Waste heat for rotorcraft power

The aerospace sector demands increasingly efficient engines to decrease fuel consumption and associated emissions. However, the latest rotorcraft engine technologies designed to meet the demand require more power than in the past.

Harvesting waste heat for electricity production can provide the additional power without hampering achievement of the original aim of sustainability. Scientists have now conducted a thorough analysis of the technical and economic potential and feasibility of waste heat recovery for rotorcraft within the scope of the EU-funded project 'Thermal energy recovery electrical systems' (RECYCLE).

Work began with identification of all sources of heat loss in rotorcraft systems that could be exploited for electricity production. Scientists then reviewed the most innovative technologies worldwide to recover those losses. Technical performance was not the only consideration. Researchers evaluated the risk of potential solutions, including electrical and magnetic interference issues, structural integrity and flight safety.

The most promising candidates underwent a thorough analysis, resulting in detailed heat and power balance flow diagrams. A conventional Rankine cycle was chosen. Development of a rotorcraft power system simulator enabled testing the high-level system behaviour.

RECYCLE's systematic study of thermal heat recovery systems for electrical power generation from waste heat will pave the way to more sustainable and green rotorcraft. Advanced electrical systems for heating, cooling and monitoring will support more efficient engines. Offsetting their hunger for power with electricity from waste heat will ensure that sustainability is maintained.