This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Design of a Novel 2-Stroke SI Engine for Hybrid Light Aircraft
ISSN: 0148-7191, e-ISSN: 2688-3627
Published September 21, 2021 by SAE International in United States
This content contains downloadable datasetsAnnotation ability available
The trend of powertrain electrification is quickly spreading from the automotive field into many other sectors. For ultra-light aircraft, needing a total installed propulsion power up to 150 kW, the combination of a specifically developed internal combustion engine (ICE) integrated with a state-of-the-art electric system (electric motor, inverter and battery) appears particularly promising. The dimensions and weight of ICE can be strongly reduced (downsizing), so that it can operate at higher efficiency at typical cruise conditions; a large power reserve is available for emergency maneuvers; in comparison to a full electric airplane, the hybrid powertrain makes possible to fly at zero emissions for a much longer time, or with a much heavier payload. On the other hand, the packaging of a hybrid powertrain into existing aircraft requires a specific design of the thermal engine, that must be light, compact, highly reliable and fuel efficient. The last aspect has a direct impact on the performance of the aircraft, since the mission range depends on the capacity of the fuel tanks, which, in turn, is limited by the aircraft total weight.
The two-stroke cycle engine is far from a novelty for ultra-light aircraft; unfortunately, the specific fuel consumption and pollutant emissions of the conventional engines is quite high, in comparison to their 4-Stroke (4S) counterparts. The aim of the project presented in this paper is to develop a new type of 2-Stroke SI engine, able to match lightness, fuel efficiency and low pollutant emissions at a reasonable cost. The proposed ICE weights less than 60 kg, it delivers 110 kW@6000 rpm, along with a brake specific fuel consumption lower than 260 g/kWh in all the most relevant operating conditions.
The paper describes the design of the new engine, with particular attention to the optimization of the scavenging system (without poppet valves) and the design of a low pressure direct injection system. The process is supported by CFD 1D and 3D simulations. As far as the design of the injection system is concerned, the main goal was to obtain a fuel trapping ratio higher than 95%, along with a properly stratified charge at combustion onset, when considering the most critical operating condition (maximum engine speed and load). The main optimized parameters include the number of injectors, their locations, the injection timing and duration.
CitationCaprioli, S., Rinaldini, C., Mattarelli, E., Savioli, T. et al., "Design of a Novel 2-Stroke SI Engine for Hybrid Light Aircraft," SAE Technical Paper 2021-01-1179, 2021, https://doi.org/10.4271/2021-01-1179.
Data Sets - Support Documents
|Unnamed Dataset 1|
|Unnamed Dataset 2|
|Unnamed Dataset 3|
|Unnamed Dataset 4|
|Unnamed Dataset 5|
|Unnamed Dataset 6|
|Unnamed Dataset 7|
|Unnamed Dataset 8|
|Unnamed Dataset 9|
|Unnamed Dataset 10|
- Kompas , T. , Pham , V.H. , and Che , T.N. The Effects of Climate Change on GDP by Country and the Global Economic Gains From Complying With the Paris Climate Accord Earths Future 6 8 2018 1153 1173
- Oh , Y. , Park , J. , Lee , J.T. , Seo , J. et al. Estimation of CO2 Reduction by Parallel Hard-Type Power Hybridization for Gasoline and Diesel Vehicles Sci. Total Environ. 595 2017 2 12
- Doucette , R.T. and McCulloch , M.D. Modeling the Prospects of Plug-in Hybrid Electric Vehicles to Reduce CO2 Emissions Appl. Energy 88 7 2011 2315 2323
- Emadi , A. Power Electronics and Motor Drives in Electric, Hybrid Electric, and Plug-In Hybrid Electric Vehicles IEEE Trans. Ind. Electron. 55 6 2008 9
- Moore , M.D. , and Fredericks , B.
- Zhang , H. , Saudemont , C. , Robyns , B. , and Petit , M. Comparison of Technical Features between a More Electric Aircraft and a Hybrid Electric Vehicle 2008 IEEE Vehicle Power and Propulsion Conference 1 6 2008
- Bowman , C.L. , Felder , J.L. , and Marien , Ty.V. Turbo- and Hybrid-Electrified Aircraft Propulsion Concepts for Commercial Transport 2018 AIAA/IEEE Electric Aircraft Technologies Symposium (EATS) 1 8 2018
- Fletcher , S. , Flynn , M.-C. , Jones , C.E. , and Norman , P.J. Hybrid Electric Aircraft: State of the Art and Key Electrical System Challenges Transp. Electrification ENewsletter Sept 2016
- Brelje , B.J. and Martins , J.R.R.A. Electric, Hybrid, and Turboelectric Fixed-Wing Aircraft: A Review of Concepts, Models, and Design Approaches Prog. Aerosp. Sci. 104 2019 1 19
- Hoelzen , J. , Liu , Y. , Bensmann , B. , Winnefeld , C. et al. Conceptual Design of Operation Strategies for Hybrid Electric Aircraft Energies 11 1 2018 217
- Foxhall , N. Inside the New 850cc BRP-Rotax 2 Stroke DI Snowmobile Engine IFP Conference 2018
- Rinaldini , C.A. , Mattarelli , E. , and Golovitchev , V. CFD Analyses on 2-Stroke High Speed Diesel Engines SAE Int J Engines 4 2 2021 18
- Mattarelli , E. , Rinaldini , C.A. , and Wilksch , M. 2-Stroke High Speed Diesel Engines for Light Aircraft SAE Int. J. Engines 4 2 2011 2338 2360
- Sturm , S. , Lang , M. , and Schmidt , S. 9
- The Two-Stroke Cycle Engine: Its Development, Operation, and Design Routledge 2017
- Mattarelli , E. and Rinaldini , C. Two-Stroke Gasoline Engines for Small-Medium Passenger Cars SAE Technical Paper 2015-01-1284 2015 https://doi.org/10.4271/2015-01-1284
- Balduzzi , F. , Vichi , G. , Romani , L. , Ferrara , G. et al. Development of a Low Pressure Direct Injection System for a Small 2S Engine. Part I - CFD Analysis of the Injection Process SAE Int. J. Engines 8 4 2015 1885 1897 https://doi.org/10.4271/2015-01-1727
- Romani , L. , Vichi , G. , Ferrara , G. , Balduzzi , F. et al. Development of a Low Pressure Direct Injection System for a Small 2S Engine. Part II - Experimental Analysis of the Engine Performance and Pollutant Emissions SAE Technical Paper 2015-01-1730 2015 https://doi.org/10.4271/2015-01-1730
- Krimplstätter , S. , Winkler , F. , Oswald , R. , and Kirchberger , R. Air Cooled 50cm3 Scooter Euro 4 Application of the Two-Stroke LPDI Technology SAE Technical Paper 2014-32-0008 2014 https://doi.org/10.4271/2014-32-0008
- Oswald , R. , Ebner , A. , and Kirchberger , R. High Efficient 125- 250 cm3 LPDI Two-Stroke Engines, a Cheap and Robust Alternative to Four-Stroke Solutions? SAE Technical Paper 2010-32-0019 2010 https://doi.org/10.4271/2010-32-0019
- Winkler , F. , Oswald , R. , Schögl , O. , Abis , A. et al. 3 12