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Technical Paper

µMist® - The next generation fuel injection system: Improved atomisation and combustion for port-fuel-injected engines

The Swedish Biomimetics 3000's μMist® platform technology has been used to develop a radically new injection system. This prototype system, developed and characterized with support from Lotus, as part of Swedish Biomimetics 3000®'s V₂IO innovation accelerating model, delivers improved combustion efficiency through achieving exceptionally small droplets, at fuel rail pressures far less than conventional GDI systems and as low as PFI systems. The system gives the opportunity to prepare and deliver all of the fuel load for the engine while the intake valves are open and after the exhaust valves have closed, thereby offering the potential to use advanced charge scavenging techniques in PFI engines which have hitherto been restricted to direct-injection engines, and at a lower system cost than a GDI injection system.
Technical Paper

Improving Fuel Economy in a Turbocharged DISI Engine Already Employing Integrated Exhaust Manifold Technology and Variable Valve Timing

Many new technologies are being developed to improve the fuel consumption of gasoline engines, including the combination of direct fuel injection with turbocharging in a so-called ‘downsizing’ approach. In such spark ignition engines operating on the Otto cycle, downsizing targets a shift in the operating map such that the engine is dethrottled to a greater extent during normal operation, thus reducing pumping losses and improving fuel consumption. However, even with direct injection, the need for turbine protection fuelling at high load in turbocharged engines - which is important for customer usage on faster European highways such as German Autobahns - brings a fuel consumption penalty over a naturally-aspirated engine in this mode of operation.
Technical Paper

Optimal Control Inputs for Fuel Economy and Emissions of a Series Hybrid Electric Vehicle

Hybrid electric vehicles offer significant fuel economy benefits, because battery and fuel can be used as complementing energy sources. This paper presents the use of dynamic programming to find the optimal blend of power sources, leading to the lowest fuel consumption and the lowest level of harmful emissions. It is found that the optimal engine behavior differs substantially to an on-line adaptive control system previously designed for the Lotus Evora 414E. When analyzing the trade-off between emission and fuel consumption, CO and HC emissions show a traditional Pareto curve, whereas NOx emissions show a near linear relationship with a high penalty. These global optimization results are not directly applicable for online control, but they can guide the design of a more efficient hybrid control system.
Technical Paper

Flex-Fuel Vehicle Development to Promote Synthetic Alcohols as the Basis of a Potential Negative-CO2 Energy Economy

The engine of a high performance sports car has been converted to operation on E85, a high alcohol-blend fuel containing nominally 85% ethanol and 15% gasoline by volume. In addition to improving performance, the conversion resulted in significant improvement in full-load thermal efficiency versus operation on gasoline. This engine has been fitted in a test vehicle and made flex-fuel capable, a process which resulted in significant improvements in both vehicle performance and tailpipe CO2 when operating solely on ethanol blends, offering an environmentally-friendly approach to high performance motoring. The present paper describes some of the highlights of the development of the flex-fuel calibration to enable the demonstrator vehicle to operate on any mixture of 95 RON gasoline and E85 in the fuel tank. It also discusses how through detailed development, the vehicle has been made to comply with primary pollutant emissions legislation on any ethanol-gasoline mixture up to E85.
Technical Paper

The HOTFIRE Homogeneous GDI and Fully Variable Valve Train Project - An Initial Report

There is a great deal of interest in new technologies to assist in reducing the CO2 output of passenger vehicles, as part of the drive to meet the limits agreed by the EU and the European Automobile Manufacturer's Association ACEA, itself a result of the Kyoto Protocol. For the internal combustion engine, the most promising of these include gasoline direct injection, downsizing and fully variable valve trains. While new types of spray-guided gasoline direct injection (GDI) combustion systems are finally set to yield the level of fuel consumption improvement which was originally promised for the so-called ‘first generation’ wall- and air-guided types of GDI, injectors for spray-guided combustion systems are not yet in production to help justify the added complication and cost of the NOx trap necessary with a stratified combustion concept.
Technical Paper

Production Electro-Hydraulic Variable Valve-Train for a New Generation of I.C. Engines

Recently [SAE 2001-01-0251], we reported for the first time on using a fully variable valve train (FVVT) to facilitate controlled auto-ignition (CAI) in 4-stroke gasoline engines, with a 23% reduction in fuel consumption and a reduction of up to 95% in emission levels. In this paper we look at the industry trends towards increased control over combustion related processes occurring in modern engines, which signaled the direction towards the CAI work, and review a range of valve train technologies available to meet these trends. Previous key work conducted by industry and academic researchers is also reviewed to establish a minimum specification requirement for the new fully variable valve train systems. The paper then describes two electro-hydraulic valve actuation systems capable of meeting these specifications, the first a research grade system used on single cylinder engines and the second a new production viable system that is aimed at bringing FVVT's to high volume production.
Technical Paper

Fuel Economy Improvement Using Combined CAI and Cylinder Deactivation (CDA) - An Initial Study

Ever increasing oil prices and emissions legislation have forced automobile manufacturers to investigate new methods and technologies to reduce fuel consumption in Spark Ignition (SI) engines. Two such technologies are Controlled Auto Ignition (CAI) and Cylinder Deactivation (CDA), both of which have the potential to decrease fuel consumption at light load. This paper presents synergies between running engines in CAI and CDA operation. A baseline simulation model of a production intent vehicle incorporating a four-cylinder engine was produced and correlated to measured test data. Experimental results of various CAI and CDA investigations have been projected onto the baseline simulation model and an analysis performed over the New European Drive Cycle (NEDC). It has been found that running an engine in CAI or CDA mode improves efficiency in explicit areas of the fuel map.
Technical Paper

Variable Valve Actuated Controlled Auto-Ignition: Speed Load Maps and Strategic Regimes of Operation

This paper outlines a vision of future engine requirements and operating strategies to reduce fuel consumption and engine out emissions. It discusses in detail the valve operating strategies used to achieve throttleless spark ignition (SI) load control and two methods of controlled Auto Ignition (AI). Emission and fuel consumption speed load maps are shown and differences between SI and AI maps are discussed. Many fully variable valve-timing strategies are proposed and conclusions are reached that clearly indicate significant improvements in IC engine performance are still achievable.
Journal Article

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

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 academia-wide 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 CO2 on the New European Drive Cycle, together with some vehicle-based modifications and the assumption of stop-start technology being used instead of hybridization.