Design of a novel 2-Stroke SI engine for hybrid light aircraft Universita di Modena e Reggio Emilia

Format:

Book

Conference/Event

Author/Creator:

Caprioli, Stefano, author.

Contributor:

Mattarelli, Enrico

Rinaldini, Carlo

Savioli, Tommaso

Scrignoli, Francesco

Conference Name:

SAE Powertrains, Fuels & Lubricants Digital Summit (2021-09-28 : Live Online, Pennsylvania, United States)

Language:

English

Physical Description:

1 online resource cm

Place of Publication:

Warrendale, PA SAE International 2021

Summary:

The trend of powertrain electrification is quickly spreading from the automotive field into many other sectors. In particular, the combination of a specifically developed thermal engine integrated with a state-of-the-art electric system (motor, inverter and battery) appears very promising for ultra-light aircraft, needing a total installed propulsion power up to 150 kW. The addition of the electric motor (EM) yields a number of advantages: downsizing or down-speeding of the internal combustion engine (ICE), availability of a large propulsion power reserve for any emergency manouver, capability to fly at zero emissions, et cetera For this type of hybrid powertrains, a fundamental advantage is the high power-to-weight ratio of the internal combustion engine, associated to an excellent thermal efficiency. The last aspect has a direct impact on the performance of the aircraft, since the mission range is related to the capacity of the fuel tanks, which generally take a relevant share of the total aircraft weight.The two-stroke cycle engine is far from a novelty for ultra-light aircraft; however, the fuel efficiency of conventional engines is quite poor, in comparison to their 4-stroke counterparts. Therefore, the Blu Spark project, funded by the European Research and Innovation Programme Horizon 2020, aims at developing a novel 2-stroke SI engine, weighting less than 50 kg and delivering 100 kW@5500 rpm, along with a brake specific consumption lower than 240 g/kWh in all the most relevant operating conditions.The core of the project is the scavenging system, without poppet valves and adopting a low pressure direct injection in combination with direct high pressure injection, and the combustion system. This paper is focused on the injection optimization; thanks to the CFD 3D simulations several possibilities are analysed in order to obtain a fuel trapping ratio that is more than 95% at maximum engine speed, high air-fuel mixing and an overall stoichiometric mixture. The optimization main parameters include number of injectors, geometrical relative position, injection timing and injected fuel mass division

Notes:

Vendor supplied data

Publisher Number:

2021-01-1179

Access Restriction:

Restricted for use by site license