The Potential of Enhanced HCCI / CAI Control Through the Application of Spray Guided Direct Injection

The role of charge stratification for reducing ringing in gasoline engine homogeneous charge compression ignition combustion investigated by optical imaging

“…On the other hand, a late direct injection of gasoline (with single-stage ignition) under stoichiometric conditions could be used to increase the load substantially (from 350 to 700 kPa IMEP net ), 9 although this was with substantially later combustion phasing and it is unclear what the results would have been if they had allowed the combustion to be as late in the homogeneous case (they used fixed NVO camshaft timings). In another study, it is shown that in an engine operating on gasoline with NVO at λ = 1.56, charge stratification can effectively reduce the pressure rise rates if the stratification is sufficient to create fuel-rich zones; otherwise, it increases the pressure rise rate.…”

Numerical Modelling and Optimization of the Mixture Formation Processby Multi-Hole Injectors in a GDI Engine

“…This technology is today still applied, because it offers an additional degree of freedom constituted by the direct injection of air, that allows a more effective control of local oxygen concentration, temperature and charge motion through the cycle [Shim et al, 2008]. Alternative solutions, better meeting the requirements for the development of more efficient GDI engines, are the high pressure injectors: the swirl type injector generates an hollow-cone fuel spray by providing a swirl rotational motion to the fuel, that widely disperses and well-atomizes the spray at moderate injection pressures [Brewster et al, 2008]; the multi-hole configuration, on the other hand, exhibits flexible spray patterns that reduce the fuel impingement on the cylinder walls and improve the spray stability (cone shape) with respect to the existing backpressure. Three commercial multi-hole injectors suitable to be mounted on high-performances SI engines are tested within the present work.…”