Table Of ContentIUTAM Symposium on Designing for Quietness
SOLID MECHANICS AND ITS APPLICATIONS
Volume 102
Series Editor: G.M.L. GLADWELL
Department of Civil Engineering
University (il Waterloo
Waterloo, Ontario, Canada N2L 3GI
Aims and Scope of the Series
The fundamental questions arising in mechanics are: Why?, How?, and How much'!
The aim of this series is to provide lucid accounts written by authoritative researchers
giving vision and insight in answering these questions on the subject of mechanics as it
relatcs to solids.
The scope of the series covers the entire spectrum of solid mechanics. Thus it includes
the foundation of mechanics; variational formulations; computational mechanics;
statics, kinematics and dynamics of rigid and elastic bodies: vibrations of solids and
structures; dynamical systems and chaos; the theories of elasticity, plasticity and
viscoelasticity; composite materials; rods, beams, shells and membranes; structural
control and stability; soils, rocks and geomechanics; fracture; tribology; experimental
mechanics; biomechanics and machine design.
The median level of presentation is the first year graduate student. Some texts are mono
graphs defining the current state of the field; others are accessible to final year under
graduates; but essentially the emphasis is on readability and clarity.
For a list (~l related mechanics titles, see/inal pages.
IUTAM Symposium on
Designing for Quietness
Proceedings of the IUTAM Symposium held in Bangalore,
India, 12-14 December 2000
Edited by
M.L. MUNJAL
Facility for Research in Technical Acoustics (FRITA).
Department of Mechanical Engineering.
Indian Institute of Science,
Bangalore. India
Springer-Science+Business Media, B.V.
A C.LP. Catalogue record for this book is available from the Library of Congress.
Printed on acid~lree paper
All Rights Reserved
ISBN 978-90-481-6081-5 ISBN 978-94-017-0095-5 (eBook)
DOI 10.1007/978-94-017-0095-5
© 2002 Springer Science+Business Media Dordrecht
Originally published by KIuwer Academic Publishers in 2002.
Softcover reprint ofthe hardcover 1s t edition 2002
No part of this work may be reproduced, stored in a retrieval system, or transmitted
in any form or by any means, electronic, mechanical, photocopying, microfilming, recording
or otherwise, without written permission from the Publisher, with the exception
of any material supplied specifically for the purpose of being entered
and executed on a computer system, for exclusive use by the purchaser of the work.
Contents
Preface xiii
Contributing Authors xv
ANALYSIS AND DESIGN OF AN ANNULAR AIRGAP LINED DUCT
FOR HOT EXHAUST SYSTEMS 1
M. L. MUNJAL and B. VENKATESHAM
l. Introduction 1
2. The Governing Equations 3
3. Solution of the Governing Equations 6
4. Derivation of the Transfer Matrix 8
5. Validation 9
6. Parametric Studies 12
7. Concluding Remarks 16
References 19
ACOUSTICAL MATERIALS FOR AUTOMOTIVE NVH REDUCTION 21
A.R.MOHANTY
l. Introduction 21
2. Sound Absorption Co-efficient 22
3. Transmission Loss 23
4. Results 25
5. Conclusions 28
References 31
ACOUSTIC CHARACTERIZATION OF ONE-PORT SOURCES AND
ITS APLICATION TO DUCT NOISE CONTROL SYSTEM DESIGN 33
M. G. PRASAD
l. Introduction 33
2. System Model 33
3. Source Characteristics 36
v
VI IUTAM SYMPOSIUM ON DESIGNING FOR QUIETNESS
4. Direct Methods 36
5. Indirect Methods 38
6. System Performance 40
7. Concluding Remarks 44
References 45
THEORETICAL AND EXPERIMENTAL STUDIES OF THE
ACOUSTICAL DESIGN OF VEHICLE CABS-A REVIEW OF
TRUCK NOISE SOURCES AND CAB DESIGN USING
STATISTICAL ENERGY ANALYSIS 47
M. J. CROCKER, A. R. PATIL and J. P. ARENAS
1. Introduction 47
2. Noise and vibration sources in heavy vehicles 49
3. SEA and its use in automotive heavy vehicle cab design 53
3.1 SEA model 55
3.2 Resonant and non-resonant transmission 57
3.3 Effect of system parameters 59
4. Total attenuation of an enclosure 60
5. Optimization of enclosure attenuation 60
6. Conclusions 63
References 65
DISTURBANCE DAMPING OF AN UNFOLDED SPACE MIRROR 67
V. I. BUJAKAS
1. Deployable petal-type space antennas 67
2. Kinematic scheme of the unfolded design. 69
3. Mathematical model of petal-type structure dynamics 71
4. Disturbed motion of the frame 72
5. The damping of frame disturbances 73
6. Dynamics of the reflecting surface 75
7. Conclusion 75
References 77
IN PURSUIT OF QUIETER SHIP DESIGN 79
V. BHUJANGA RAO
1. Introduction 79
2. Acoustical Design Considerations 81
2.1 Noise limiting curves 81
2.2 Noise level prediction models 81
2.3 Acoustic quieting techniques 84
2.4 Model experiments 84
2.5 Involvement of shipbuilding yards 85
2.6 Full scale noise measurements 85
2.7 Structural design to overcome transmission paths 86
Contents Vll
2.8 Vibration Isolation 87
2.8.1 Double Stage Mounting System with Acoustic Enclosure 87
2.9 Propeller noise 87
2.10 Radiation from hull structure 89
2.11 Structureborne sound due to acoustic excitation and
transmission to adjacent compartments 90
2.12 Noise transmitted between compartments 91
2.13 Ventilation Noise 91
2.14 Acoustic Enclosures 92
2.15 Flow Noise 93
2.16 Acoustical design scheme of a ship 93
3. Concluding Remarks 94
References 97
ACTIVE CONTROL OF STRUCTURE-BORNE NOISE IN
HELICOPTER CABIN TRANSMITTED THROUGH
GEARBOX SUPPORT STRUT 99
S. GOPALAKRISHNAN and D. ROY MAHAPATRA
1. Introduction 100
1.1 Active Local Control for Structural Wave Guides 103
2. Modeling the Mechanics of Finite-Length Cylindrical Strut 104
2.1 Active Strut with Magnetostrictive Actuators 105
2.2 Kinematics and Equations of Motion for the Cylindrical
Strut Segment 106
3. Spectral Analysis and Characteristic Wave motion 110
4. Active Spectral Element Model (ASEM) 112
4.1 Spectral Element for Finite-Length Strut 113
4.2 Sensor Element and Actuator Input 114
4.3 Actuator Element 115
5. Case Studies 116
5.1 Control of Axial Wave Transmission 116
5.2 Control of Axial-Flexural Coupled Wave Transmission 121
6. Concluding Rmarks 125
References 127
ACITVE NOISE CONTROL IN ACOUSTIC CAVITIES WITH
FLEXIBLE WALLS 129
S. NARAYANAN and C. PADMANABHAN
1. Introduction 129
2. Analytical Formulation for Rectangular Enclosure 131
3. Finite Element Formulation for Cylindrical Cavity 133
3.1 Shell Structure Model 133
3.2 Acoustic Model 135
3.3 Structural-Acoustic Coupling 136
4. Results 137
5. Conclusions 140
Vlll IUTAM SYMPOSIUM ON DESIGNING FOR QUIETNESS
References 145
SEA FOR DIESEL ENGINE TRANSFER PATH 147
DHANESH N. MANIK, PARAG H. MATHURIA
1. Literature Survey 149
2. Theory 150
3. Application of SEA 151
3.1 System Model 151
3.1.1 Subsystem parameters 152
3.2 SEA Model 153
4. Experimental Setup 154
4.1 Modal density 154
4.2 Damping loss factor 154
4.3 Coupling loss factor 156
5. Results and Discussion 156
6. Conclusions 160
Appendix 162
References 165
AN ENVIRONMENTAL IMPACT ASSESSMENT OF A
PROJECTED AIRPORT NOISE 167
K. KONISHI, Z. MAEKAWA
1. Introduction 167
2. Outline of Measurement of Noise Propagation 168
2.1 Measurement Site And The Measuring Measuring System168
2.2 Measured Results For Noise Reduction 169
3. Excess Attenuation Measured In 1/3 Octave Band Noise 171
4. Estimated Excess Attenuation For Aircraft Noise 172
4.1 Estimation of Aircraft Noise 172
4.2 Time Distribution of Excess Attenuation For Estimated
Aircraft Noise 173
4.3 Percentage Distribution of Estimated Excess Attenua
tion For Aircraft noise 173
5. Discussions 174
5.1 Long Range Noise Propagation and Meteorological Con
ditions 174
5.2 Computation Of The Long Range Noise Propagation 176
5.3 Concluding Remarks 176
Appendix 176
References 179
DYNAMICS OF HEARING - SENSITIVITY TO NOISE 181
ALBRECHT EIBER and WERNER SCHIEHLEN
1. Sound Perception and Hearing Process 182
2. Mechanical Model of the Middle Ear 183
3. Risks, Evaluation, Assessment 187
Contents ix
4. Applications 190
4.1 Transient sound 190
4.2 Harmonic sound 193
4.3 Reconstructed ears 194
5. Conclusions 195
References 199
DESIGN OF A MEMS PRESSURE SENSOR FOR ACOUSTIC
APPLICATIONS 201
RUDRA PRATAP and YASH K. DUNGERPURIA
1. Introduction 201
2. Sensor Design 202
3. Damping in the design 204
3.1 Structural damping 205
3.2 Squeeze film damping 205
4. Results and Discussion 206
5. Conclusions 210
References 213
REDUCING RADIATED SOUND POWER BY MINIMIZING THE
DYNAMIC COMPLIANCE 215
C. S. JOG
1. Introduction 215
2. The Dynamic Compliance 218
3. Numerical Examples 222
4. Conclusions 233
References 235
COMPRESSOR RELATED NOISE CONTROL IN
AIR-CONDITIONERS AND REFRIGERATORS 237
S. MANIVASAGAM and J. SENTHILNATHAN
1. Introduction 237
2. Noise Mechanism in Hermetic Compressors 238
3. Compressor Noise Control Techniques 238
3.1 Balance of Rotating and Reciprocating Masses. 238
3.2 Attenuation of Gas Pulsating by Using Efficient Mufflers 238
3.3 Isolation/Suspension 241
3.4 Noise Control by Shell Redesign 242
4. Appliance Noise Control 243
5. Conclusion 244
6. Acknowledgements 245
References 246
x IUTAM SYMPOSIUM ON DESIGNING FOR QUIETNESS
AN EXPERIMENTAL VERIFICATION OF STRUCTURAL-ACOUSTIC
MODELING AND DESIGN OPTIMIZATION 247
H.-i. BEER, i. GIER, H.-i. HARDTKE, S. MARBURG, F. PERRET, R.
RENNERT
1. The Problem 248
2. Model Description 250
2.1 Physical Model 250
2.2 Simulation Model 253
3. Experimental and Simulated Modal Analysis 256
4. Structural and Noise Transfer Functions 258
4.1 Structural Transfer Function 258
4.2 Noise Transfer Function 261
5. Verification of the Simulation Model 265
6. Optimization of the structure 267
6.1 Feasible Modifications 267
6.2 Design Parameters and Objective Function 268
6.3 Optimized Design and its Mode Shapes 270
6.4 Noise Transfer and Objective Functions of Optimized
Design 272
7. Final Remarks 274
References 277
AN OPTIMIZATION TECHNIQUE IN STRUCTURAL-ACOUSTIC
DESIGN OF SEDAN BODY PANELS 279
STEFFEN MARBURG and HANS-JURGEN HARDTKE
1. The problem 279
2. Noise transfer function 283
2.1 General considerations 283
2.2 Structural analysis 284
2.3 Acoustic analysis 285
2.4 Coupling of structure and fluid model 287
3. Design parameters 288
4. Objective function 290
5. Sensitivity analysis 290
6. Applications 291
References 295
HOW NOISE CONTROL IMPROVES HEALTH 299
DEEPAK PRASHER
1. Scale of the Problem of Noise 299
2. Noise and Hearing 300
3. Occupational Noise Exposure: Legal Thresholds 301
4. Susceptibility to noise induced hearing loss 302
5. Environmental Noise and Effects 304
6. Noise and Annoyance 304
7. Noise and Sleep 305
