A Review of Experimental and Simulation Studies on Controlled Auto-Ignition Combustion

Influence of the Variable Valve Timing Strategy on the Control of a Homogeneous Charge Compression (HCCI) Engine

“…Different methods that have the potential to control the start of auto ignition and the heat release rate of the HCCI combustion, together with their effectiveness and practical feasibility, have been discussed in [7]. Trapping the hot residual gases (RG) into the cylinder, accomplished by fully variable valve timing (FVVT) system, appears to be the most promising and the most feasible way for achieving the HCCI combustion control in the certain load range [8] 2 .…”

“…Additional test with unsymmetrical valve timings and at other engine speeds (1000 rpm, 3000 rpm, 7 The amount of trapped exhaust gas is an instantaneous value. 4000rpm and 5000rpm) are underway, and the data obtained from those tests will be used to re-validate the model and results will be published elsewhere.…”

Enlarging the Operational Range of a Gasoline HCCI Engine By Controlling the Coolant Temperature

“…The fuel consumption (ISFC) deteriorates with a higher coolant temperature (Fig. 13) 4 . This is an inevitable 4 The ISFC obtained for Tcoolant=125 0 C is however, still proportionally lower compared to that obtained when the engine operated in SI mode (∼ 20%) at given load [7].…”

“…By varying the amount of TRG in the fresh air/fuel mixture (inside the cylinder), the charge mixture temperature and composition can be controlled and hence, the auto ignition timing and heat release rate [4].…”

A CFD Model with Optical Validation on In-cylinder Charge Performances of CAI Engines

“…Several potential control methods have been investigated worldwide to provide the compensation required for changes in engine speed and load [7]. One promising option is realized by varying the amount of hot residuals trapped inside the cylinder, or named as internal exhaust gas recirculation (IEGR), mixed into the incoming fresh charge using a Fully Variable Valve Timing (FVVT) system, as shown in Figure 1.…”