Torsional vibration moment analysis of a three-cylinder internal combustion engine

Abstract

In this study, a combined dynamic and thermodynamic model of a three-cylinder diesel engine has been developed and moments causing torsional vibration of the engine body have been estimated. The model involves motion equations of pistons, connecting rods and crankshaft as well as thermodynamic relations. The heat generation required for the thermodynamic cycle was provided by an algebraic equation established via the Gaussian function. The heat equation was optimised so as to avoid diesel knocking and formation of harmful emissions. The minimisations of pitch and yaw moments were examined via adding counterweights onto the crankshaft. The yaw moment was found to be totally eliminable but the pitch moment was not. According to a coordinate system whose origin is at the mass centre of the engine and its z axis is co-directional with cylinder axes, the flexible mounting elements of the engine were found to be able to set at somewhere on x and y axes.