Applied
Fluid
Mechanics
Sixth Edition
Robert L. Mott
University of Dayton
PEARSON
Prentkv
Contents
CHAPTER 1
THE NATURE OF FLUIDS AND THE STUDY OF FLUID MECHANICS
1.1 The Big Picture 1 1.2 Objectives 3
1.3 Basic Introductory Concepts 3
1.4 The International System of Units (SI) 4 1.5 The U.S. Customary System 5
1.6 Weight and Mass 6 1.7 Temperature 8
1.8 Consistent Units in an Equation 9 1.9 The Definition of Pressure 11 1.10 Compressibility 13
1.11 Density, Specific Weight, and Specific Gravity 14 1.12 Surface Tension 19
References 21 Internet Sites 21 Practice Problems 21
Computer Programming Assignments 24
CHAPTER 2
VISCOSITY OF FLUIDS , 26
2.1 The Big Picture 26 2.2 Objectives 26
2.3 Dynamic Viscosity 27 2.4 Kinematic Viscosity 29
2.5 Newtonian Fluids and Non-Newtonian Fluids 30 2.6 Variation of Viscosity with Temperature 33 2.7 Viscosity Measurement 35
2.8 SAE Viscosity Grades 44 2.9 ISO Viscosity Grades 46
2.10 Hydraulic Fluids for Fluid Power Systems 46 References 48
Internet Sites 48 Practice Problems 49
Computer Programming Assignments 51
viii Contents
CHAPTER 3
PRESSURE MEASUREMENT 52
3.1 The Big Picture 52 3.2 Objectives 52
3.3 Absolute and Gage Pressure 53
3.4 Relationship between Pressure and Elevation 55
3.5 Development of the Pressure-Elevation Relation 57 3.6 Pascal's Paradox 61
3.7 Manometers 62 3.8 Barometers 67
3.9 Pressure Expressed as the Height of a Column of Liquid 69
3.10 Pressure Gages and Transducers 70
References 74 Internet Sites 75 Practice Problems 75
CHAPTER 4
FORCES DUE TO STATIC FLUIDS 83
4.1 The Big Picture 83 4.2 Objectives 85
4.3 Gases under Pressure 85
4.4 Horizontal Flat Surfaces under Liquids 86
4.5 Rectangular Walls 87
4.6 Submerged Plane Areas—General 90
4.7 Development of the General Procedure for Forces on Submerged Plane Areas 94
4.8 Piezometric Head 96
4.9 Distribution of Force on a Submerged Curved Surface 97
4.10 Effect of a Pressure above the Ruid Surface 103 4.11 Forces on a Curved Surface with Ruid Below It 103
4.12 Forces on Curved Surfaces with Ruid Above and Below 104
Practice Problems 105
Computer Programming Assignments 122,
CHAPTER 5
BUOYANCY AND STABILITY 123
5.1 The Big Picture 123 5.2 Objectives 124 5.3 Buoyancy 124
5.4 Buoyancy Materials 132
5.5 Stability of Completely Submerged Bodies 133 5.6 Stability of Floating Bodies 135
5.7 Degree of Stability 140 Reference 142
Internet Sites 142 Practice Problems 142
Contents ix
CHAPTER 6
FLOW OF FLUIDS AND BERNOULLI'S EQUATION 153
6.1 The Big Picture 153
6.2 Objectives 154
6.3 Fluid Row Rate and the Continuity Equation 154 6.4 Commercially Available Pipe and Tubing 158
6.5 Recommended Velocity of Flow in Pipe and Tubing 161
6.6 Conservation of Energy—Bernoulli's Equation 165
6.7 Interpretation of Bernoulli's Equation 167
6.8 Restrictions on Bernoulli's Equation 169
6.9 Applications of Bernoulli's Equation 169
6.10 Torricelli's Theorem 179 6.11 Flow Due to a Falling Head 182
References 185 Internet Sites 185 Practice Problems 186
Computer Programming Assignments 196
CHAPTER 7
GENERAL ENERGY EQUATION 197
7.1 The Big Picture 197 7.2 Objectives 199
7.3 Energy Losses and Additions 199
7.4 Nomenclature of Energy Losses and Additions 202 7.5 General Energy Equation 202
7.6 Power Required by Pumps 207 7.7 Power Delivered to Fluid Motors 211
Practice Problems 213
CHAPTER 8
REYNOLDS NUMBER, LAMINAR FLOW, TURBULENT
FLOW, AND ENERGY LOSSES DUE TO FRICTION 226
8.1 The Big Picture 226
8.2 Objectives 229 8.3 Reynolds Number 230
8.4 Critical Reynolds Numbers 231 8.5 Darcy's Equation 233
8.6 Friction Loss in Laminar Flow 233
8.7 Friction Loss in Turbulent Flow 235
8.8 Equations for the Friction Factor 242
8.9 Hazen-Williams Formula for Water Flow 243
8.10 Other Forms of the Hazen-Williams Formula 245
8.11 Nomograph for Solving the Hazen-Williams Formula 245
References 247 Internet Sites 247 Practice Problems 247
Contents
CHAPTER 9
VELOCITY PROFILES FOR CIRCULAR SECTIONS
AND FLOW IN NONCIRCULAR SECTIONS 255
9.1 The Big Picture 255 9.2 Objectives 256 9.3 Velocity Profiles 256
9.4 Velocity Profile for Laminar Row 257 9.5 Velocity Profile for Turbulent Flow 258 9.6 Flow in Noncircular Sections 260 9.7 Computational Fluid Dynamics 266
References 268 Internet Sites 268 Practice Problems 268
Computer Programming Assignments 277
CHAPTER 10
MINOR LOSSES 278
10.1 The Big Picture 278 10.2 Objectives 280 10.3 Resistance Coefficient 281 10.4 Sudden Enlargement 281 10.5 Exit Loss 284 10.6 Gradual Enlargement 286 10.7 Sudden Contraction 288 10.8 Gradual Contraction 290 10.9 Entrance Loss 292
10.10 Resistance Coefficients for Valves and Fittings 293 10.11 Application of Standard Valves 300
10.12 Pipe Bends 303
10.13 Pressure Drop in Ruid Power Valves 305 10.14 Flow Coefficients for Valves Using Cy 310 10.15 Plastic Valves 311
References 313 Internet Sites 313 Practice Problems 314
Computer-Aided Analysis and Design Assignments 319
CHAPTER 11
SERIES PIPELINE SYSTEMS 320
11.1 The Big Picture 320 11.2 Objectives 321 11.3 Class I Systems 321
11.4 Spreadsheet Aid for Class I Problems 327 11.5 Class II Systems 330
11.6 Class III Systems 339
11.7 Pipeline Design for Structural Integrity 343
Contents xi Internet Sites 346
Practice Problems 346
Computer-Aided Analysis and Design Assignments 357
CHAPTER 12
PARALLEL PIPELINE SYSTEMS 358 12.1 The Big Picture 358
12.2 Objectives 360
12.3 Systems with Two Branches 361
12.4 Systems with Three or More Branches—Networks 368
Reference 377 Internet Sites 377 Practice Problems 377
Computer Programming Assignments 381
CHAPTER 13
PUMP SELECTION AND APPLICATION 382 13.1 The Big Picture 382
13.2 Objectives 384
13.3 Parameters Involved in Pump Selection 385 13.4 Types of Pumps 385
13.5 Positive-Displacement Pumps 385 13.6 Kinetic Pumps 392
13.7 Performance Data for Centrifugal Pumps 398 13.8 Affinity Laws for Centrifugal Pumps 400 13.9 Manufacturers' Data for Centrifugal Pumps 401
13.10 The Operating Point of a Pump and Pump Selection 410 13.11 Net Positive Suction Head 411
13.12 Suction Line Details 417 13.13 Discharge Line Details 418
13.14 Piping System Design and Pump Selection Procedure 419 13.15 Alternate System Operating Modes 423
13.16 Pump Selection and Specific Speed 429
13.17 Life Cycle Costs for Pumped Fluid Systems 430
13.18 Software for Piping System Design and Pump Selection 433
References 434 Internet Sites 434
Software for Piping System Design 435 Practice Problems 436
Design Problems 438
Comprehensive Design Problem 441
CHAPTER 14
OPEN-CHANNEL FLOW 443 14.1 The Big Picture 443
14.2 Objectives 444
xii Contents
14.4 Hydraulic Radius and Reynolds Number in Open-Channel
Flow 446
14.5 Kinds of Open-Channel Flow 447
14.6 Uniform Steady Flow in Open Channels 448 14.7 The Geometry of Typical Open Channels 453 14.8 The Most Efficient Shapes for Open Channels 456 14.9 Critical Row and Specific Energy 457
14.10 Hydraulic Jump 459
14.11 Open-Channel Flow Measurement 462
References 467 Internet Sites 467 Practice Problems 468
Computer Programming Assignments 471
CHAPTER 15
FLOW MEASUREMENT 473
15.1 The Big Picture 473 15.2 Objectives 474
15.3 Rowmeter Selection Factors 474 15.4 Variable-Head Meters 476 15.5 Variable-Area Meters 485 15.6 Turbine Flowmeter 486 15.7 Vortex Flowmeter 487 15.8 Magnetic Rowmeter 487 15.9 Ultrasonic Flowmeters 489 15.10 Positive Displacement Meters 489 15.11 Mass Row Measurement 490 15.12 Velocity Probes 492
15.13 Level Measurement 497
15.14 Computer-Based Data Acquisition and Processing 499
References 499 Internet Sites 499 Review Questions 500
Practice Problems 501 . Computer Programming Assignments 502
CHAPTER 16
FORCES DUE TO FLUIDS IN MOTION 503
16.1 The Big Picture 503 16.2 Objectives 504 16.3 Force Equation 504
16.4 Impulse-Momentum Equation 505
16.5 Problem-Solving Method Using the Force Equations 505 16.6 Forces on Stationary Objects 506
16.7 Forces on Bends in Pipelines 509 16.8 Forces on Moving Objects 513
Contents xiii
CHAPTER 17
DRAG AND LIFT 520
17.1 The Big Picture 520 17.2 Objectives 521
17.3 Drag Force Equation 522 17.4 Pressure Drag 523 17.5 Drag Coefficient 524
17.6 Friction Drag on Spheres in Laminar Flow 530 17.7 Vehicle Drag 531
17.8 Compressibility Effects and Cavitation 533 17.9 Lift and Drag on Airfoils 534
References 537 Internet Sites 537 Practice Problems 537
CHAPTER 18
FANS, BLOWERS, COMPRESSORS, AND
THE FLOW OF GASES 542 18.1 The Big Picture 542
18.2 Objectives 543
18.3 Gas Flow Rates and Pressures 543
18.4 Classification of Fans, Blowers, and Compressors 544 18.5 Flow of Compressed Air and Other Gases in Pipes 549 18.6 Flow of Air and Other Gases through Nozzles 556
References 564 Internet Sites 564 Practice Problems 565
Computer Programming Assignments 567
CHAPTER 19
FLOW OF AIR IN DUCTS 568 19.1 The Big Picture 568
19.2 Objectives 570
19.3 Energy Losses in Ducts 570 19.4 Duct Design 576
19.5 Energy Efficiency and Practical Considerations
in Duct Design 583 References 584 Internet Sites 584 Practice Problems 585 APPENDIXES 589 A Properties of Water 589
B Properties of Common Liquids 591
xiv Contents
D Variation of Viscosity with Temperature 594 E Properties of Air 597
F Dimensions of Steel Pipe 601 G Dimensions of Steel Tubing 603
H Dimensions of Type K Copper Tubing 604 I Dimensions of Ductile Iron Pipe 605 J Areas of Circles 606
K Conversion Factors 608 L Properties of Areas 611 M Properties of Solids 613
N Gas Constant, Adiabatic Exponent, and Critical Pressure Ratio for Selected Gases 615