Optimization of Exhaust-Pipe Tuning on a 4-Stroke Engine Using Simulation

Engine performance simulation software has become an integral part of the engine designer's toolkit. However, optimization of a particular design using such software is often difficult and time consuming. This is due primarily to the number of parameters required to adequately characterize the engine and the interdependency of these parameters on one another. This paper reports on the use of optimization algorithms embedded within the simulation software package, VIRTUAL 4-STROKE™ (1) ¹, that help to automate the engine design process and shorten the development time to meet specific performance goals.

A previous paper by Blair et al (2), presented to the society at SETC 2001, demonstrated the ability to predict the behavior of tuned exhaust systems on a single cylinder 4-stroke motorcycle engine using VIRTUAL 4-STROKE. These engine and pipe arrangements are now optimized using simulation to achieve several different performance goals including maximum power and torque over both wide and narrow engine speed ranges. A fast, accurate and robust optimization strategy is presented. The benefit of such technology as a valuable and efficient design tool is demonstrated.

Experimental validation of the simulation was conducted on an engine dynamometer. Comparison with measured brake data for each optimized design is presented.