Acoustic Analysis and Design of Short Elliptical End-Chamber Mufflers (SpringerBriefs in Applied Sciences and Technology)

Foreword
Preface
Acknowledgements
Contents
About the Author
1 Introduction
	1.1 Elliptical Mufflers for Automotive Exhaust Application: Motivation
	1.2 State of the Art and Scope
		1.2.1 Book Outline
	References
2 Acoustic Wave Propagation in an Elliptical Cylindrical Waveguide
	2.1 Introduction: A Brief Review on Mathieu Functions and Objectives
	2.2 The Convective 3-D Helmholtz Equation in Elliptical Cylindrical Co-ordinates
	2.3 Solution of Wave Equation in Angular and Radial Co-ordinates
		2.3.1 Computation of Mathieu Functions
		2.3.2 Computation of Modified Mathieu Functions
	2.4 Acoustic Pressure Field in a Rigid-Wall Elliptical Cylindrical Waveguide
	2.5 Numerical Computation of the q Parameters
	2.6 Tabulation of Parametric Zeros and Non-Dimensional Resonance Frequencies
	2.7 Resonance Frequency Variation with Aspect-Ratio, Interpolating Polynomials and Mode Shapes
		2.7.1 Circumferential Modes of Even and Odd Type
		2.7.2 Radial Modes and Cross-Modes of Even and Odd Type
	2.8 Family of Ellipses Having Equal Cross-Sectional Area
	Appendix: Resonance Frequencies of a Clamped Elliptical Membrane
	References
3 Characterization of an Elliptical Chamber Muffler
	3.1 Three-Dimensional Green’s Function
	3.2 Acoustic Pressure Response Based upon the Uniform Piston-Driven Model
		3.2.1 Excitation at an End Port
		3.2.2 Homogeneous Wave Equation Subject to Inhomogeneous Conditions
		3.2.3 Excitation at a Side Port
	3.3 Integration of Green’s Function Over the Piston Area Due to End or Side Port
		3.3.1 End Port
		3.3.2 Side Port
	3.4 Influence of Location of End and Side Ports on the Propagation of Even and Odd Modes
	3.5 Evaluation of the Impedance [ Z ] Matrix Parameters
		3.5.1 End-Inlet and End-Outlet Muffler
		3.5.2 End-Inlet and Side-Outlet Configuration
	3.6 Computation of Transmission Loss Performance in Terms of [ Z ] Matrix Parameters
		3.6.1 Analysis/Prediction of the Observed Peaks and Troughs in the TL Spectrum
	References
4 Double-Tuned Short End-Chamber Mufflers
	4.1 Multi-pass Perforated Duct Muffler System
		4.1.1 Short End-Chambers: Integral Component of a Multi-pass Perforated Muffler
	4.2 End-Inlet and End-Outlet Configurations
		4.2.1 Inlet on the Major-Axis and Outlet on the Minor-Axis: Optimal Port Location
		4.2.2 Inlet on the Major-Axis and Outlet Port Centered
		4.2.3 Inlet Port Centered and Outlet Located on the Minor-Axis
		4.2.4 Ports Offset at Equal Distances on the Major-Axis or Minor-Axis: Non-tuned Configuration
	4.3 End-Inlet and Side-Outlet Configurations
	4.4 Design Guidelines
	References
5 Summary of Contribution and Directions for Future Work
	5.1 Contribution
	5.2 Future Investigation: Analysis and Design of Perforated Elliptical Mufflers for Industrial and Automotive Applications
	References
Index