This document discusses viscous flow between parallel plates and various methods for measuring fluid viscosity. It describes the velocity distribution and shear stress for flow between parallel plates. It also discusses journal bearings, footstep bearings, and dashpots, analyzing the torque, power absorbed, and piston motion for each. Finally, it summarizes several methods for measuring viscosity, including the capillary tube method, rotating cylinder method, falling sphere method, and orifice tube viscometer.

1. Subject Code : 130101

2. Topic:
Viscous Flow
3rd
semester
B.E. Mechanical
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3. Flow of Viscous fluid between two Parallel
Plate.
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4.  For Steady & Uniform Flow acceleration is Zero.
 Net Force F = mass X Acceleration = 0
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5. Velocity Distribustion
 Shear Stress
 Put Value of shear stress in eq.
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6. CCET, WADHWAN

7. CCET, WADHWAN

8. Ratio of Maximum Velocity to Avg. Velocity
 Velocity Will be maximum at Y = t/2,
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9.  Integrating from 0 to t
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10.  Ratio of maximum Velocity to Avg. velocity
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11. Drop of Pressure Head for a given Length
 Avg. Velocity is given by
 Integrate With respect to X
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13. Shear Stress Distribution
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14. Journal Bearing
 A journal Bearing is a hollow cylindrical enclosing a
solid shaft that rotates about its axis at radial
speed.
 The gap between bearing and shaft is filled by
viscous oil and it will be consider at rest.
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15.  Consider a Shaft Diameter = D
 Length of shaft = L
 Clearance = t
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16.  Torque required to overcome viscous resistance
 Power Absorbed
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17. Foot Step Bearing
 When a vertical shaft is required to rotate inside a
fixed bearing, the viscous oil is placed between the
top of the bearing and bottom of the shaft.
 R = Radius of shaft
 N = Speed of the shaft
 X= Clearance between
Bearing shaft
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20.  Power absorbed to overcoming the shear
resistance
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21. Movement of Piston in Dashpot
 Dashpot is a device used for damping vibration of
machine by using high viscous fluid.
 It consist of a piston which moves in a cylinder.
 Diameter of cylinder is slightly greater the piston.
 Piston is connected to the machine element whose
movement is to be restrained.
 Consider a piston moving in a vertical dashpot
containing oil as shown in fig.
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23.  The oil flow through the clearance behaves as laminar
flow between parallel plates.
 Pressure difference for parallel plate is given by
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24.  Eq. Shows that piston velocity is directly proportional to
load acting on the piston.
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25. Methods of Measurement of Viscosity
 The device use for measurement of viscosity
are known as Viscometer.
 Various Methods for Measurement of Viscosity
I. Capillary tube Method
II. Rotating cylinder Method
III. Falling Sphere Method
IV. Orifice tube Viscometer
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26. Capillary tube Method
 This method use Hagen- Poiseuille eq. for laminar
flow through circular pipe.
 A tank in which the liquid is filled whose viscosity
is to be determined.
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29. Rotating Cylinder Method
 Rotating Cylinder Method of measuring viscosity is
based on Newton’s law of Viscosity.
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30. CCET, WADHWAN
Which is final equation.

31. Thank you….