Lotus Engineering is celebrating its latest accolade after triumphing at ‚â€˜The Engineer Technology +
Innovation Awards 2008‚â€™ with another environmentally focused project. The winning project, Project HOTFIRE, developed a gasoline direct injection (GDI) engine concept
that reduces fuel consumption by 15% and was named the leading academic collaborative project in the automotive sector.
Project HOTFIRE was made up of a collaboration of engine specialists from Lotus Engineering, Continental Powertrain, University College London (UCL) and Loughborough University, with funding from EPSRC (Engineering and Physical Sciences Research Council). The project studied the potential efficiency gains of spraying fuel directly into the cylinders of a petrol-driven engine, rather than introducing a fuel/air mixture. Due to outstanding early results, the project progressed further with the delivery of a concept-car engine which has been the subject of interest from a number of large manufacturers.
Two single cylinder research engines were designed and constructed by Lotus
Engineering, one of which was optically accessed. The in-cylinder geometry of
the two engines was identical and features a close spaced direct injection
system with a centrally-mounted injector architecture.
The optical version of the engine incorporated a full length fused silica quartz
cylinder liner with a full view of the pent roof of the combustion chamber and a
sapphire window in the piston crown. This allowed an advanced suite of laser
diagnostics to measure air motion, injection characteristics, air/fuel mixing and
combustion. This engine was based at Loughborough University for detailed
studies of these in-cylinder phenomena.
The second engine was placed at UCL, and was updated to the same engine architecture as the optical engine, to measure emissions and fuel economy.
The principle of the investigation was to use early inlet valve closing as a
means of controlling the load on the engines, with a minimum amount of
throttle, and so gain significant fuel savings. The emission measurements
were essential, as any fuel savings could not be at the expense of the exhaust
emissions from the engine.
The end application of this project is a direct injection spark ignition engine
architecture that does not require stratified lean burn combustion to achieve
significant, fuel economy savings of approximately 15%. This ensures that the
system can be used over all speed/load ranges and eliminates the need for an
expensive lean NOx trap which is usually required when lean combustion is
Early results from this project were so successful that the same architecture
was adopted for the Low CO2 project, a collaboration between Lotus
Engineering and Continental Powertrain with funding from the Energy Saving Trust (EST). This Low COd project has successfully delivered a 3-cylinder mild-hybrid engine incorporating the cylinder head design used by the research and this engine has been installed in Opel Astra demonstrator vehicles which demonstrate significant improvements in both performance and CO2 emissions.
Filed Under: Automotive, Green engineering