CE8394 - Fluid Mechanics of Machinery As per Anna University Syllabus Content Lagrangian flow Eulerian Flow Types of Fluid Flow

1. Fluid Mechanics and Machinery
(CE 8394)
Panimalar Institute of Technology
Department of Mechanical Engineering
Flow Characteristics of Fluid
Prepared by: Mr. Amos Gamaleal David
Assistant Professor
Department of Mechanical Engineering
Panimalar Institute of Technology
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2. Text Book Credits

3. Fluid Characteristics
Two Methods are used namely
1. Lagrangian Method
2. Eulerian Method
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4. Lagrangian Method
A Single Fluid particle is taken into
consideration and it is analysed and followed
to study its properties
Properties like
Velocity, acceleration and density
Eg – Following one vehicle by another
vehicle to study its motion
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6. Eulerian Method
A particle space or region maybe selected
and fluid flows through this region. During
this time the fluid characteristics are analyzed
Eg – Traffic Police Stands on one place and
observes all the vehicles going past him.
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7. Types of Fluid flow
1. Steady and Unsteady Flow
2. Uniform and Non Uniform flow
3. Laminar and Turbulent Flow
4. Compressible and Incompressible Flow
5. Rotational and Irrotational Flow
6. One Dimensional flow, 2D flow and
3D flow
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8. Steady flow
In Steady flow, the fluid characteristics like
velocity, pressure, density, temperature etc at
any point do not change with time.
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9. Unsteady flow
In Steady flow, the fluid characteristics like
velocity, pressure, density, temperature etc
changes with respect to time
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10. Uniform Flow and Non uniform flow
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11. Laminar and Turbulent Flow
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12. How to determine whether the flow is
Laminar or Turbulent?
If Re <2000 = Laminar Flow
If Re > 4000 = Turbulent Flow
If Re in between 2000 and 4000 = Transition Flow1212

13. Laminar Flow Example
• Blood Flowing through the
arteries
• Water flowing through the
plants
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14. Laminar Flow Example
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15. Turbulent flow
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16. Turbulent Flow
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17. Turbulence in the air
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18. Compressible and Incompressible flow
Compressible Flow
The Density of the fluid changes from point to point or
Density is not constant
  Constant
Incompressible flow
The Density of the Fluid is constant for the fluid flow
 = Constant
Liquids are generally incompressible
Gases are compressible
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19. Rotational and Irrotational Flow
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20. 1D, 2D and 3D flow
1D Flow
When the velocity is a function of time and one
space coordinate only (say x direction only)
2D Flow
Velocity is a function of time and two rectangular
space coordinates (say x and y direction)
3D Flow
Velocity is a function of time and three mutually
perpendicular axes (say x, y and z direction)
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21. Types of Fluids
1. Ideal Fluid. A fluid, which is incompressible and is
having no viscosity, is known as an ideal fluid. Ideal
fluid is only an imaginary fluid as all the fluids, which
exist, have some viscosity.
2. Real fluid. A fluid, which possesses viscosity, is knownas
real fluid. All the fluids: in actual practice, are realfluids.
3. Newtonian Fluid. A real fluid, in which the shear stressis
directly, proportional to the rate of shear strain (or
velocity gradient), is known as a Newtonian fluid.
4. Non-Newtonian fluid. A real fluid, in which shear stress
is not proportional to the rate of shear strain (or velocity
gradient), known as a Non-Newtonian fluid.
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22. Types of Fluids
5. Ideal Plastic Fluid.
A fluid, in which shear
stress is more than the
yield value and shear
stress is proportional
to the rate of shear
strain (or velocity
gradient), is known as
ideal plastic fluid.
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23. Non Newtonian Fluid
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25. Flow Patterns
(a) Streamlines (b) Streaklines
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26.  Streaklines are often confused with streamlines or pathlines.
 While the three flow patterns are identical in steady flow, they
can be quite different in unsteady flow.
 The main difference is that a streamline represents an
instantaneous flow pattern at a given instant in time, while a
streakline and a pathline are flow patterns that have some age
and thus a time history associated with them.
 If the flow is steady, streamlines, pathlines, and streaklines are
identical
Flow Patterns
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27. Thank You for your
Patience and Cooperation
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