Zur numerischen Simulation des Ladungswechsels im Verbrennungsmotor

Abstract

The gas exchange in the cylinders is essential for the overall performance of an internal combustion engine. A CAE approach leads to technically improved and less polluting engines. Its base is a network formulation of the engine. The mathematical modell describes the gas flow in the various parts of the engine. A system of ordinary differential equations in time represents conservation of mass and energy in the cylinder. For the cylinder and its connections a semi-empirical approach is used. Considering the gas flow in pipes yields an hyperbolic system of partial differential equations, the unsteady one-dimensional Euler equations. In contrast to classical difference schemes the numerical treatment with an ENO scheme prevents spurious numerical oscillations. The implementation of the new scheme in an industrial simulation package shows that even large-scale problems can be solved without needing more cpu-time in comparision with the same relative error.