to revolutionise aviation with efficient, quiet, and sustainable electric power. It currently operates multiple modified Cessna Skymasters which have been adapted to use an electric drivetrain. They are also working on converting a Twin Otter to plug-in hybrid-electric, as well as engaging in early modelling and hardware testing for its TailWind clean sheet design. Ampaire is leading in employing electric propulsion units leveraging advanced silicon carbide inverter technology and direct-drive permanent magnet motors, however thermal management remains limited by traditional radiator technology.   

The project

As part of Ampaire’s technology development they were keen to explore design space that Reaction Engines’ heat exchangers would open up. The annular form factor of Reaction Engines’ radiators allows for a low drag installation and optimised inlet geometry. And even though the high efficiency electric motors, inverters, and batteries generate less waste heat than a combustion engine, it is typically low grade waste heat with a small temperature difference to the ambient air stream. This in turn drives the need for heat exchangers with a higher surface area – usually meaning a larger and heavier heat exchanger and associated inlet. The project would essentially require a solution that does not currently exist and would need to be developed by a partner with experience of adapting and scaling thermal management technology. Developing an effective solution would improve aircraft level aerodynamics and energy efficiency, while providing more effective component cooling.

Advanced radiator for hybrid electric aircraft

Creating value

Applied Technologies have extensive experience of adapting the ground-breaking heat exchanger technology developed under the company’s SABRE programme for a range of industries and applications. With experience gained on similar projects in the motorsport sector, the team is currently developing an ultra-lightweight radiator with a very low pressure drop on the air side to allow the use of ram air in flight. This radiator will offer lower cooling system drag and higher cooling performance as well as offering mass and size reductions. 

Contact us on to find out how we can help you unlock the potential in your business.

< Back to Case Studies