Fluid Mechanics
Course Objective:
A proper understanding of fluid mechanics is extremely important in many areas of civil engineering. This course has been designed to provide basic knowledge of fluid mechanics to the students of civil engineering so that it would be helpful them to understand the basic phenomena of this science. This course shall be considered as an introduction: common for all civil engineering faculties of Tribhuvan University in the second year first part of undergraduate.
 Fluid and its physical properties (3 hours)
 Basic concept and definition of fluid. Application in civil engineering
 Shear stress in a moving fluid, Difference between solids and fluids
 Concept of control volume and continuum in fluid mechanics
 Mass density, specific weight, specific gravity, specific volume, viscosity, compressibility, capillarity, surface tension, cavitation and vapour pressure (relations, their dimension, units as well as values for different materials).
 Newton’s law of viscosity causes of viscosity in liquid and gases.
 Variation of viscosity with temperature for different fluids
 Different methods for finding viscosity of fluids like viscometer etc.
 Ideal and Real fluid, Newtonian and non Newtonian, compressible and incompressible fluid with examples
 Pressure and Head (4 hours)
 Introduction, application in civil engineering. Concept about the absolute and relative equilibrium.
 Atmospheric, gauge and absolute pressure
 Hydrostatics law of pressure distribution (pressure depth relationship)
 Pascal's law
 Measurement of pressure, simple manometer as piezometer, Utube manometer, single column vertical and inclined manometers, differential manometer, inverted Utube differential manometer, bourden gauge
 Hydrostatics (10 hours)
 Pressure force and centre of pressure on submerged bodies (plane and curve Surfaces)
 Computation of pressure forces on gates (plane and curve), dams, retainingstructures and other hydraulic structures, pressure diagrams
 Buoyancy, flotation concept, thrust on submerged and floating bodies, hydrometer
 The stability of floating and submerged bodies.
 Metacentre, determination of metacentric height.
 Liquid in relative equilibrium (pressure variation in the case of uniform linear and radial acceleration)
 Computer programme coding for simple problems
 Hydrokinematics (4 hours)
 Lagragian and Eulerain approaches of describing fluid flow
 One, two and three dimensional of flow
 Classification of fluid motion (uniform and nonuniform, steady and unsteady, laminar and turbulent flows)
 Rotational and Irrotational motion, stream function and potential function.
 Description of streamline, streak line, path line and stream tube and their drawing procedures
 Conservation principle of mass and continuity equation in Cartesian and cylindrical polar coordinates (one , two and three dimensional)
 Hydrodynamics (2 hours)
 Forces acting on a fluid in motion (gravitational, pressure, viscous, turbulent, surface tension, and compression forces)
 Reynolds's, Euler's and NavierStoke's equation of motions
 Development of the Euler's Equation of motion
 Bernoulli's equation and its physical meaning
 Flow measurement (7 hours)
 Venturimeter, orifice meter nozzle meter and Pitot tube
 Flow through orifice (small orifice, large orifice, partially submerged orifice as well as submerged orifice)
 Different hydraulic coefficients Cv, Cc and Cd) and their determination
 Notches and Weir (classification, discharge through rectangular, triangular trapezoidal , and Cipoletti notches, Sharp crested weir, narrow crested weir, broad crested as well as ogee shaped weirs)
 Emptying and filling of reservoirs without inflow (cylindrical, hemispherical and conical). Emptying and filling of reservoir with inflow (cylindrical case).
 Computer programme coding for simple problems
 Momentum principle and flow analysis (6 hours)
 Momentum principle and equations
 Application of equation of calculate forces (pipe in bends, enlargements and reducer)
 Forces exerted by the jet on stationary and moving vanes of different shapes
 Concept of angular momentum with examples.
 Boundary Layer theory (3 hours)
 Boundary layer concept and definition.
 Boundary layer concept along a thin plate (laminar zone, turbulent zone, transition zone as well as laminar sub layer)
 Application of this concept (hydraulically smooth and rough boundary)
 Boundary layer thickness (Boundary layer thickness, momentum thickness, and is placement thickness)
 Flow past through submerged bodies (3 hours)
 Introduction to the drag and lift forces acting on a body
 Expression for drag and lift forces
 Pressure and friction drag; drag coefficients
 Drag on a flat plate, cylinder and sphere
 Concept of aerofoil.
 Similitude and physical modeling (3 hours)
 Introduction to dimensional analysis (physical quantities and their dimensions)
 Methods of dimensional analysis (Rayleigh and Buckingham theorem)
 Similitude, laws of similarity, distorted and undistorted model Physical model and modeling criteria (Reynolds, Froude, Euler, Weber and Mach's model laws with some examples.)
Practical:
The following exercises will be performed in this course. These are:
 Hydrostatic force on submerged body
 Stability of a floating body
 Verification of Bernoulli’s equation
 Impact of jet
 Flow through edged orifice
 Flow over broadcrested weir
Tutorials:
There shall be related tutorials exercised in class and given as regular homework exercises. Tutorials can be as following for each specified chapters.
 Physical Properties of Fluids (2 hours)
 Practical examples, numerical examples
 Pressure and Head (3 hours)
 Practical examples, numerical examples and derivation type questions
 Hydrostatics (6 hours)
 There will be tutorial for each subsection
 Use of computer programme (studied in I/I) for solving exercises
 Hydrokinematics (2 hours)
 Practical examples, numerical examples and derivation type questions
 Hydrodynamics (3 hours)
 Practical examples, numerical examples and derivation type questions
 Flow measurements (4 hours)
 Practical examples, numerical examples and derivation type questions
 There will be tutorial for each subsection
 Use of computer programme (studied in I/I) to solve some problems
 Momentum principle and flow analysis (3 hours)
 Practical examples, numerical examples and derivation type questions
 There will be tutorial for each subsection
 Use of computer programme (studied in I/I) to solve some problems
 Flow past submerged bodies (2 hours)
 Practical examples, numerical examples and derivation type questions
 Boundary layer theory (2 hours)
 Practical examples, numerical examples and derivation type questions
 Similitude and physical modeling (2 hours)
 Practical examples, numerical examples and derivation type questions
References:
 “Fluid Mechanics for Civil Engineers”, Webber, N.B. 1995, Chapman and Hall.
 Victor and street, “Elementary fluid mechanics”, sixth edition, John wiley and sons inc. 605, third avenue, Newyork
 D.S. Kumar “Fluid Mechanics and Fluid power Engineering” S.K. Kataria and Sons, sixth edition, 2005
 K. L. Kumar “Engineering Fluid Mechanics”, , Eurasia Publishing house (P) Ltd. Ram Nagar New Delhi, 2000.
 Hydraulics fluid mechanics and fluid machines, S Ramamrutham. Dhanpat Rai Publishing Company (P) Ltd. New Delhi Seventh Edition 2006
 Fundamentals of Fluid Mechanics, D. P.Sangroula, Nepal Printing Support, Anamnager, Kathmandu, 2008
Evaluation Scheme:
The question will cover all the chapters of the syllabus. The evaluation scheme will be as indicated in the table below:
Chapters 
Hours 
Marks Distribution* 
1 
3 
6 
2 
4 
6 
3 
10 
15 
4 
4 
6 
5 
2 
4 
6 
7 
12 
7 
6 
8 
8 
3 
7 
9 
3 
8 
10 
3 
8 
Total 
45 
80 
*Note: There may be minor deviation in marks distribution
