Optimization of the charge motion and related intake ports design by 3D CFD to implement the SwumbleTM-like charge motion in the cylinder is achieved!
The first step of the optimization of the engine combustion system was performed by our partner IFPEN through 3D CFD simulations to implement the Swumble™ Concept. Swumble™ is an innovative charge motion concept to produce high Turbulence Kinetic Energy (TKE) at Top Dead Centre, especially when coupled with early or late intake valves closing actuation (EIVC / LIVC), in order to enhance the combustion propagation in these highly diluted conditions. Thanks to the innovative Swumble™ fluid motion, the turbulent kinetic energy required for sustaining ignition and flame propagation in diluted conditions is significantly increased.
The optimization variables used are the cylinder head (to increase the combustion chamber volume under the spark plug, adjustment of the intake valve mask to influence the internal charge motion), the piston design (increase the CR target) and the modification of the intake port and of the valve seat (to increase the turbulence level generated in the cylinder).
A geometry with a compression ratio of 13.6 leading to an increased turbulence level for two different intake valve lifts (Atkinson and Miller) was obtained. This relative increase in turbulence by about 40% will contribute to a reduction in the combustion duration, thereby increasing the engine efficiency. In addition, by optimising the flow movement, better air-fuel mixing is expected for both petrol and the various alcohol-based biofuels.
The increases obtained In TKE @ 690 [cad] are in average +40% to +60% for EIVC and for LIVC (see below)!
Task contact: Paul Luca email: paul-georgian.luca@ifpen.fr