The Dynamics of the Otto Engine

Abstract

The dynamic calculation of a certain mechanism and of the piston crankshaft mechanism, used as the main mechanism for Otto internal combustion engines, also implies the influence of external forces on the actual, dynamic kinematics of the mechanism. Take into account the strong and inertial engine forces. Sometimes weight forces can also be taken into account, but their influence is even smaller, negligible even in relation to inertial forces that are far higher than gravitational forces. In the present paper, one carry out an original method of determining the dynamics of a mechanism, applying to the main mechanism of an Otto or diesel engine. The presented method of work is original and complete. Relationships (1) express the velocity of the center of gravity to calculate the moment of inertia (mechanical or mass, of the whole mechanism) reduced to the crank (2). In dynamic calculations, the first derivative of the reduced mechanical inertia moment, derived by the angle FI (relations 3-4), is also required. For dynamic calculation, it is also necessary to determine the expression of the total torque momentum and crank-resistance forces (relations 5-6). The differential equation of the machine (7) is arranged under the more convenient forms (8) to solve it. It is easily observed that a second-degree equation has been reached, which is solved by the known formula (9).