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Review of More Electric Engines for Civil Aircraft
Yixiong Liu,Da Mo,Devaiah Nalianda,Yiguang Li,Ioannis Roumeliotis 한국항공우주학회 2022 International Journal of Aeronautical and Space Sc Vol.23 No.4
More electric engines (MEEs) and more electric aircraft are mainly implemented to address the global warming issue and make engines more fuel efficient. Developing technology has made them applicable. This paper presents a detailed introduction to the MEE for civil aircraft, including its architecture, characteristics and performance, as well as the potential benefits of fuel consumption and emissions reduction. It is obvious that the adoption of electric components, such as active magnet bearings, electric starters and generators and electric fuel pumps, is beneficial. It is especially advantageous when mechanical, hydraulic and pneumatic systems with great weight and complex structures are eliminated. Moreover, the exploration of electric propulsion systems indicates that the potential profits are large and tempting. The challenges and technology bottlenecks for MEEs are also discussed. With the further development of battery and motor technology, the MEE will undoubtedly play a dominant role in the civil aircraft market.
Thermo-Mechanical Coupling Analysis of the Actuating Mechanism in a High Speed Press
Jin Cheng,Zhendong Zhou,Yixiong Feng,Zhenyu Liu,Yangyan Zhang 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.5
In order to ensure the manufacturing precision of an ultra-precision high speed press, an integrated thermo-mechanical coupling model of its actuating mechanism is proposed, which includes the mechanical models of the slider and crankshaft, the thermal models for calculating the heat generation powers at different bearings as well as the heat transfer and heat dissipation in the actuating mechanism. The validity of the proposed thermo-mechanical coupling model is verified by a thermal equilibrium experiment when the press operates under the full load of 3000kN at 300 rpm. A sensitivity analysis is conducted to investigate the simulation errors resulting from the variation of the ambient temperature, the results of which demonstrate that the average ambient temperature should be applied for improving simulation accuracy. Then the thermal stiffness of the actuating mechanism and the thermo-mechanical coupling characteristics of different parts are analyzed by the proposed model with the average ambient temperature applied. The influences of the thermally induced loads on the thermal stiffness are discussed in detail. It is concluded that the temperature rise of the actuating mechanism in the stamping process of a high speed press should be fully considered in the design phase for ensuring its manufacturing precision.
Dynamic Simulation and Aircraft Level Assessment of CMC Implementation on GTF Engine
Da Mo,Ioannis Roumeliotis,Yixiong Liu,Christos Mourouzidis,Sajal Kissoon 한국항공우주학회 2023 International Journal of Aeronautical and Space Sc Vol.24 No.3
This paper dynamically simulated the geared turbofan engine with CMC turbine components, including impacts of fuel schedule, shaft inertia, volume packing, BOV schedule. Deliberated comparisons were performed between CMC engine and Inconel engine on aircraft level performance and transient behaviour. Heat load examination is included in flight mission analysis, which lays the basis on the gearbox efficiency map related to torque and rotational speed. Results indicate that IPC surge margin of the CMC case slightly fall 0.15% but maintain steady. The mitigated T4 overshooting phenomenon has offered a 30 K drop and thus extended turbine life. More importantly, Fan shaft inertia dominantly affects engine operability, whereas the blow-off air fraction severely impacts the low power setting operation. Further investigation of heat load reveals that power loss at take-off segment accounts for 1.1% of IP shaft input power, which is 3.98% higher than Inconel case. The thermal management system needs to be redesigned to absorb extra heat. On assessment of aircraft level performance, CMC engine provides superior profits in maximizing airline revenue. The predicted annual fuel cost saving is about 0.08 million dollars coming from block fuel reduction. NOx, noise and CO2 demonstrate obvious decline, approaching 5.9%, 1.0% and 4.9%, respectively.