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. The work to date on a prototype injector concentrated on imaging of the fuel spray and combustion in a high-speed optical engine, and emissions and fuel consumption in a functionally identical single-cylinder thermodynamic engine. The performance and emissions measurements included PM, CO and THC emissions combined with IMEP, COV of IMEP and ISFC. The results confirmed performance superior to PFI, and even exceeded some typical GDI characteristics.