Life Cycle Analysis for a Powertrain in a Concept for Electric Power Generation in a Hybrid Electric Aircraft

Author(s):  
Michael Schneider ◽  
Jens Dickhoff ◽  
Karsten Kusterer ◽  
Wilfried Visser

Abstract In the recent decades, civil aviation was growing 4.7% per annum. In order to reduce emissions promoting the global warming process, alternative propulsion systems are needed. Full-electric propulsion systems in aviation might have the potential for emission-free flights using renewable energy. However, several research efforts indicate electric propulsion only seems feasible for small aircraft. Especially due to the low energy density of batteries compared to fossil fuels. For this reason, hybrid propulsion systems came into focus, combining the benefits of all-electric and conventional propulsion system concepts. It is also considered as bridging technology, system test and basis for component development — and therewith paves the way towards CO2 free aviation. In the ‘HyFly’ project (supported by the German Luftfahrtforschungsprogramm LuFo V-3), the potential of a hybrid electric concept for a short/mid-range 19 PAX aircraft is assessed — not only on system but also on single component basis. In a recent study, the propulsion architecture and the operating mode of the gas turbine and the electric components have been defined [1]. In this paper, the advantages of the hybrid propulsion architecture and a qualitative assessment of component life are presented. Methods for life time prediction for the aircraft engine, the electric motor, the reluctance generator and the battery are discussed. The impact of turbine inlet temperature on life consumption is analyzed. The life cycle of the aircraft engine and the electric components including gradual component deterioration and consequent performance degradation is simulated by using an in-house gas turbine simulation tool (GTPsim). Therefore, various effects on electric propulsion system can be predicted for the entire drivetrain system in less than one hour.

2019 ◽  
Vol 123 (1268) ◽  
pp. 1602-1617 ◽  
Author(s):  
Hendrik Gesell ◽  
Florian Wolters ◽  
Martin Plohr

ABSTRACTThe increasing environmental requirements in the air transport sector pose great challenges to the aviation industry and are key drivers for innovation. Besides various approaches for increasing the efficiency of conventional gas turbine engines, electric propulsion systems have moved into the focus of aviation research. The first electric concepts are already in service in general aviation. This study analyses the potentials of electric and turbo hybrid propulsion systems for commercial aviation. Its purpose is to compare various architectures of electrical powertrains with a conventional turboprop on a regional aircraft, similar to the ATR 72, on engine and flight mission levels. The considered architectures include a turbo-electric (power controlled and direct driven), hybrid-electric (serial and parallel) and a pure electric concept. Their system weights are determined using today’s technology assumptions. With the help of performance models and flight mission calculations the impact on fuel consumption, CO ${}_{2}$ emissions and aircraft performance is evaluated.


2021 ◽  
Vol 9 (2) ◽  
pp. 186
Author(s):  
Francesco Mauro ◽  
Elia Ghigliossi ◽  
Vittorio Bucci ◽  
Alberto Marinó

Nowadays, sustainable navigation is becoming a trending topic not only for merchant ships but also for pleasure vessels such as motoryachts. Therefore, the adoption of a hybrid-electric propulsion system and the installation of on-board storage devices could increase the greenness of a megayacht. This paper analyses the performance of three commercial propulsive solutions, using a dynamic operative profile and considering the influences of the smart berthing infrastructures. Results compare the yearly fuel consumptions of the analysed configurations for a reference megayacht.


2021 ◽  
Vol 5 ◽  
pp. 164-176
Author(s):  
Stavros Vouros ◽  
Mavroudis Kavvalos ◽  
Smruti Sahoo ◽  
Konstantinos Kyprianidis

Hybrid-electric propulsion has emerged as a promising technology to mitigate the adverse environmental impact of civil aviation. Boosting conventional gas turbines with electric power improves mission performance and operability. In this work the impact of electrification on pollutant emissions and direct operating cost of geared turbofan configurations is evaluated for an 150-passenger aircraft. A baseline two-and-a-half-shaft geared turbofan, representative of year 2035 entry-into-service technology, is employed. Parallel hybridization is implemented through coupling a battery-powered electric motor to the engine low-speed shaft. A multi-disciplinary design space exploration framework is employed comprising modelling methods for multi-point engine design, aircraft sizing, performance and pollutant emissions, mission and economic analysis. A probabilistic approach is developed considering uncertainties in the evaluation of direct operating cost. Sensitivities to electrical power system technology levels, as well as fuel price and emissions taxation are quantified at different time-frames. The benefits of lean direct injection are explored along short-, medium-, and long-range missions, demonstrating 32% NO<italic><sub>x</sub></italic> savings compared to traditional rich-burn, quick-mix, lean-burn technologies in short-range operations. The impact of electrification on the enhancement of lean direct injection benefits is investigated. For hybrid-electric powerplants, the take-off-to-cruise turbine entry temperature ratio is 2.5% lower than the baseline, extending the corresponding NO<italic><sub>x</sub></italic> reductions to the level of 46% in short-range missions. This work sheds light on the environmental and economic potential and limitations of a hybrid-electric propulsion concept towards a greener and sustainable civil aviation.


Author(s):  
Ioannis Roumeliotis ◽  
Lorenzo Castro ◽  
Soheil Jafari ◽  
Vassilios Pachidis ◽  
Louis De Riberolles ◽  
...  

Abstract Future aircraft and rotorcraft propulsion systems should be able to meet ambitious targets and severe limitations set by governments and organizations. These targets cannot be achieved through marginal improvements in turbine technology or vehicle design. Hybrid-electric propulsion is being widely considered as a revolutionary concept to further improve the environmental impact of air travel. One of the most important challenges and barriers in the development phase of hybrid-electric propulsion systems is the Thermal Management System (TMS) design, sizing and optimization for addressing the increased thermal loads due to the electric power train. The aim of this paper is to establish an integrated simulation framework including the vehicle, the propulsion system and the fuel-oil system (FOS) for assessing the cooling capability of the FOS for the more electric era of rotorcrafts. The framework consists of a helicopter model, propulsion system models, both conventional and hybrid-electric, and a FOS model. The test case is a twin-engine medium (TEM) helicopter flying a representative Passenger Air Transport (PAT) mission. The conventional power plant heat loads are calculated and the cooling capacity of the FOS is quantified for different operating conditions. Having established the baseline, three different Power Management Strategies (PMS) are considered and the integrated simulation framework is utilized for evaluating FOS temperatures. The results highlight the limitations of existing rotorcraft FOS to cope with the high values of thermal loads associated with hybridization for the cases examined. Hence, new ideas and embodiments should be identified and assessed. The case of exploiting the fuel tank as a heat sink is investigated and the results indicate that recirculating fuel to the fuel tank can enhance the cooling capacity of conventional FOS.


2019 ◽  
Author(s):  
V Bolbot ◽  
G Theotokatos ◽  
E Boulougouris ◽  
D Vassalos

Cruise ship industry is rapidly developing, with both the vessels size and number constantly growing up, which renders ensuring passengers, crew and ship safety a paramount necessity. Collision, grounding and fire are among the most frequent accidents on cruise ships with high consequences. In this study, a hazard analysis of diesel-electric and hybrid-electric propulsion system is undertaken using System-Theoretic Process Analysis (STPA). The results demonstrate significant increase in potential hazardous scenarios due to failures in automation and control systems, leading to fire and a higher number of scenarios leading to propulsion and power loss in hybrid-electric propulsion systems than on a conventional cruise-ship propulsion system. Results also demonstrate that STPA enhancement is required to compare the risk of two propulsion systems.


2021 ◽  
pp. 1-19
Author(s):  
Yi Zhou ◽  
Kayvan Pazouki ◽  
Rosemary Norman

Abstract With the effects of global warming, the North Sea Route has become an economic option for cargo transportation because of the shorter distance between East Asia and Europe. Generally, conventional mechanical propulsion systems installed in ice-capable tankers suffer from significant drawbacks because of poor fuel efficiency when sailing at low speed, therefore, advanced technologies have been applied such as diesel electric and nuclear-powered propulsion; however, drawbacks still exist. Hybrid propulsion is a more environmental-friendly, economical solution for ships with icebreaking capability, which can address the drawbacks in both diesel electric and nuclear power systems. In this paper, modeling of system components is presented and implemented in MATLAB Simulink. A primary control strategy is applied to the system to ensure system stability, and an advanced secondary strategy is developed and applied to the power sources to minimize fuel consumption. Given two scenarios, the simulation results of the hybrid propulsion system developed in this research and those of diesel electric propulsion systems with DC and AC distribution systems are compared and indicate that the hybrid system can offer up to 22.4% fuel savings over ice-loading condition, and 39.5% fuel reduction over the particular voyage of varying speed in open water is applied in this paper. Introduction In recent years, some sea routes that were previously blocked by ice have become increasingly accessible in the warmest months of the year due to the effects of global warming. Researchers have estimated that, by 2030, the percentage of Arctic shipping will have increased to 25% of cargo trade between Europe and Asia (Lasserre 2019). Northern Sea Route (NSR) shipping provides benefits for international trade, but challenges still exist. Increasing carbon emissions have seriously impacted the Arctic environment (Hassol & Corell 2006). Table 1 shows the total number of ships using Heavy Fuel Oil (HFO) in Arctic waters in 2015, and associated black carbon emissions, as published by the IMO (Comer et al. 2017). As it is shown, oil tankers made up just 4.5% of all ships entering Arctic waters but despite their low proportion, they were responsible for 17% of black carbon emissions. Thus, an environmentally friendly and fuel-efficient propulsion system to reduce these emissions from tankers trading in Arctic waters is required.


Electronics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 879
Author(s):  
Gianfranco Rizzo ◽  
Shayesteh Naghinajad ◽  
Francesco Tiano ◽  
Matteo Marino

Hybrid Electric Vehicles (HEVs) can be divided into three categories according to how the two propulsion systems (the thermal and the electric ones) supply the driving torque to the vehicle. When the torque is supplied only by an electric propulsion system, while the heat engine takes care of generating the electricity needed to operate the system, it is called a hybrid-series. Conversely, when both propulsion systems provide torque, the vehicle is identified with parallel hybrid wording. Among the parallel hybrids there is a particular configuration called Through-the-Road (TTR). In this configuration, the two propulsion systems are not mechanically connected to each other, but it is precisely the road that allows hybrid propulsion. This architecture, dating back to the early twentieth century, is still used by several manufacturers and carries with it peculiar configurations and control methods. It is also a configuration that fits well with the transformation of conventional vehicles into a hybrid. The paper presents a survey of the TTR HEV solution, evidencing applications, potentialities and limits.


Author(s):  
Jo Köhler ◽  
Peter Jeschke

AbstractThis paper presents a novel conceptual design method for electric and hybrid electric propulsion systems in small aircraft. The effects of key design parameters on the propulsion system performance are analyzed and the advantages and drawbacks of the investigated propulsion systems are discussed on the basis of two sets of thrust requirements. First, the general conceptual design algorithm is outlined. This is followed by a description of the three propulsion systems investigated: the fully electric; the parallel hybrid; and the conventional internal combustion engine. Scalable models of all required propulsion system components are presented, including weight estimation and operating characteristics. Afterwards, the conceptual design algorithm is exemplified for a reference two-seater motorized glider with a cruising speed of 140 kt and a maximum take-off mass of 1000 kg. Key design parameters are identified and their impact on propulsion system mass and cruise efficiency discussed. This study suggests that the parallel hybrid propulsion system is advantageous for high power ratios between take-off and cruise. For a power ratio of 4.5, either a relative cruise efficiency advantage of 12% or a maximum system mass advantage of 10% can be expected, depending on the propeller design. For the chosen cruise range of 300 km, the system mass of the fully electric propulsion system is at least 2.37 times higher when compared to the conventional propulsion system. In summary, a design method for hybrid electric propulsion systems is presented here which may be used for conceptual design. Furthermore, the suitability of the propulsion systems under investigation for different sets of thrust requirements is assessed, which may be helpful for aircraft designers.


2021 ◽  
Author(s):  
Sangkeun Kang ◽  
Ioannis Roumeliotis ◽  
Jinning Zhang ◽  
Vassilios Pachidis ◽  
Olivier Broca

Abstract This paper aims to assess the gas turbine operability and overall hybrid electric propulsion system performance for a parallel configuration applied to a 150 passenger single-aisle aircraft. Two arrangements are considered: one where the low pressure shaft is boosted and one where the high pressure shaft is boosted. For identifying limits in the hybridization strategy steady state and transient operation are considered and the hybridization effect on compressor operability is determined. Having established the electric power on-take limits with respect to gas turbine operation the systems performance at aircraft level is quantified for the relevant cases. Different power management strategies are applied for the two arrangements and for different power degrees of hybridization. The results indicate that despite the fact that pollutant emission and fuel consumption may improved for hybrid propulsion, this comes at the cost of reduced payload and operability margins. Boosting the low pressure shaft may give the highest engine performance benefits but with a significant weight penalty, while the low pressure compressor system operability is negatively affected. On the other hand boosting the high pressure shaft provides lower engine performance benefits but with smaller weight penalty and with less operability concerns.


Author(s):  
Kenneth L. Suder

Abstract Given the maturity of the gas turbine engine since its invention and also considering the limited and flattened level of resources expected to be allocated for NASA aeronautics research and development, we ask the question are NASA technology investments still needed to enable future turbine engine-based propulsion systems? If so, what is NASA’s unique role to justify NASA’s investment? To address this topic, we will first review the accomplishments and the impact that NASA Glenn Research Center has made on turbine engine technologies over the last 78 years. Specifically, this paper discusses NASA’s role and contributions to turbine engine development, specific to both 1) NASA’s role in conducting experiments to understand flow physics and provide relevant benchmark validation experiments for Computational Fluid Dynamics (CFD) code development, validation, and assessment; and 2) the impact of technologies resulting from NASA collaborations with industry, academia, and other government agencies. Note that the scope of the discussion is limited to the NASA technology contributions with which the author was intimately associated, and does not represent the entirety of the NASA contributions to turbine engine technology. The specific research, development, and demonstrations discussed herein were selected to both 1) provide a comprehensive review and reference list of the technology and its impact, and 2) identify NASA’s unique role and highlight how NASA’s involvement resulted in additional benefit to the gas turbine engine community. Secondly, we will discuss current NASA collaborations that are in progress and provide a status of the results. Finally, we discuss the challenges anticipated for future turbine engine-based propulsion systems for civil aviation and identify potential opportunities for collaboration where NASA involvement would be beneficial. Ultimately, the gas turbine engine community will decide if NASA involvement is needed to contribute to the development of the design and analysis tools, databases, and technology demonstration programs to meet these challenges for future turbine engine-based propulsion systems.


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