2020 AIAA/IEEE Electric Aircraft Technologies Symposium (EATS)最新文献

{"title":"Multi-Point Design of Parallel Hybrid Aero Engines","authors":"M. Sielemann, Clément Coïc, Xin Zhao, Dimitra Eirini Diamantidou, K. Kyprianidis","doi":"10.2514/6.2020-3556","DOIUrl":"https://doi.org/10.2514/6.2020-3556","url":null,"abstract":"A parallel hybrid configuration is a feasible means to reduce fuel consumption of gas turbines propelling aircraft. It introduces an electric drive on one of the spools of the gas turbine, typically the low pressure spool. The electric drive is supplied by a battery, which can also be charged when excess power is available (for instance during conditions requiring handling bleed in conventional designs). It also requires a thermal management system to dissipate heat away from electric components. While the scientific literature describes parallel hybrid studies and anticipated benefits assuming various future entry into service dates, there is limited information on the design of the gas turbine component of such a system. For conventional gas turbines, multi-point design schemes are used. This paper describes, in a consistent fashion and based on a formalized notation, how such multi-point design schemes are applied to parallel hybrid aero engines. It interprets published approaches, fills gaps in methodology descriptions with meaningful assumptions and summarizes design intent. It also discusses cycle designs generated by different methodologies based on the same cycle model. Results show that closure equations prescribing boost power can be preferable over closure equations prescribing temperature ratios for uniqueness and engineering intuitiveness while the latter can be beneficial in a second step for design space exploration.","PeriodicalId":403355,"journal":{"name":"2020 AIAA/IEEE Electric Aircraft Technologies Symposium (EATS)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132547002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Distributed Electric Propulsion on the Performance of a General Aviation Aircraft","authors":"M. Gallani, L. Góes, Luiz Augusto Rodrigues Nerosky","doi":"10.2514/6.2020-3594","DOIUrl":"https://doi.org/10.2514/6.2020-3594","url":null,"abstract":"With an always increasing demand for more efficient aircraft due to both economic and environmental purposes, academy and industry are studying hybrid-electric and full-electric concepts to explore new aircraft design opportunities. This paper proposes a study based on a Cessna 208B Grand Caravan, using it as a platform to implement distributed electric propulsion and enable the use of high-lift propellers by electrifying the propulsive system. Key design parameters of the aircraft are varied to evaluate the effectiveness of the lift augmentation system as well as its effects on generated thrust and aerodynamic efficiency. The effects of the propellers slipstreams on the wing are implemented on SUAVE, a conceptual level design environment, which is used to integrate the aircraft model and run the simulations. Results of the analyses differ from what is available on the literature, yielding aerodynamic efficiency gains that are much more modest than what was expected according to assumptions made on recent publications.","PeriodicalId":403355,"journal":{"name":"2020 AIAA/IEEE Electric Aircraft Technologies Symposium (EATS)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115480489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of the Impact of an Advanced Power System on a Turboelectric Single-Aisle Concept Aircraft","authors":"Sydney L. Schnulo, Jeffryes W. Chapman, Patrick Hanlon, Hashmatullah Hasseeb, R. Jansen, David J. Sadey, E. Sozer, J. Jensen, D. Maldonado, K. Bhamidipati, Nicole Heersema, Kevin R. Antcliff, Zachary J. Frederick, J. Kirk","doi":"10.2514/6.2020-3548","DOIUrl":"https://doi.org/10.2514/6.2020-3548","url":null,"abstract":"Electrified aircraft propulsion concepts show potential in using propulsion airframe integration to decrease fuel burn and emissions. Even though electrification offers component efficiency values greater than 90 percent, at high power levels this results in the generation of significant amounts low grade waste heat. A major challenge of electrified aircraft propulsion is managing that heat while minimizing any penalties associated with a thermal management system. This paper explores the potential benefit of power distribution and thermal management innovations at the aircraft system level demonstrated on a turboelectric single-aisle concept. The first innovation is high-efficiency components that eliminate over half of the waste heat. The second takes advantage of the outer mold line of the aircraft to reject heat directly to the environment passively, instead of adding active cooling loops that negatively impact the weight, power, and drag of the aircraft. In order to fully grasp the impact of the advanced power system, we develop methods of modeling the power and thermal management systems to be integrated in the full aircraft conceptual model. In our first model, which acts as a baseline for our study, the aircraft is designed with a state of the art DC power system and active cooling loops. Our second model includes an advanced power system with active cooling, which results in a fuel burn reduction of 2.5 percent. Finally, in our third model, we assess the benefit of an outer mold line cooling scheme with the advanced power system. The outer mold line cooling scheme with an advanced power system yields an additional 0.8 percent reduction in fuel burn, for an overall fuel burn reduction potential of 3.3 percent in addition to aerodynamic benefits from propulsion airframe integration enabled by electrified aircraft propulsion.","PeriodicalId":403355,"journal":{"name":"2020 AIAA/IEEE Electric Aircraft Technologies Symposium (EATS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130612598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modular Three-level T-type Power Electronics Building Block for Aircraft Electric-Propulsion Drives","authors":"A. Deshpande, Y. Chen, B. Narayanasamy, Z. Yuan, F. Luo","doi":"10.2514/6.2020-3595","DOIUrl":"https://doi.org/10.2514/6.2020-3595","url":null,"abstract":"The power electronics drives for electric propulsion in more-electric aircraft need to highly efficient and power-dense. Moreover, a modular approach to the drive’s construction ensures reduced costs, reliability, and ease of maintenance. In this paper, the design and development of a modular power electronics building block (PEBB) in a dc-ac three-level t-type single phase-leg topology is presented. The designed PEBB is capable of 100-kW power processing and suitable for 1-kV dc-link. A hybrid switch consisting of a silicon IGBT and silicon carbide MOSFET was used as the switching device in the PEBB. The hybrid switch enables high switching frequencies at high-power than the conventional silicon IGBT. A model-based design tool facilitated the topology and semiconductor selection for high conversion efficiency and lightweight. Due to the unavailability of commercial three-level t-type power modules, a PCB- and off-the-shelf discrete semiconductor-based high-power switch was designed for the neutral point clamping. A non-trivial design of an aluminum-based multilayer laminated busbar, a key element in the PEBB, was the primary focus of the work. The busbar had symmetrical low-inductance commutation loops, and the value was in the range of 28 - 29 nH. The block’s specific-power and volumetric power density were estimated to be 27.7 kW/kg and 308.61 W/in3, respectively. Finally, the block’s continuous operation was demonstrated at 48 kVA, and the efficiency of the block was 98.2%.","PeriodicalId":403355,"journal":{"name":"2020 AIAA/IEEE Electric Aircraft Technologies Symposium (EATS)","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115960345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic System Modeling and Stability Assessment of an Aircraft Distribution Power System using Modelica and FMI","authors":"Stavros Konstantinopoulos, H. Nademi, L. Vanfretti","doi":"10.2514/6.2020-3544","DOIUrl":"https://doi.org/10.2514/6.2020-3544","url":null,"abstract":"In this work, the electrical distribution system of a Boeing 747 aircraft is implemented in Modelica. The electrical system is modeled in detail as far as generation and loads are concerned, aiming to capture any relevant dynamics and instabilities that can ensue during the aircraft’s operation; while the power electronic interfaces of the loads are represented using averaged models. Small signal analysis is conducted at different operating points, aiming to capture relevant dynamics. Additionally, small signal analysis and time domain simulations are carried out to identify operational regions where low damping of unstable oscillations can occur, in order to characterize control loops interactions and system states. Finally, this paper proposes countermeasures for load startup and required controls that can alleviate any potential instabilities.","PeriodicalId":403355,"journal":{"name":"2020 AIAA/IEEE Electric Aircraft Technologies Symposium (EATS)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133283815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Descent Angle Control by Regenerative Air Brake Using Observer-based Thrust Control for Electric Aircraft","authors":"Kentaro Yokota, H. Fujimoto, Y. Hori","doi":"10.2514/6.2020-3566","DOIUrl":"https://doi.org/10.2514/6.2020-3566","url":null,"abstract":"Research and development have been very active in electric aircraft (EA). EA use electric motors as the power source; therefore, EA are expected to achieve more secure, more efficient, and more eco-friendly aviation. Electric motors enable EA to regenerate their potential energy while descending as the windmilling propeller produces negative torque and thrust. This paper proposes descent angle control method by using windmilling propeller as an alternative to mechanical air brakes. In addition, the use of wide range of propeller pitch angle is discussed in order to produce enough drag to eliminate mechanical air brakes. The effectiveness of the proposed method is verified by simulations and experiments in the wind tunnel.","PeriodicalId":403355,"journal":{"name":"2020 AIAA/IEEE Electric Aircraft Technologies Symposium (EATS)","volume":"11 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134560776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Initial Steps in Modeling of CHEETA Hybrid Propulsion Aircraft Vehicle Power Systems using Modelica","authors":"Meaghan Podlaski, L. Vanfretti, Abhijit Khare, H. Nademi, Phillip J. Ansell, K. Haran, T. Balachandran","doi":"10.2514/6.2020-3580","DOIUrl":"https://doi.org/10.2514/6.2020-3580","url":null,"abstract":"The aviation industry has been challenged to increase the sustainability of its technologies, which is the main driving force in research and exploration of fully electrified propulsion. This paper presents the initial steps in the design and modeling of the Cryogenic High-Efficiency Electrical Technologies for Aircraft (CHEETA) that would form the basis for hybrid-electric aircraft power systems. To this end, different power system configurations for fully electrified propulsion are proposed and analyzed. Novel, multi-domain components used in both the power system model and the cryogenic thermal system model are introduced and explained in detail. This paper also presents initial results for the different power system configurations under steady-state conditions.","PeriodicalId":403355,"journal":{"name":"2020 AIAA/IEEE Electric Aircraft Technologies Symposium (EATS)","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127429036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Outer Mold Line Cooled Electric Motors for Electric Aircraft","authors":"Thomas F. Tallerico, Andrew D. Smith, Jerald T. Thompson, E. L. Pierson, C. Hilliker, David Avanesian, Wesley A. Miller, Kyle W. Monaghan","doi":"10.2514/6.2020-3573","DOIUrl":"https://doi.org/10.2514/6.2020-3573","url":null,"abstract":"To be viable alternatives to traditional aircraft, electric aircraft require electric propulsion motors with high specific power, efficiency, and reliability. Motor thermal management is key to developing electric motors that meet these requirements, because increasing motor power density generally increases motor loss density, motor efficiency improves as motor temperature is reduced, and motor winding life is directly related to peak winding temperature. Liquid cooling loops, heat sinks, internal flow, and heat exchangers can all be used to cool electric motors on electric aircraft; however, these components add mass, losses, complexity, and drag to an aircraft. The question in the design of an electric aircraft’s drive system therefore becomes how to trade motor performance versus the size, mass, power, and complexity of the thermal management system. This paper seeks to answer the question of what motor performance can be achieved at one extreme end of this motor vs thermal management system trade space where no explicit thermal management system or features are used to cool the motor. This task is completed by designing motors for electric aircraft that are cooled only by the propeller wake on the outer mold line (OML) of the nacelles they sit in and therefore have no thermal management system. A prototype motor designed for NASA’s Maxwell X-57 aircraft is used to inform the development of an OML cooled motor design tool. That tool is used to produce a high fidelity OML cooled motor design for X-57 that achieves >96% efficiency at a total mass of ~25.5 kg. The design tool is then used to evaluate the possible performance of OML cooled electric motors for various power levels and thermal environments.","PeriodicalId":403355,"journal":{"name":"2020 AIAA/IEEE Electric Aircraft Technologies Symposium (EATS)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129171488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predicting Fleet-level Carbon Emission Reductions from Future Single-Aisle Hybrid Electric Aircraft","authors":"Samarth Jain, W. Crossley","doi":"10.2514/6.2020-3554","DOIUrl":"https://doi.org/10.2514/6.2020-3554","url":null,"abstract":"With rising concerns over commercial aviation’s contribution to global carbon emissions, there exists a tremendous pressure on the aviation industry to find advanced technological solutions for reducing its share of CO2 emissions. A potential solution to mitigate this global emissions crisis is to operate fully-electric aircraft; however, the current battery technology is forcing the industry to explore partially electrified aircraft as a possible mid-term solution. There exist a number of studies that look at the potential CO2 emissions benefits possible from hybrid electric and turboelectric aircraft. Although these studies show encouraging results about the potential reduction in carbon emissions at an aircraft level, none of the studies – to the authors’ best knowledge – discuss the potential fleet-level impacts of introducing these partially electrified aircraft in an airline fleet. This paper focuses on predicting the fleet-level environmental impacts of a notional, future single-aisle parallel hybrid electric aircraft with a 900 nautical mile range. The work demonstrates an approach to make these predictions by modeling the behavior of a profit-seeking airline (with a mixture of conventional all Jet-A fuel burning and hybrid electric aircraft in its fleet) using the Fleet-Level Environmental Evaluation Tool (FLEET). FLEET’s model-based predictions rely upon historically-based information about US-touching airline routes and passenger demand served by US flag-carrier airlines from the Bureau of Transportation Statistics to initiate model-based predictions of future demand, aircraft fleet mix, and aircraft operations. Using a simplistic model for representing the behavior of a single-aisle parallel hybrid electric aircraft, the FLEET simulation predicts the changes in the fleet-wide carbon emissions due to the introduction of this new aircraft in an airline fleet in the year 2035. By 2065, FLEET results predict that the fleet-wide CO2 emissions with hybrid electric aircraft in the fleet mix are about 15.9% lower than the fleet-wide CO2 emissions of a conventional (all Jet-A fuel burning) aircraft-only airline. Because of the reduced range capability of the hybrid electric aircraft relative to a conventional aircraft of similar size, the simulation results indicate that the airline changes the usage, acquisition and retirement of its conventional aircraft when hybrid electric aircraft are available; this is most notable to serve passenger demand on certain predominantly single-aisle service routes that cannot be flown by the future single-aisle hybrid electric aircraft.","PeriodicalId":403355,"journal":{"name":"2020 AIAA/IEEE Electric Aircraft Technologies Symposium (EATS)","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133319620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal Management System Design for Electrified Aircraft Propulsion Concepts","authors":"Jeffryes W. Chapman, Hashmatullah Hasseeb, Sydney L. Schnulo","doi":"10.2514/6.2020-3571","DOIUrl":"https://doi.org/10.2514/6.2020-3571","url":null,"abstract":"This paper describes the development of thermal management systems (TMS) for three electrified aircraft propulsion (EAP) vehicle concepts released by NASA that span the UAM, regional, and single-aisle markets. For each EAP concept, a conventional TMS is designed for two electric component technology levels: state of the art and advanced. The goals for the paper are to compare the TMS designs for the above EAP concepts, to study how changes in requirements affect the TMS subcomponents, and to develop generalized TMS sizing relations. Each conventional TMS concept utilizes a liquid-based cooling methodology and is designed to cool the EAP electrical components only. The design parameters considered in this study include TMS architecture variation due to differing vehicle cooling requirements, electrical component efficiencies, vehicle total fuel burn or energy consumption, and electrical component operating temperatures. Results show that cooling components with low temperature limits increases TMS weight and demonstrate that efficiency gains of the specific technologies can net a lower weight TMS system despite more stringent temperature limits.","PeriodicalId":403355,"journal":{"name":"2020 AIAA/IEEE Electric Aircraft Technologies Symposium (EATS)","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125752378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}