Development of the world’s first Aircraft jet engine-embedded electric machine with high power density and heat resistant ～For optimizing the energy management of aircraft system to reduce CO2 emission～
IHI Corporation (Headquarter: Tokyo, Japan, CEO: Tsugio Mitsuoka, hereinafter referred to as “IHI”) leads More Electric Architecture for Aircraft and Propulsion (hereinafter referred to as “MEAAP”) that aims at the optimization of the total energy management of aircraft system with technological innovation toward CO2 emission reduction from aviation. As one of the key technology to realize the MEAAP system, IHI developed an electric machine (250kW) that can be mounted inside the tail cone located in the aircraft jet engine rear-end in cooperation with domestic companies, and successfully completed the evaluation testing in this February.
This development was conducted as one of Research and Development Project for Advanced Aircraft Systems toward Practical Application supported by New Energy and Industrial Technology Development Organization（NEDO） (Director: Hiroaki Ishizuka).
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| Illustration of Engine Embedded Electric Machine (E3M) | E3M |
[Background of the development]
While the number of aircraft in fleet is expected to be doubled in the next 20 years due to a rapid increment of aircraft passengers, the International Air Transport Association (IATA) sets a target of a reduction in net aviation CO2 emissions of 50% by 2050, relative to 2005 levels. In order to achieve it, we should not only improve conventional technology, but also realize the innovative aircraft system that reduces environmental impact dramatically while maintaining the aircraft safety and economical aspect.
MEAAP focuses on the significant improvement in fuel efficiency by optimizing the aircraft system considering propulsion, thermal management and electrical power management. In addition, changing the conventional hydraulic, pneumatic and mechanical systems into electric systems brings significant improvement of maintenance ability and system weight reduction. IHI collaborates with domestic and international partners on various R&D to realize the MEAAP system.
[Developed Technology]
One of the biggest technical challenges is development of an electric generator which can accommodate enlarged electrical power demand used in future aircraft. In order to reduce a mechanical loss and aerodynamic loss due to the gear train connecting the engine main shaft and generator, changing the generator installation method has been studied. IHI focused on the electric generator directly mounted to the engine main shaft, and determined the location as the engine rear-end, because engine tail cone space is the best location considering the operability and maintenance ability. However, the environmental conditions such as engine vibration, shock and temperature from exhaust gas path are harsh for electrical components and its thermal and structural design is unfeasible without innovative and unique technology.
IHI developed the cutting-edge technology which enables the high power density and heat resistant generator, including pre-shaped and weld-jointed windings with 300 deg. C high heat-resistant insulation coating. Additionally, new cooling technology based on IHI’s expertise and experiences on the thermal, aerodynamic and structural technology for the jet engines was incorporated. By combining these technology, IHI developed the electric machine that can be directly mounted to the engine shaft at the engine rear-end. The power generation testing was conducted at IHI Yokohama facility and we achieved 250kW rated power generation in February.
[Future plan]
IHI is studying innovative technology and optimization of energy management for the future electrified aircraft aiming at introduction of the MEAAP concept in 2030s. IHI accelerates the development of the high power density electric machine including an actual engine demonstration, and also considers the possibility of much higher power generation system, which may be a key technology for future hybrid propulsion.
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| A concept of More Electric Architecture for Aircraft and Propulsion “MEAAP” |