Ultra Boost for Economy: Extending the Limits of Extreme Engine Downsizing

Abstract

The paper discusses the concept, design and final results from the 'Ultra Boost for Economy' collaborative project, which was part-funded by the Technology Strategy Board, the UK's innovation agency. The project comprised industry-and academiawide expertise to demonstrate that it is possible to reduce engine capacity by 60% and still achieve the torque curve of a modern, large-capacity naturally-aspirated engine, while encompassing the attributes necessary to employ such a concept in premium vehicles.In addition to achieving the torque curve of the Jaguar Land Rover naturally-aspirated 5.0 litre V8 engine (which included generating 25 bar BMEP at 1000 rpm), the main project target was to show that such a downsized engine could, in itself, provide a major proportion of a route towards a 35% reduction in vehicle tailpipe CO 2 on the New European Drive Cycle, together with some vehicle-based modifications and the assumption of stop-start technology being used instead of hybridization. In order to do this vehicle modelling was employed to set part-load operating points representative of a target vehicle and to provide weighting factors for those points. The engine was sized by using the fuel consumption improvement targets and a series of specification steps designed to ensure that the required full-load performance and driveability could be achieved.The engine was designed in parallel with 1-D modelling which helped to combine the various technology packages of the project, including the specification of an advanced charging system and the provision of the necessary variability in the valvetrain system. An advanced intake port was designed in order to ensure the necessary flow rate and the charge motion to provide fuel mixing and help suppress knock, and was subjected to a full transient CFD analysis. A new engine management system was provided which necessarily had to be capable of controlling many functions, including a supercharger engagement clutch and full bypass system, direct injection system, port-fuel injection system, separately-switchable cam profiles for the intake and exhaust valves and wide-range fast-acting camshaft phasing devices.

Observations on and potential trends for mechanically supercharging a downsized passenger car engine:a review

“…a reduction in the turbocharger inertia) and correct charging system matching, with the requirement of further downsizing to achieve a superior fuel efficiency 10 to satisfy the increasingly strict fuel consumption regulations, supercharging technology may have to be introduced to increase the low-end torque and to improve the transient performance when needed.…”

Effect of Fuel Injection Strategy on the Carbonaceous Structure Formation and Nanoparticle Emission in a DISI Engine Fuelled with Butanol

“…These datasets suggest that advanced fuel delivery is not beneficial for lowering particulate emissions; this is most important, especially as when increasing load (and therefore high fuel flow is present), injection needs to be advanced so that high intake air velocity is exploited. To put things into perspective, injection duration was around 40 CAD (lower for gasoline, higher for the alcohol); when considering that the investigated load level is WOT, for boosted conditions fuel flow can range from 1.5 to 2.5 times, depending on the level of downsizing [50]. Therefore, changes in injection phasing required by high load conditions can have significant effects, even for modifications such as the relatively narrow 40 CAD shift that was considered for this study.…”

Targeted energy transfer and modal energy redistribution in automotive drivetrains

“…Recent developments have resulted in downsized turbocharged engines replacing the large capacity naturally aspirated variety [1]. Higher output power-toweight ratio is the trend in modern powertrain engineering [2][3][4].…”