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Fundamentals of Fluid
Mechanics
Lecturer: 1
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Ch.E-203 (Fundamentals of Fluid Mechanics)
Syllabus:
Introduction and importance of fluid mechanics; Description of Fluids; Types of
fluids and Classification of fluid flows; Compressible vs Incompressible fluids;Steady and Unsteady fluid flows; Properties of fluids; Basic Equations of fluid flow;Flow of incompressible fluids in pipes; Laminar and Turbulent flow in closedchannels; Processes of Compressible Fluid Flows; Flow through variable areaconduits; Boundry Layer Concept; Prandtl's Boundary Layers Equatons; TurbulentBoundary Layers; Dimensional Analysis.
Text and Reference Books:
1. McCabe Warren L., Smith Julian C., Harriott peter Unit Operations of ChemicalEngineering 6thEd. 2001. McGraw Hill Inc.
2. Coulson J.M., Richardson J.F. Chemical Engineering Vol-I, 1999. Butterworth,Elsevier.
3. White, F.M. Fluid Mechanics, 4thEdition, McGraw-Hill. 1999.4. Holland, F.A. Bragg, R. Fluid flow for Chemical Engineers, 2ndEdition, Butterworth
& Heinemann. 1995.
5. Noel-de-Nevers Fluid Mechanics for Chemical Engineers McGraw-Hill
6. Fundamental of Fluid Mechanics, 6th Edition.
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HISTORY
FACES OF FLUID MECHANICS
Archimedes(C. 287-212 BC)
Newton(1642-1727)
Leibniz(1646-1716)
Euler(1707-1783)
Navier(1785-1836)
Stokes
(1819-1903)
Reynolds
(1842-1912)
Prandtl
(1875-1953)
Bernoulli(1667-1748)
Taylor
(1886-1975)
http://www-gap.dcs.st-and.ac.uk/~history/PictDisplay/Taylor_Geoffrey.html8/9/2019 Unit Operation ANd Process
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Fluid Mechanics
What is mechanics?
Deals with the motion of bodies
What is fluid mechanics?
Study of the behaviour of gases and liquids.
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Importance of Fluid Mechanics?
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Classification of Fluid Mechanics
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Classification of Fluid Mechanics
Fluid statics
Fluid kinematics
Fluid dynamics
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Fluid Statics
Mechanics of fluids
at rest
in equilibrium
no shear stress
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Fluid Kinematics
Concerns with the motion of the fluids
Direction
Velocities
Streamlines
but
Without reference to forces which cause the motion
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Fluid Dynamics
Mecahnics of fluid
In motion
Fluids have some shear stress
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FluidAnything which can flow.
Any material or a substance that changes its shape or direction uniformly
on applying an external force to it.
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Classification of Fluids
Ideal fluids
Real fluids
Compressible fluids
Incompressible fluids
Newtonian fluids
Non-Newtonian fluids
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Newtons Law of Viscosity
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Shear stressShear rate
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Flow of fluid
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Velocity = max
Velocity gradient = 0
Shear stress = 0
Shear stress = max
Velocity = 0
Velocity gradient = max
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NEWTONIAN
Water
Most salt solutions in waterLight suspensions of dye
High-viscosity fuels
Gasoline
Kerosene
Most motor oils and mineral oils
PSEUDOPLASTIC
Sewage sludge
Paper pulp
Grease
SoapPaint
Printer's ink
Starch
Latex solutions
Most emulsions
DILATANT
Feldspar
Mica
ClayBeach sand
Starch in water
Bingham plastic
clay suspensions,
drilling mudtoothpaste
Mayonnaise
chocolate
mustard
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Reynolds NumberChange in flow depends upon four parameters
Diameter of tube through which liquid flows (D)
Density of the liquid (rho)
Average velocity of the liquid flowing (u)
Viscosity of the liquid (u)
Reynolds combine these four quantities in one dimensionless group.
The flow is
laminar when Re < 2300
transient when 2300 < Re < 4000
turbulent when 4000 < Re
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fluid flows in parallel layers
no disruption between the layers
No lateral mixing