Abstract
The internal combustion engines for future automotive propulsion, with a high specific torque in a wide speed range, have to accomplish drastic norms regarding CO2 emissions – thus fuel consumption – and pollutant emission. A compact basic direct injection engine with joinable super- and turbocharging is for both SI and CI engines families the most promising solution. The effectiveness of such configuration is mainly determined by the management of scavenging – with the target of the optimum ratio between fresh air and burned gas within the cylinder in the whole load and speed range.
The paper presents the potential of a new concept of valve control by concentric cams, in base on 1D/3D simulation of the scavenging, internal mixture formation by direct injection, combustion and formation of exhaust gas components. The models are calibrated by experimental analysis on engine test benches.
The influence of the intake and exhaust valve control in terms of phasing, valve lift and opening duration on engine performance is illustrated for different load/speed combinations.