TY - GEN

T1 - A Study on Quantities Driving Maintenance, Repair, and Overhaul for Hybrid-Electric Aeroengines

AU - Schuchard, Lukas

AU - Bień, Maximilian

AU - Ziaja, Karl

AU - Blanken, Norman

AU - Göing, Jan

AU - Friedrichs, Jens

AU - di Mare, Francesca

AU - Ponick, Bernd

AU - Mailach, Ronald

N1 - Funding Information: This work is conducted as part of the joint research programme LuFo VI-1. It is supported by the German Federal Ministry of Economic Affairs and Climate Action under grant numbers 20E1913A, 20E1913B, 20E1913C, and 20E1913D. Funding Information: The authors would like to thank Yongtao Cao from Leibniz Universität Hannover for his contribution to this research effort. This work is conducted as part of the joint research pro-gramme LuFo VI-1. It is supported by the German Federal Ministry of Economic Affairs and Climate Action under grant numbers 20E1913A, 20E1913B, 20E1913C, and 20E1913D.

PY - 2024/2

Y1 - 2024/2

N2 - Hybrid-electric propulsion for commercial aircraft is currently a key industry interest. Consequently, publications on its design and performance estimation are manifold. However, models addressing characteristics of maintenance, repair, and overhaul (MRO) are virtually unavailable – even though direct maintenance costs (DMC) represent a significant part of direct operating costs in commercial aviation. Detailed analysis of hybrid-electric aircraft propulsion degradation and maintenance scenarios must integrate both methods of sizing and design as well as operational factors for conventional and electric subsystems, as operator-specific utilisation strongly influences MRO. Accordingly, a holistic engine analysis model is currently being developed using the example of an Airbus A320 aircraft, taking into account flight mission, engine performance, degradation, and MRO. This paper presents an implementation of hybridisation into the gas turbine thermodynamic cycle calculation for parallel hybrid-electric engine architectures with 2 and 5 MW electric motors, and the approach necessary for re-sizing hybridised gas turbine components. Turbomachinery loading throughout representative short-haul missions is analysed for conventional and hybrid-electric configurations based on the V2500 high-bypass turbofan engine, whereby unknown or uncertain boundary conditions are considered in a probabilistic sensitivity study. As a result, MRO-driving quantities such as engine performance parameters, atmospheric conditions, and ingested aerosols can be compared. The findings suggest that DMC related to the gas turbine may be considerably lowered through hybridisation, as it allows for reduced peak temperatures and more uniform gas turbine operation. However, these gains are at least partially offset by additional components’ DMC. For electric machines, bearings and the stator winding insulation are life-limiting; where the latter becomes increasingly dominant for higher power densities associated with high current densities and copper losses. Thermo-mechanical stresses are considered as driving mechanisms in power electronic systems degradation. Consequently, powerful lightweight machines must be balanced against tolerable thermal and electrical loads to achieve suitable service life.

AB - Hybrid-electric propulsion for commercial aircraft is currently a key industry interest. Consequently, publications on its design and performance estimation are manifold. However, models addressing characteristics of maintenance, repair, and overhaul (MRO) are virtually unavailable – even though direct maintenance costs (DMC) represent a significant part of direct operating costs in commercial aviation. Detailed analysis of hybrid-electric aircraft propulsion degradation and maintenance scenarios must integrate both methods of sizing and design as well as operational factors for conventional and electric subsystems, as operator-specific utilisation strongly influences MRO. Accordingly, a holistic engine analysis model is currently being developed using the example of an Airbus A320 aircraft, taking into account flight mission, engine performance, degradation, and MRO. This paper presents an implementation of hybridisation into the gas turbine thermodynamic cycle calculation for parallel hybrid-electric engine architectures with 2 and 5 MW electric motors, and the approach necessary for re-sizing hybridised gas turbine components. Turbomachinery loading throughout representative short-haul missions is analysed for conventional and hybrid-electric configurations based on the V2500 high-bypass turbofan engine, whereby unknown or uncertain boundary conditions are considered in a probabilistic sensitivity study. As a result, MRO-driving quantities such as engine performance parameters, atmospheric conditions, and ingested aerosols can be compared. The findings suggest that DMC related to the gas turbine may be considerably lowered through hybridisation, as it allows for reduced peak temperatures and more uniform gas turbine operation. However, these gains are at least partially offset by additional components’ DMC. For electric machines, bearings and the stator winding insulation are life-limiting; where the latter becomes increasingly dominant for higher power densities associated with high current densities and copper losses. Thermo-mechanical stresses are considered as driving mechanisms in power electronic systems degradation. Consequently, powerful lightweight machines must be balanced against tolerable thermal and electrical loads to achieve suitable service life.

KW - Degradation

KW - Hybrid-electric aircraft propulsion

KW - Maintenance

KW - MRO

UR - http://www.scopus.com/inward/record.url?scp=85172727449&partnerID=8YFLogxK

U2 - 10.1115/1.4063580

DO - 10.1115/1.4063580

M3 - Conference contribution

VL - 146

T3 - Proceedings of the ASME Turbo Expo

BT - Aircraft Engine

PB - American Society of Mechanical Engineers(ASME)

T2 - ASME Turbo Expo 2023: Turbomachinery Technical Conference and Exposition, GT 2023

Y2 - 26 June 2023 through 30 June 2023

ER -