A unified method for calculating engine flows

In recent years, Multidimensional Models (MDMs) have been developed for calculating the flow and other processes in engine cylinders and combustion chambers. Some of the recent progress is described in reference (1). The present contribution focusses on one particular aspect of MDMs, namely that of geometric flexibility and describes a method developed specifically for performing flow calculations in a wide range of engine types. Use of the method is illustrated by examples which demonstrate various applications. These include: (a) the compression-induced flow structure in the piston bowl of a direct-injection diesel engine using both on and off-axis combustion chambers; (b) comparison with experimental data of the flow in a non-compressing model engine and (c) the 3-dimensional flow in a uniflow-scavenged two-stroke. The paper concludes by indicating possible future developments in this area of multidimensional modelling.