APPLICATION OF NUMERICAL MODELLING METHODS TO THE DESIGN OF SILENCERS

APPLICATION OF NUMERICAL MODELLING METHODS
TO THE DESIGN OF SILENCERS
E Quaranta ISVR Consulting. University of Southampton. SO17 1BJ. UK S Roberts ISVR Consulting, University of Southampton, SO17 1BJ. UK
1 INTRODUCTION
Many machines and industrial production facilities require silencers to reduce the noise transmission through intake or exhaust ducts. with examples ranging through motor car exhausts, industrial silencers and aeroengine intake and exhaust liners. Traditional silencer design methods use analytical or transmission matrix acoustic models. followed by empirical development work to produce robust designs. However. these methods are not suitable for designing silencers with unusual chamber shapes and layouts and are generally not accurate enough to predict
backpressure. which may be an important design constraint.
Numerical modelling methods developed for aeroacoustics problems are now well established for application to a wide range of engineering problems. After a brief introduction to the main types of silencers, this paper summarises traditional analytical methods versus modern numerical modelling and illustrates the computational process applied to three case studies