High speed injector flow and temperature measurements for engine fuel injection systems

Lead Research Organisation: University of Oxford
Department Name: Engineering Science

Abstract

The European Road Transport Research Advisory Council forecast that hybridized internal combustion engine (ICE) vehicles will account for approximately 50% of the total road transport energy usage in the year 2050 (Report from ERTRAC CO2 Integrated Approach - www.ertrac.org/2017conference. This significant energy usage from a relatively small fraction of the total fleet, which is expected to be 80% electrified, is due to the ICEs projected end use in high mileage and specialised applications such as agriculture and construction for which no viable alternative has been proposed. It is therefore essential that ICE research and development is maintained, and that it is focussed on technological measures to simultaneously increase fuel economy and reduce legislated exhaust emissions.

Modern ICEs routinely employ high-pressure fuel injection systems and complex and varied fuel injection strategies, often with multiple injection events (up to twelve individual injections) pre cycle, to increase efficiency and reduce emissions. Herein lies a significant problem. For maximum benefit, these advanced fuel injection strategies should be applied to the engine on a cycle-by-cycle, cylinder-by-cylinder basis, and each 'packet' of injected fuel should be precisely metered and timed. However, currently it is not possible to measure the fuel flow rate in an individual injection event - either in real time or on an engine. The lack of measurement capability in this area represents a significant barrier to the development and realisation of ultra efficient, ultra low emission engines.

This project falls within the EPSRC Energy research area.

The primary objectives of the work are:
1. The design and build of flow tubes with >1 kHz resonant frequency
2. The development of a prototype meter for gasoline fuel injection systems (300 bar maximum working pressure)
3. The deployment of the new technology on a gasoline engine, thereby demonstrating that on-engine injector flow measurements are possible in real time
4. The development of a prototype meter suitable for diesel common rail systems (necessitating a significant increase in working pressure - 3000 bar target) and the on-engine demonstration of the device

This project will develop new instrumentation technology (the Fast Next Generation Coriolis or Fast NGC) that would enable the fuel injection rate (FIR) to be obtained for an individual injector, from an engine, in real time. This is a challenging and wholly novel application for Coriolis flow meters and such measurements would be a world's first. The project is based on new, patented signal processing tools recently developed at Oxford that provide a step change in the dynamic response of the Coriolis meter, and on the results of a recent, successful, feasibility study (http://www.eng.ox.ac.uk/engines/research/fast-coriolis-meters-for-real-time-on-engine-measurement-of-fuel-injector-flow). This project will expand the research of the feasibility study to deliver a world-leading laboratory instrument with the precise measurement capability that is demanded by the automotive research community to facilitate significant advances in low emission engines.

The direct beneficiaries of this research includes the academic community as described in the previous section of this form, the automotive industry (in particular, the project's partners and the UK's fuel and engine manufacturers who would have the opportunity to build competitive advantage through early access to the developed instrument and the generated data), and wider industry where faster, more accurate flow measurements are required. Significant indirect beneficiaries of the research include urban populations and public health services.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/R512333/1 01/10/2017 30/09/2021
1939160 Studentship EP/R512333/1 01/10/2017 30/09/2021 Maruthi Malladi