Abstract
The serious problem of gasoline engines is low thermal efficiency. If the compression ratio is raised for thermal efficiency improvement, knocking occurs. By making piston-movement faster near TDC, it was shown that anti knock ability was enhanced and heat loss decreased. However, it turned out that volumetric efficiency deteriorates. To improve the volumetric efficiency, numerical simulation was carried out in this study by making 1D and 3D simulations with varying the intake valve timing.
Keywords:Knocking, Volumetric efficiency, Piston-crank mechanism, Compression ratio, Valve timing