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assignments and presentations. FAQs, online chat, Personal training and Created by subject matter experts. and phone support.com/support www.com Fox and McDonald’s INTRODUCTION TO FLUID MECHANICS EIGHTH EDITION PHILIP J. PRITCHARD Manhattan College With special contributions from: JOHN C.
LEYLEGIAN Manhattan College JOHN WILEY & SONS, INC.com VICE PRESIDENT AND EXECUTIVE PUBLISHER Don Fowley ASSOCIATE PUBLISHER Daniel Sayre AQUISITIONS EDITOR Jennifer Welter EDITORIAL ASSISTANT Alexandra Spicehandler MARKETING MANAGER Christopher Ruel MEDIA EDITOR Elena Santa Maria CREATIVE DIRECTOR Harold Nolan SENIOR DESIGNER Kevin Murphy SENIOR ILLUSTRATION EDITOR Anna Melhorn PHOTO EDITOR Sheena Goldstein PRODUCTION MANAGER Dorothy Sinclair SENIOR PRODUCTION EDITOR Trish McFadden PRODUCTION MANAGEMENT SERVICES MPS Limited, A Macmillan Company COVER DESIGN Wendy Lai COVER PHOTO rsupertramp/iStockphoto CFD simulation image courtesy of Symscape at www.com CHAPTER OPENING PHOTO Dr. Charles O’Neill, Oklahoma State University This book was set in Times Roman by MPS Limited, A Macmillan Company and printed and bound by R. The cover was printed by R. This book is printed on acid-free paper.
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ISBN-13 9780470547557 ISBN-10 0470547553 Printed in the United States of America 10 9 8 7 6 5 4 3 2 1 www.com Contents CHAPTER 1 INTRODUCTION /1 1.1 Note to Students /3 1.2 Scope of Fluid Mechanics /4 1.3 Definition of a Fluid /4 1.5 Methods of Analysis /6 System and Control Volume /7 Differential versus Integral Approach /8 Methods of Description /9 1.6 Dimensions and Units /11 Systems of Dimensions /11 Systems of Units /11 Preferred Systems of Units /13 Dimensional Consistency and “Engineering” Equations /14 1.7 Analysis of Experimental Error /15 1.8 Summary /16 Problems /17 CHAPTER 2 FUNDAMENTAL CONCEPTS /20 2.1 Fluid as a Continuum /21 2.2 Velocity Field /23 One-, Two-, and Three-Dimensional Flows /24 Timelines, Pathlines, Streaklines, and Streamlines /25 2.4 Viscosity /31 Newtonian Fluid /32 Non-Newtonian Fluids /34 2.6 Description and Classification of Fluid Motions /38 Viscous and Inviscid Flows /38 Laminar and Turbulent Flows /41 Compressible and Incompressible Flows /42 Internal and External Flows /43 2.7 Summary and Useful Equations /44 v www.com vi Contents References /46 Problems /46 CHAPTER 3 FLUID STATICS /55 3.1 The Basic Equation of Fluid Statics /56 3.2 The Standard Atmosphere /60 3.3 Pressure Variation in a Static Fluid /61 Incompressible Liquids: Manometers /61 Gases /66 3.5 Hydrostatic Force on Submerged Surfaces /69 Hydrostatic Force on a Plane Submerged Surface /69 Hydrostatic Force on a Curved Submerged Surface /76 *3.6 Buoyancy and Stability /80 3.7 Fluids in Rigid-Body Motion (on the Web) /W-1 3.8 Summary and Useful Equations /83 References /84 Problems /84 CHAPTER 4 BASIC EQUATIONS IN INTEGRAL FORM FOR A CONTROL VOLUME /96 4.1 Basic Laws for a System /98 Conservation of Mass /98 Newton’s Second Law /98 The Angular-Momentum Principle /99 The First Law of Thermodynamics /99 The Second Law of Thermodynamics /99 4.2 Relation of System Derivatives to the Control Volume Formulation /100 Derivation /101 Physical Interpretation /103 4.3 Conservation of Mass /104 Special Cases /105 4.4 Momentum Equation for Inertial Control Volume /110 *Differential Control Volume Analysis /122 Control Volume Moving with Constant Velocity /126 4.5 Momentum Equation for Control Volume with Rectilinear Acceleration /128 4.6 Momentum Equation for Control Volume with Arbitrary Acceleration (on the Web) /W-6 *4.7 The Angular-Momentum Principle /135 Equation for Fixed Control Volume /135 Equation for Rotating Control Volume (on the Web) /W-11 4.8 The First Law of Thermodynamics /139 Rate of Work Done by a Control Volume /140 Control Volume Equation /142 4.9 The Second Law of Thermodynamics /146 4.10 Summary and Useful Equations /147 Problems /149 CHAPTER 5 INTRODUCTION TO DIFFERENTIAL ANALYSIS OF FLUID MOTION /171 5.1 Conservation of Mass /172 Rectangular Coordinate System /173 Cylindrical Coordinate System /177 *5.2 Stream Function for Two-Dimensional Incompressible Flow /180 5.3 Motion of a Fluid Particle (Kinematics) /184 Fluid Translation: Acceleration of a Fluid Particle in a Velocity Field /185 Fluid Rotation /190 Fluid Deformation /194 5.4 Momentum Equation /197 Forces Acting on a Fluid Particle /198 Differential Momentum Equation /199 Newtonian Fluid: Navier Stokes Equations /199 www.com Contents vii *5.5 Introduction to Computational Fluid Dynamics /208 The Need for CFD /208 Applications of CFD /209 Some Basic CFD/Numerical Methods Using a Spreadsheet /210 The Strategy of CFD /215 Discretization Using the Finite-Difference Method /216 Assembly of Discrete System and Application of Boundary Conditions /217 Solution of Discrete System /218 Grid Convergence /219 Dealing with Nonlinearity /220 Direct and Iterative Solvers /221 Iterative Convergence /222 Concluding Remarks /223 5.6 Summary and Useful Equations /224 References /226 Problems /226 CHAPTER 6 INCOMPRESSIBLE INVISCID FLOW /235 6.1 Momentum Equation for Frictionless Flow: Euler’s Equation /237 6.2 Euler’s Equations in Streamline Coordinates /238 6.3 Bernoulli Equation—Integration of Euler’s Equation Along a Streamline for Steady Flow /241 *Derivation Using Streamline Coordinates /241 *Derivation Using Rectangular Coordinates /242 Static, Stagnation, and Dynamic Pressures /244 Applications /247 Cautions on Use of the Bernoulli Equation /252 6.4 The Bernoulli Equation Interpreted as an Energy Equation /253 6.5 Energy Grade Line and Hydraulic Grade Line /257 *6.6 Unsteady Bernoulli Equation: Integration of Euler’s Equation Along a Streamline (on the Web) /W-16 *6.7 Irrotational Flow /259 Bernoulli Equation Applied to Irrotational Flow /260 Velocity Potential /261 Stream Function and Velocity Potential for Two-Dimensional, Irrotational, Incompressible Flow: Laplace’s Equation /262 Elementary Plane Flows /264 Superposition of Elementary Plane Flows /267 6.8 Summary and Useful Equations /276 References /279 Problems /279 CHAPTER 7 DIMENSIONAL ANALYSIS AND SIMILITUDE /290 7.1 Nondimensionalizing the Basic Differential Equations /292 7.2 Nature of Dimensional Analysis /294 7.3 Buckingham Pi Theorem /296 7.4 Determining the Π Groups /297 7.5 Significant Dimensionless Groups in Fluid Mechanics /303 7.6 Flow Similarity and Model Studies /305 Incomplete Similarity /308 Scaling with Multiple Dependent Parameters /314 Comments on Model Testing /317 7.7 Summary and Useful Equations /318 References /319 Problems /320 CHAPTER 8 INTERNAL INCOMPRESSIBLE VISCOUS FLOW /328 8.1Introduction /330 Laminar versus Turbulent Flow /330 The Entrance Region /331 PART A. FULLY DEVELOPED LAMINAR FLOW /332 www.com viii Contents 8.2 Fully Developed Laminar Flow between Infinite Parallel Plates /332 Both Plates Stationary /332 Upper Plate Moving with Constant Speed, U /338 8.3 Fully Developed Laminar Flow in a Pipe /344 PART B. FLOW IN PIPES AND DUCTS /348 8.4 Shear Stress Distribution in Fully Developed Pipe Flow /349 8.5 Turbulent Velocity Profiles in Fully Developed Pipe Flow /351 8.6 Energy Considerations in Pipe Flow /353 Kinetic Energy Coefficient /355 Head Loss /355 8.7 Calculation of Head Loss /357 Major Losses: Friction Factor /357 Minor Losses /361 Pumps, Fans, and Blowers in Fluid Systems /367 Noncircular Ducts /368 8.8 Solution of Pipe Flow Problems /369 Single-Path Systems /370 *Multiple-Path Systems /383 PART C.10 Restriction Flow Meters for Internal Flows /387 The Orifice Plate /391 The Flow Nozzle /391 The Venturi /393 The Laminar Flow Element /394 8.11 Linear Flow Meters /397 8.13 Summary and Useful Equations /400 References /402 Problems /403 CHAPTER 9 EXTERNAL INCOMPRESSIBLE VISCOUS FLOW /421 PART A.1 The Boundary-Layer Concept /423 9.2 Boundary-Layer Thicknesses /425 9.3 Laminar Flat-Plate Boundary Layer: Exact Solution (on the Web) /W-19 9.4 Momentum Integral Equation /428 9.5 Use of the Momentum Integral Equation for Flow with Zero Pressure Gradient /433 Laminar Flow /434 Turbulent Flow /439 Summary of Results for Boundary-Layer Flow with Zero Pressure Gradient /441 9.6 Pressure Gradients in Boundary-Layer Flow /442 PART B.
FLUID FLOW ABOUT IMMERSED BODIES /445 9.7 Drag /445 Pure Friction Drag: Flow over a Flat Plate Parallel to the Flow /446 Pure Pressure Drag: Flow over a Flat Plate Normal to the Flow /450 Friction and Pressure Drag: Flow over a Sphere and Cylinder /450 Streamlining /456 9.9 Summary and Useful Equations /474 References /477 Problems /478 CHAPTER 10 FLUID MACHINERY /492 10.1 Introduction and Classification of Fluid Machines /494 Machines for Doing Work on a Fluid /494 Machines for Extracting Work (Power) from a Fluid /496 Scope of Coverage /498 10.2 Turbomachinery Analysis /499 The Angular-Momentum Principle: The Euler Turbomachine Equation /499 Velocity Diagrams /501 www.com Contents ix Performance: Hydraulic Power /504 Dimensional Analysis and Specific Speed /505 10.3 Pumps, Fans, and Blowers /510 Application of Euler Turbomachine Equation to Centrifugal Pumps /510 Application of the Euler Equation to Axial Flow Pumps and Fans /512 Performance Characteristics /516 Similarity Rules /522 Cavitation and Net Positive Suction Head /526 Pump Selection: Applications to Fluid Systems /529 Blowers and Fans /541 10.4 Positive Displacement Pumps /548 10.5 Hydraulic Turbines /552 Hydraulic Turbine Theory /552 Performance Characteristics for Hydraulic Turbines /554 Sizing Hydraulic Turbines for Fluid Systems /558 10.6 Propellers and Wind-Power Machines /562 Propellers /563 Wind-Power Machines /571 10.7 Compressible Flow Turbomachines /581 Application of the Energy Equation to a Compressible Flow Machine /581 Compressors /582 Compressible-Flow Turbines /586 10.8 Summary and Useful Equations /586 References /589 Problems /591 CHAPTER 11 FLOW IN OPEN CHANNELS /600 11.1 Basic Concepts and Definitions /603 Simplifying Assumptions /604 Channel Geometry /605 Speed of Surface Waves and the Froude Number /606 11.2 Energy Equation for Open-Channel Flows /610 Specific Energy /613 Critical Depth: Minimum Specific Energy /616 11.3 Localized Effect of Area Change (Frictionless Flow) /619 Flow over a Bump /620 11.4 The Hydraulic Jump /625 Depth Increase Across a Hydraulic Jump /627 Head Loss Across a Hydraulic Jump /628 11.5 Steady Uniform Flow /631 The Manning Equation for Uniform Flow /633 Energy Equation for Uniform Flow /639 Optimum Channel Cross Section /640 11.6 Flow with Gradually Varying Depth /641 Calculation of Surface Profiles /643 11.7 Discharge Measurement Using Weirs /646 Suppressed Rectangular Weir /646 Contracted Rectangular Weirs /647 Triangular Weir /648 Broad-Crested Weir /648 11.8 Summary and Useful Equations /650 References /652 Problems /653 CHAPTER 12 INTRODUCTION TO COMPRESSIBLE FLOW /657 12.1 Review of Thermodynamics /659 12.2 Propagation of Sound Waves /665 Speed of Sound /665 Types of Flow—The Mach Cone /670 12.3 Reference State: Local Isentropic Stagnation Properties /673 Local Isentropic Stagnation Properties for the Flow of an Ideal Gas /674 www.5 Summary and Useful Equations /681 References /683 Problems /683 CHAPTER 13 COMPRESSIBLE FLOW /689 13.1 Basic Equations for One-Dimensional Compressible Flow /691 13.