A Numerical Method for Noise Optimization of Engine Structures

Abstract

A numerical procedure is described for optimizing finite element models of engine structures for minimum noise radiation. A statistical technique is used to select sample points in a multi-dimensional design variable space from which an approximating response surface is derived. Optimization of this analytic model is then carried out interactively with variable bounds and constraints as required to meet design objectives. The underlying noise analysis calculation uses a modal analysis algorithm to determine the surface vibration velocity and hence the radiated sound power. It incorporates a sophisticated procedure to determine the forces applied by the crank train to the cylinder block and head. Although computationally intensive, useful design studies are now practical using concept level finite element models.