HCE Kerosene Piston Engine Light Helicopter Demonstrator Results

In the frame of GRC4, part of Cleansky's Green Rotorcraft Integrated Technology Demonstrator (ITD), Airbus Helicopters has led the development of a flying demonstrator based on the H120 serial helicopter and fitted with a designed from scratch reciprocating engine running on kerosene and named HCE for High-Compression Engine. On this research project Airbus Helicopters teamed with TEOS Powertrain Engineering, France, and AustroEngine GmbH, Austria, regrouped in the Consortium HIPE 440. Engine bench tests started in March 2013. Ground tests were completed in March 2015. With a Maiden Flight on November 6th 2015, the flight test campaign is to last until the end of 2017. This paper explains the specifics of the High Compression Engine, which triggered the need to build the new engine from scratch. It more particularly presents the achievements of the research project in terms of engine mass-to-power ratio, power output, fuel consumption, torque oscillations, engine displacements, rotor speed control and cooling system, which achievements where revealed during flight tests carried with up to 32°C OAT (ISA+17°C).