Fundamentals of Hydraulic Engineering Systems (5th Edition)

PREFACE xi
ACKNOWLEDGMENTS xv
INTRODUCTION xix
1 FUNDAMENTAL PROPERTIES OF WATER 1
1.1 The Earth’s Atmosphere and Atmospheric Pressure 2
1.2 The Three Phases of Water 2
1.3 Mass (Density) and Weight (Specific Weight) 3
1.4 Viscosity of Water 5
1.5 Surface Tension and Capillarity 7
1.6 Elasticity of Water 8
1.7 Forces in a Fluid Field 10
Problems 10
vi Contents
2 WATER PRESSURE AND PRESSURE FORCES 14
2.1 The Free Surface of Water 14
2.2 Absolute and Gauge Pressures 14
2.3 Surfaces of Equal Pressure 17
2.4 Manometers 19
2.5 Hydrostatic Forces on Flat Surfaces 23
2.6 Hydrostatic Forces on Curved Surfaces 28
2.7 Buoyancy 31
2.8 Flotation Stability 33
Problems 37
3 WATER FLOW IN PIPES 54
3.1 Description of Pipe Flow 54
3.2 The Reynolds Number 55
3.3 Continuity and Momentum Equations in Pipe Flow 57
3.4 Energy in Pipe Flow 60
3.5 Loss of Head from Pipe Friction 63
3.5.1 Friction Factor for Laminar Flow 64
3.5.2 Friction Factor for Turbulent Flow 65
3.6 Empirical Equations for Friction Head Loss 71
3.7 Friction Head Loss–Discharge Relationships 74
3.8 Loss of Head in Pipe Contractions 75
3.9 Loss of Head in Pipe Expansions 78
3.10 Loss of Head in Pipe Bends 79
3.11 Loss of Head in Pipe Valves 81
3.12 Method of Equivalent Pipes 84
3.12.1 Pipes in Series 84
3.12.2 Pipes in Parallel 85
Problems 87
4 PIPELINES AND PIPE NETWORKS 94
4.1 Pipelines Connecting Two Reservoirs 94
4.2 Negative Pressure Scenarios (Pipelines and Pumps) 98
4.3 Branching Pipe Systems 103
4.4 Pipe Networks 110
4.4.1 The Hardy–Cross Method 111
4.4.2 The Newton Method 122
Contents vii
4.5 Water Hammer Phenomenon in Pipelines 125
4.6 Surge Tanks 134
4.7 Pipe Network Modeling 136
4.7.1 The EPANET Model 137
Problems 141
5 WATER PUMPS 155
5.1 Centrifugal (Radial Flow) Pumps 155
5.2 Propeller (Axial Flow) Pumps 161
5.3 Jet (Mixed-Flow) Pumps 164
5.4 Centrifugal Pump Characteristic Curves 165
5.5 Single Pump and Pipeline Analysis 166
5.6 Pumps in Parallel or in Series 169
5.7 Pumps and Branching Pipes 173
5.8 Pumps and Pipe Networks 176
5.9 Cavitation in Water Pumps 177
5.10 Specific Speed and Pump Similarity 181
5.11 Selection of a Pump 183
Problems 187
6 WATER FLOW IN OPEN CHANNELS 197
6.1 Open-Channel Flow Classifications 199
6.2 Uniform Flow in Open Channels 201
6.3 Hydraulic Efficiency of Open-Channel Sections 207
6.4 Energy Principles in Open-Channel Flow 210
6.5 Hydraulic Jumps 216
6.6 Gradually Varied Flow 219
6.7 Classifications of Gradually Varied Flow 221
6.8 Computation of Water Surface Profiles 224
6.8.1 Standard Step Method 225
6.8.2 Direct Step Method 227
6.9 Hydraulic Design of Open Channels 234
6.9.1 Unlined Channels 236
6.9.2 Rigid Boundary Channels 238
6.10 Open Channel Flow Modeling 239
6.10.1 The HEC-RAS Model 240
Problems 245
viii Contents
7 GROUNDWATER HYDRAULICS 253
7.1 Movement of Groundwater 255
7.2 Steady Radial Flow to a Well 258
7.2.1 Steady Radial Flow in Confined Aquifers 259
7.2.2 Steady Radial Flow in Unconfined Aquifers 261
7.3 Unsteady Radial Flow to a Well 263
7.3.1 Unsteady Radial Flow in Confined Aquifers 263
7.3.2 Unsteady Radial Flow in Unconfined Aquifers 267
7.4 Field Determination of Aquifer Characteristics 270
7.4.1 Equilibrium Test in Confined Aquifers 271
7.4.2 Equilibrium Test in Unconfined Aquifers 273
7.4.3 Nonequilibrium Test 275
7.5 Aquifer Boundaries 279
7.6 Surface Investigations of Groundwater 285
7.6.1 The Electrical Resistivity Method 285
7.6.2 Seismic Wave Propagation Methods 285
7.7 Seawater Intrusion in Coastal Areas 286
7.8 Seepage Through Dam Foundations 291
7.9 Seepage Through Earth Dams 294
Problems 296
8 HYDRAULIC STRUCTURES 307
8.1 Functions of Hydraulic Structures 307
8.2 Dams: Functions and Classifications 308
8.3 Stability of Gravity and Arch Dams 311
8.3.1 Gravity Dams 311
8.3.2 Arch Dams 314
8.4 Small Earth Dams 316
8.5 Weirs 318
8.6 Overflow Spillways 323
8.7 Side-Channel Spillways 326
8.8 Siphon Spillways 328
8.9 Culverts 331
8.10 Stilling Basins 336
Problems 340
Contents ix
9 WATER PRESSURE, VELOCITY, AND DISCHARGE MEASUREMENTS 347
9.1 Pressure Measurements 347
9.2 Velocity Measurements 349
9.3 Discharge Measurements in Pipes 352
9.4 Discharge Measurements in Open Channels 357
9.4.1 Sharp-Crested Weirs 357
9.4.2 Broad-Crested Weirs 360
9.4.3 Venturi Flumes 361
Problems 366
10 HYDRAULIC SIMILITUDE AND MODEL STUDIES 371
10.1 Dimensional Homogeneity 372
10.2 Principles of Hydraulic Similitude 373
10.3 Phenomena Governed by Viscous
Forces: Reynolds Number Law 378
10.4 Phenomena Governed by Gravity
Forces: Froude Number Law 381
10.5 Phenomena Governed by Surface
Tension: Weber Number Law 383
10.6 Phenomena Governed by Both
Gravity and Viscous Forces 384
10.7 Models for Floating and Submerged Bodies 384
10.8 Open-Channel Models 386
10.9 The Pi Theorem 388
Problems 392
11 HYDROLOGY FOR HYDRAULIC DESIGN 397
11.1 Watershed Delineation 399
11.2 Design Storms 400
11.2.1 Storm Hyetograph 401
11.2.2 Intensity–Duration–Return
Period Relationships 402
11.2.3 Design-Storm Selection 402
11.2.4 Synthetic Block Design-Storm Hyetograph 404
11.2.5 Soil Conservation Service Hyetographs 405
11.3 Losses from Rainfall and Rainfall Excess 408
11.3.1 Green and Ampt Infiltration Model 410
11.3.2 Soil Conservation Service Method 413
x Contents
11.4 Design Runoff Hydrographs 415
11.4.1 Time of Concentration 416
11.4.2 Unit Hydrograph 419
11.4.3 Total Runoff Hydrograph 424
11.5 Storage Routing 426
11.6 Hydraulic Design: The Rational Method 435
11.6.1 Design of Stormwater-Collection Systems 437
11.6.2 Design of Stormwater Pipes 439
11.7 Hydrologic Modeling 443
11.7.1 The HEC-HMS Model 444
11.7.2 The EPA-SWMM Model 447
Problems 451
12 STATISTICAL METHODS IN HYDROLOGY 463
12.1 Concepts of Probability 464
12.2 Statistical Parameters 464
12.3 Probability Distributions 468
12.3.1 Normal Distribution 468
12.3.2 Log-Normal Distribution 469
12.3.3 Gumbel Distribution 469
12.3.4 Log-Pearson Type III Distribution 470
12.4 Return Period and Hydrologic Risk 472
12.5 Frequency Analysis 473
12.5.1 Frequency Factors 473
12.5.2 Testing Goodness of Fit 476
12.5.3 Confidence Limits 478
12.6 Frequency Analysis Using Probability Graphs 481
12.6.1 Probability Graphs 481
12.6.2 Plotting Positions 481
12.6.3 Data Plotting and Theoretical Distributions 483
12.6.4 Estimating Future Magnitudes 484
12.7 Rainfall Intensity-Duration-Frequency Relationships 485
12.8 Applicability of Statistical Methods 488
Problems 488
SYMBOLS 493
ANSWERS TO SELECTED PROBLEMS 496
INDEX 502