Simulation of torsional dynamics of a two-cylinder internal-combustion engine connected to a dynamometer

Abstract

Internal-combustion engines with a small number of cylinders can be difficult to test on a dynamometer due to the increased load of parts of the torsional chain between the engine and the dynamometer. This is due to the uneven rotation of the crankshaft, especially at low speeds. It is therefore advisable to perform appropriate simulations before the experiment itself. The paper describes a time-efficient simulation of the torsional dynamics of a two-cylinder engine for an electric vehicle range extender, connected via a complex torsional chain to an electric dynamometer for testing purposes. The simulations are performed in the frequency domain by means of an in-house software built in the Fortran programming language. Particular attention is paid to the disc clutch, which is significantly loaded in the case of this engine.