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GATE Water Resource Engineering Book

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WATER RESOURCE ENGINEERING

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Civil Engineering

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Syllabus Water Resource Engg

Syllabus for

Water Resource Engineering

Fluid Mechanics and Hydraulics

Properties of fluids, principle of conservation of mass, momentum, energy and corresponding equations, potential flow, applications of momentum and Bernoulli's equation, laminar and turbulent flow, flow in pipes, pipe networks. Concept of boundary layer and its growth. Uniform flow, critical flow and gradually varied flow in channels, specific energy concept, hydraulic jump. Forces on immersed bodies, flow measurements in channels, tanks and pipes. Dimensional analysis and hydraulic modeling. Kinematics of flow, velocity triangles and specific speed of pumps and turbines.

Hydrology

Hydrologic cycle, rainfall, evaporation, infiltration, stage discharge relationships, unit hydrographs, flood estimation, reservoir capacity, reservoir and channel routing. Well hydraulics.

Irrigation

Duty, delta, estimation of evapo-transpiration. Crop water requirements. Design of: lined and unlined canals, waterways, head works, gravity dams and spillways. Design of weirs on permeable foundation. Types of irrigation system, irrigation methods. Water logging and drainage, sodic soils.

Analysis of GATE Papers

(Water Resource Engineering)

Year Percentage of marks Overall Percentage

2013 15.00 18.99% 2012 14.00 2011 14.00 2010 12.00 2009 14.00 2008 19.33 2007 20.67 2006 21.33 2005 24.66 2004 31.33 2003 22.60

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Contents Water Resource Engg

C O N T E N T S

Chapter

Page No

#1. Introduction

1–12

Branches of Fluid Mechanics

1– 3

Compressible and Incompressible Fluids

3

Moving and Stationary Parallel Plates

4 – 7

Summary of Main Points

7 – 8

Solved Examples

9 – 10

Assignment

11

Answer Keys

12

Explanations

12

#2. Pressure and It’s Measurement

13 – 22

Tensors

13 – 15

Measurement of Pressure

15

Summary of Main Points

16 – 17

Solved Examples

18 – 20

Assignment

21

Answer Keys

22

Explanations

22

#3. Hydrostatic Forces on Plane Surfaces

23–35

Parallel Axis Theorem

23 – 24

Force on a Vertical Plane Area

24 – 26

Summary of Main Points

26 – 27

Solved Examples

28 – 32

Assignment

33 – 34

Answer Keys

35

Explanations

35

#4. Floatation and Stability

36 – 44

Hydrostatic Terminology

36 – 38

Stability

38 – 40

Summary of Main Points

41 – 42

Solved Examples

42 – 44

#5. Relative Equilibrium of Fluids

45 – 55

Liquid Mass Subjected to Uniform Linear Horizontal

Acceleration

45 – 46

Acceleration of a Fluid Mass Along a Slope

47 – 51

Free Vortex

51 – 52

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Contents Water Resource Engg

Assignment

54

Answer Keys

55

Explanations

55

#6. Kinematics of Flow

56 – 72

Kinematics

56 – 57

Compressible Flow & Incompressible Flow

57 – 58

Flow Visualization

58 – 63

Flow Net Theory

63

Summary of Main Points

64 – 67

Solved Examples

67 – 70

Assignment

71

Answer Keys

72

Explanations

72

#7. Fluid Dynamics

73–89

Equation of Motion and Energy Equation

73 – 75

The Venturimeter

75 – 76

The Orifice Plate

76 – 79

Summary of Main Points

80 – 83

Solved Examples

83 – 87

Assignment

88

Answer Keys

89

Explanations

89

#8. Flow Through Pipes

90 – 100

Major Losses

90 – 91

Applying Bernoulli’s Equation

91 – 93

Hydraulic Gradient and Total Energy Line

93 – 95

Summary of Main Points

96 – 100

#9. Impulse Momentum Equation and Its Application

101–105

The Momentum Equation

101 –102

Free Liquid Jets

103

Summary of Main Points

104 – 105

#10. Flow Through Orifices and Mouth Pieces

106–122

Sharp Edged Orifice Discharging Free Jet

106 – 108

Experimental Determination of the Coefficients for an Orifice

108 – 112

Flow Through Submerged (or drowned) Orifice

113

Summary of Main Points

114 – 117

Assignment

118 – 120

Answer Keys

121

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Contents Water Resource Engg

#11. Weirs and Notches

123–132

Weirs and Notches

123 – 125

Flow over a Trapezoidal Weirs or Notch

125 – 126

Summary of Main Points

126 – 130

Assignment

131

Answer Keys

132

Explanations

132

#12. Boundary Layer Flow

133 – 142

Boundary Layer Flow

133 –135

Boundary Conditions for Velocity Profiles

135 – 136

Turbulent Boundary Layer

136 – 137

Summary of Main Points

138 – 140

Assignment

141

Answer Keys

142

Explanations

142

#13. Viscous Flow

143–159

Flow of Viscous Fluid Through Circular Pipe

143 – 145

Flow of Viscous Fluid Between Two Parallel Plates

146 – 151

Methods of Determination of Co – Efficient of Viscosity

151 – 152

Summary of Main Points

152 – 159

#14. Hydraulics & Hydraulic Machinery

160 – 200

Flow in Open Channels

160 – 165

Measuring Flumes

165 – 168

Bresse’s Method

168 – 173

Curved Vanes on Wheel

173 – 187

Reciprocating Pumps

187 –188

Summary of Main Points

189 – 200

#15. Dimensional Analysis

201 – 208

Dimensional Analysis

201 – 203

Model Laws or Similarity Law

203 – 206

Summary of Main Points

206 – 208

#16. Irrigation

209 – 216

Introduction

209 – 210

Flow Irrigation

210 – 213

Limitations

213

Solved Examples

214

Assignment

215

Answer Keys

216

Explanations

216

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Contents Water Resource Engg

#17. Water Requirements of Crops

217–221

Definition

217 – 218

Duty at Various Places

218 – 220

Optimum Utilization of Irrigation Water

220 – 221

#18. Soil Moisture Irrigation Relationship

222–228

Field Capacity

222 – 223

Solved Examples

224 – 228

#19. Sediment Transport and Design of Irrigation Channels

229–266

Sediment Transport and Design of Irrigation Channels

229 – 230

Mechanics of Sediment Transport

231 – 234

Water Logging Control

234 – 237

Suitability

237

Design of Channels

238 – 248

Economical & Physical Justification for Canal

249 – 250

Causes of Failure of Weir on Permeable Foundation

250 – 263

Assignment

264 – 265

Answer Keys

266

Explanations

266

#20. Hydrology

267 - 326

Introduction to Hydrology

267 – 271

Precipitation

271 – 281

Evaporation and Infiltration

281 – 295

Stage Discharge Relationships

295 – 300

hydrograph and Runoff

301 – 310

Floods Estimation

310 – 314

Well Hydraulics

314 – 320

Assignment

321 – 324

Answer Keys

325

Explanations

325 – 326

Module Test

327 - 335

Test Questions

327 – 333

Answer Keys

334

Explanations

334 – 335

Reference Books

336

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Chapter 1 Water Resource Engg

Chapter-1

Introduction

Branches of Fluid Mechanics

1. Fluid statics:- deals with fluid at rest

2. Fluid kinematics:- deals with velocities & streamlines

3. Fluid dynamics:- That deals with velocity & accelerations and hence with forces.

Classical Hydrodynamics:- It is mathematical subject that deals with ideal frictionless fluids. Classical Hydraulics:- Deals with Reals fluid.

Fluid Mechanics = Classical Hydrodynamics + Classical Hydraulics. Common Temperature Scales

1. = 2. 273 C

 For most gases the molecular density is 2.7 x 1025 molecules per m3. Continuum Flow

Two factors which are important in determining the validity of continuum model. 1. The distance between molecules.

This distance is evidently not the same for all the molecules in the gas at anyone time. Therefore an average distance called the molecular mean free path.

The mean free path of atmospheric air is 50 – 70 mm. 2. Elapsed time between collisions.

 A dimensionless parameter, the Knudsen number Kn = = Molecular mean free path.

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Chapter 1 Water Resource Engg

1) Continuum ( n ≤ 0.01) – no slip condition. It is condition of zero velocity at solid boundary.

2) Slip flow (0.01 < Kn ≤ 0.1) – These conditions provide for a finite velocity and a temperature jump at a solid boundary.

3) Transition flow (0.10 < n ≤ 10) – The kinetic theory of gases must be employed to adequately describes this flow.

4) Free molecular flow (Kn > 10) molecular interaction can be neglected.

 Homogeneity – Identical in all points. Isotropy – Identical in all directions. 1. 2. Terms a. Density (ρ) = = Unit (Kg/m3, slug/ft3). b. Specific weight (γ). γ units ( m 1 ft⁄ pcf). γ eg c. Specific volume ∀ ∀ unit (m ⁄ g ft ⁄slug). d. Specific gravity (S) Solid Stress continuous deformation Solid Stress Fixed deformation

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Chapter 1 Water Resource Engg

S =

It is the ratio of specific weight (or density) of a fluid at actual conditions to the specific weight (or density) of pure water at standard conditions (101 kN/m2, 200C).

 Specific weight Of liquids.

1. Varies only slightly with pressure. 2. May vary considerably with temperature. Compressible and Incompressible Fluids

Compressible – Variable density. Incompressible – Constant density.

Ideal Fluids 1. No friction

2. Inviscid (zero viscosity) fluid.

3. Internal forces at any section within are normal (pressure forces). 4. Ideal fluid & ideal gas or perfect gas both are different.

Real Fluids

1. Tangential or shearing forces always develop where there is motion relative to solid body. Thus, fluid friction is created.

2. Shear forces opposes motion of one particle past another. 3. Friction forces gives rise to a fluid property called viscosity. Variation of Viscosity with Temperature

Liquids:- Viscosity decreases as temperature increases. Gases:- Viscosity increases as temperature increases

Temperature Viscosity

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Chapter 1 Water Resource Engg

Moving and Stationary Parallel Plates

Fluid particles adhere to walls: No slip conditions

Velocity: zero at (1) & U at (2) → velocity profile. For small U γ and no net flow → linear velocity experiment show that F ~

ow newton’s eqn. τ ( ) ∝ τ μ μ

here μ coefficient of viscosity a solute viscosity dynamic viscosity or simply viscosity.

Based on Property of Viscosity, Fluids May Be Classified (i) Ideal Fluid  μ 0 o shear stress exists.

(ii) Real Fluid – Shear stresses are induced when fluid is in motion, which possesses viscosity. (iii) Newtonian Fluid:- which follows the Newton law (τ ∝

). Eg. Air, water.

(iv) Non Newtonian Fluids:- It is a fluid in which shear stress is not proportional to velocity gradient

Ex:- paints printer’s ink gel emulsions.

Ideal fluid Shear

stress Pseudo plastic Dilatant (Velocity gradient) du dy μ 1 yield stress ∴ Rheological diagram Moving plate F, U (2) y

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References

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