Industrial Noise Control and Acoustics

by Randall F. Barron

Overview

Barron is professor emeritus of mechanical engineering at Louisiana Tech U., Ruston. His textbook is based on 30 years of experience teaching mechanical engineering courses in noise control to undergraduate and graduate students, continuing education courses for practicing professionals, and consulting on industrial projects in noise assessment and abatement. The text integrates the theory of acoustics with the practice of noise control engineering, and includes eight case studies which demonstrate practical solutions for noise problems in industry. It would also be suitable as a reference text for practicing engineers. Annotation c. Book News, Inc., Portland, OR

Product Details

ISBN-13:	9780203910085
Publisher:	CRC Press
Publication date:	11/14/2002
Series:	Mechanical Engineering
Sold by:	Barnes & Noble
Format:	eBook
Pages:	552
File size:	22 MB
Note:	This product may take a few minutes to download.

About the Author

RANDALL F. BARRON is Professor Emeritus of Mechanical Engineering, Louisiana Tech University, Ruston. The author of numerous professional publications, he is a Fellow of the American Society of Mechanical Engineers and a member of the American Society for Engineering Education and the Cryogenic Society of America, among other organizations. He received the B.S. degree (1958) in mechanical engineering from Louisiana Tech University, Ruston, and the M.S. (1961) and Ph.D. (1964) degrees in mechanical engineering from The Ohio State University, Columbus.

Table of Contents

	Preface	iii
1	Introduction	1
1.1	Noise Control	1
1.2	Historical Background	3
1.3	Principles of Noise Control	7
1.3.1	Noise Control at the Source	8
1.3.2	Noise Control in the Transmission Path	9
1.3.3	Noise Control at the Receiver	9
	References	10
2	Basics of Acoustics	12
2.1	Speed of Sound	12
2.2	Wavelength, Frequency, and Wave Number	13
2.3	Acoustic Pressure and Particle Velocity	15
2.4	Acoustic Intensity and Acoustic Energy Density	17
2.5	Spherical Waves	21
2.6	Directivity Factor and Directivity Index	24
2.7	Levels and the Decibel	27
2.8	Combination of Sound Sources	31
2.9	Octave Bands	33
2.10	Weighted Sound Levels	34
	Problems	37
	References	40
3	Acoustic Measurements	41
3.1	Sound Level Meters	42
3.2	Intensity Level Meters	46
3.3	Octave Band Filters	49
3.4	Acoustic Analyzers	50
3.5	Dosimeter	50
3.6	Measurement of Sound Power	51
3.6.1	Sound Power Measurement in a Reverberant Room	52
3.6.2	Sound Power Measurement in an Anechoic or Semi-Anechoic Room	58
3.6.3	Sound Power Survey Measurements	62
3.6.4	Measurement of the Directivity Factor	66
3.7	Noise Measurement Procedures	69
	Problems	73
	References	76
4	Transmission of Sound	78
4.1	The Wave Equation	78
4.2	Complex Number Notation	83
4.3	Wave Equation Solution	84
4.4	Solution for Spherical Waves	88
4.5	Changes in Media with Normal Incidence	91
4.6	Changes in Media with Oblique Incidence	96
4.7	Sound Transmission Through a Wall	101
4.8	Transmission Loss for Walls	107
4.8.1	Region I: Stiffness-Controlled Region	108
4.8.2	Resonant Frequency	111
4.8.3	Region II: Mass-Controlled Region	112
4.8.4	Critical Frequency	113
4.8.5	Region III: Damping-Controlled Region	113
4.9	Approximate Method for Estimating the TL	117
4.10	Transmission Loss for Composite Walls	120
4.10.1	Elements in Parallel	121
4.10.2	Composite Wall with Air Space	122
4.10.3	Two-Layer Laminate	127
4.10.4	Rib-Stiffened Panels	131
4.11	Sound Transmission Class	134
4.12	Absorption of Sound	139
4.13	Attenuation Coefficient	143
	Problems	153
	References	160
5	Noise Sources	162
5.1	Sound Transmission Indoors and Outdoors	162
5.2	Fan Noise	164
5.3	Electric Motor Noise	169
5.4	Pump Noise	171
5.5	Gas Compressor Noise	173
5.6	Transformer Noise	177
5.7	Cooling Tower Noise	178
5.8	Noise from Gas Vents	182
5.9	Appliance and Equipment Noise	185
5.10	Valve Noise	186
5.10.1	Sources of Valve Noise	186
5.10.2	Noise Prediction for Gas Flows	188
5.10.3	Noise Prediction for Liquid Flows	190
5.11	Air Distribution System Noise	192
5.11.1	Noise Attenuation in Air Distribution Systems	193
5.11.2	Noise Generation in Air Distribution System Fittings	195
5.11.3	Noise Generation in Grilles	198
5.12	Traffic Noise	207
5.13	Train Noise	211
5.13.1	Railroad Car Noise	211
5.13.2	Locomotive Noise	213
5.13.3	Complete Train Noise	214
	Problems	217
	References	222
6	Acoustic Criteria	225
6.1	The Human Ear	226
6.2	Hearing Loss	229
6.3	Industrial Noise Criteria	231
6.4	Speech Interference Level	235
6.5	Noise Criteria for Interior Spaces	238
6.6	Community Reaction to Environmental Noise	243
6.7	The Day-Night Level	247
6.7.1	EPA Criteria	247
6.7.2	Estimation of Community Reaction	250
6.8	HUD Criteria	253
6.9	Aircraft Noise Criteria	255
6.9.1	Perceived Noise Level	256
6.9.2	Noise Exposure Forecast	257
	Problems	262
	References	267
7	Room Acoustics	269
7.1	Surface Absorption Coefficients	269
7.1.1	Values for Surface Absorption Coefficients	269
7.1.2	Noise Reduction Coefficient	270
7.1.3	Mechanism of Acoustic Absorption	271
7.1.4	Average Absorption Coefficient	274
7.2	Steady-State Sound Level in a Room	274
7.3	Reverberation Time	281
7.4	Effect of Energy Absorption in the Air	289
7.4.1	Steady-State Sound Level with Absorption in the Air	289
7.4.2	Reverberation Time with Absorption in the Air	291
7.5	Noise from an Adjacent Room	293
7.5.1	Sound Source Covering One Wall	293
7.5.2	Sound Transmission from an Adjacent Room	295
7.6	Acoustic Enclosures	299
7.6.1	Small Acoustic Enclosures	300
7.6.2	Large Acoustic Enclosures	304
7.6.3	Design Practice for Enclosures	311
7.7	Acoustic Barriers	312
7.7.1	Barriers Located Outdoors	313
7.7.2	Barriers Located Indoors	317
	Problems	321
	References	328
8	Silencer Design	330
8.1	Silencer Design Requirements	330
8.2	Lumped Parameter Analysis	332
8.2.1	Acoustic Mass	332
8.2.2	Acoustic Compliance	335
8.2.3	Acoustic Resistance	338
8.2.4	Transfer Matrix	339
8.3	The Helmholtz Resonator	341
8.3.1	Helmholtz Resonator System	341
8.3.2	Resonance for the Helmholtz Resonator	342
8.3.3	Acoustic Impedance for the Helmholtz Resonator	343
8.3.4	Half-Power Bandwidth	344
8.3.5	Sound Pressure Level Gain	348
8.4	Side Branch Mufflers	350
8.4.1	Transmission Loss for a Side-Branch Muffler	351
8.4.2	Directed Design Procedure for Side-Branch Mufflers	357
8.4.3	Closed Tube as a Side-Branch Muffler	361
8.4.4	Open Tube (Orifice) as a Side Branch	365
8.5	Expansion Chamber Mufflers	368
8.5.1	Transmission Loss for an Expansion Chamber Muffler	368
8.5.2	Design Procedure for Single-Expansion Chamber Mufflers	371
8.5.3	Double-Chamber Mufflers	373
8.6	Dissipative Mufflers	377
8.7	Evaluation of the Attenuation Coefficient	381
8.7.1	Estimation of the Attenuation Coefficient	381
8.7.2	Effective Density	383
8.7.3	Effective Elasticity Coefficient	384
8.7.4	Effective Specific Flow Resistance	385
8.7.5	Correction for Random Incidence End Effects	387
8.8	Commercial Silencers	389
8.9	Plenum Chambers	391
	Problems	397
	References	405
9	Vibration Isolation for Noise Control	406
9.1	Undamped Single-Degree-of-Freedom (SDOF) System	407
9.2	Damped Single-Degree-of-Freedom (SDOF) System	410
9.2.1	Critically Damped System	411
9.2.2	Over-Damped System	412
9.2.3	Under-Damped System	412
9.3	Damping Factors	413
9.4	Forced Vibration	419
9.5	Mechanical Impedance and Mobility	424
9.6	Transmissibility	427
9.7	Rotating Unbalance	431
9.8	Displacement Excitation	436
9.9	Dynamic Vibration Isolator	439
9.10	Vibration Isolation Materials	446
9.10.1	Cork and Felt Resilient Materials	446
9.10.2	Rubber and Elastomer Vibration Isolators	450
9.10.3	Metal Spring Isolators	457
9.11	Effects of Vibration on Humans	464
	Problems	469
	References	474
10	Case Studies in Noise Control	475
10.1	Introduction	475
10.2	Folding Carton Packing Station Noise	476
10.2.1	Analysis	476
10.2.2	Control Approach Chosen	479
10.2.3	Cost	479
10.2.4	Pitfalls	480
10.3	Metal Cut-Off Saw Noise	480
10.3.1	Analysis	480
10.3.2	Control Approach Chosen	481
10.3.3	Cost	482
10.3.4	Pitfalls	482
10.4	Paper Machine Wet End	482
10.4.1	Analysis	483
10.4.2	Control Approach Chosen	487
10.4.3	Cost	487
10.4.4	Pitfalls	488
10.5	Air Scrap Handling Duct Noise	488
10.5.1	Analysis	488
10.5.2	Control Approach Chosen	491
10.5.3	Cost	492
10.5.4	Pitfalls	492
10.6	Air-Operated Hoist Motor	492
10.7	Blanking Press Noise	494
10.7.1	Analysis	495
10.7.2	Control Approach Chosen	497
10.7.3	Cost	497
10.7.4	Pitfalls	497
10.8	Noise in a Small Meeting Room	498
10.8.1	Analysis	499
10.8.2	Control Approach Chosen	502
10.8.3	Cost	503
10.8.4	Pitfalls	503
	Problems	503
	References	504
Appendix A	Preferred Prefixes in SI	506
Appendix B	Properties of Gases, Liquids, and Solids	507
Appendix C	Plate Properties of Solids	509
Appendix D	Surface Absorption Coefficients	510
Appendix E	Nomenclature	514
	Index	525