Design and Evaluation of the ELEVATE Two-stroke Automotive Engine

Abstract

ELEVATE (European Low Emission V4 Automotive Two-stroke Engine) was a research project part funded by the European Commission to design and develop a compact and efficient gasoline two-stroke automotive engine. Five partners were involved in the project, IFP (Institut Francais Du Parole) who were the project leaders, Lotus, Opcon (Autorotor and SEM), Politecnico di Milano and Queen's University Belfast. The general project targets were to achieve Euro 3 emissions compliance without DeNOx catalisation, and a power output of 120 kW at 5000 rev/min with maximum torque of 250 Nm at 2000 rev/min. Specific targets were a 15% reduction in fuel consumption compared to its four-stroke counterpart and a size and weight advantage over the four-stroke diesel with significant reduction in particulate and NOx emissions. This paper describes the design philosophy of the engine as well as the application of the various partner technologies used. Incorporated in the design was an air assisted direct fuel injection system, IAPAC, (Injection Assistee Par Air Comprime) and a charge trapping valve system in the exhaust port. A dual delivery screw compressor for external scavenging supplied a high volume of low-pressure charge air and a low volume of higher-pressure air for the fuel injection system. A high-energy flexible ignition system was used and, at part load, a Controlled Auto Ignition (CAI) process was developed. Lessons learnt from the project, both advantages and associated problems, will be discussed, as well as results from testing. The actual engine tested was constrained by the financial and time limitations of a research funded project. A production version of the engine was partially designed using 3D CATIA. This will be shown and discussed also.