A Hybrid approach for aeroacoustic analysis of the engine exhaust system

Sathyanarayana, Y and Munjal, ML (2000) A Hybrid approach for aeroacoustic analysis of the engine exhaust system. In: Applied Acoustics, 60 (4). pp. 425-450.

Preview

PDF hybrid_approach-appacou.pdf Download (524kB)

Abstract

This paper presents a new hybrid approach for prediction of noise radiation from engine exhaust systems. It couples the time domain analysis of the engine and the frequency domain analysis of the muffler, and has the advantages of both. In this approach, cylinder/cavity is analyzed in the time domain to calculate the exhaust mass flux history at the exhaust valve by means of the method of characteristics, avoiding the tedious procedure of interpolation at every mesh point and solving a number of equations simultaneously at every junction. This is done by making use of an interrelationship between progressive wave variables of the linear acoustic theory and those of the method of characteristics. In this approach, nonlinear propagation in the exhaust pipe is neglected and free expansion is assumed at the radiation end of the exhaust pipe. In the case of a muffler proper, expansion from the exhaust pipe into the first chamber is assumed to be a free expansion. Various results of this approach are compared with those of the method of characteristics and the classical acoustic theory, and various peaks and troughs in insertion loss curves are analytically validated.

Item Type:	Journal Article
Publication:	Applied Acoustics
Publisher:	Elsevier Science Ltd
Additional Information:	The cpoyright of this article belongs to Elsevier Science Ltd
Keywords:	Engines;Mufflers;Aeroacoustics;Method of characteristics;Hybrid approach
Department/Centre:	Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	16 Aug 2004
Last Modified:	29 Sep 2010 08:50
URI:	http://eprints.iisc.ac.in/id/eprint/1270

Actions (login required)

View Item