The Application of Design of Experiments and 1-D Simulation to Create a Rapid Concept Optimisation Tool for I4 Engines

This paper describes a method for the rapid generation of a first estimate of engine tuning parameters for a 4-cylinder naturally aspirated spark ignition engine. These parameters involve the primary lengths and diameters of the intake and exhaust systems. These variables were optimised for peak power over a range of different speeds and for different engine capacities.

A 4-cylinder engine was modelled in GT-Power, a one-dimensional engine cycle simulation package. All the above variables were included in the model and a number of assumptions made about the base engine design for each optimisation point. A range of values for all the variables were analysed within a DOE matrix. The resulting response surfaces can be used to give approximate tuning dimensions to provide a starting point for packaging studies and more detailed simulations immediately on commencing a new project.