Understanding Absolute Viscosity - shearing stress

AI Thread Summary
Absolute viscosity measures a fluid's internal resistance, defined as the tangential force per unit area needed to move one plane relative to another at unit velocity. Shearing stress, applicable to Newtonian fluids, is the sideways force per unit area required to move fluid layers and can be measured by dividing the force applied by the area of the plates. Kinematic viscosity is derived from absolute viscosity divided by fluid density, with absolute viscosity expressed in gm/cm-sec and kinematic viscosity in cm²/sec. The discussion also raises questions about calculating shearing force and the physical significance of absolute and kinematic viscosity. Understanding these concepts is essential for analyzing fluid dynamics in various applications.
Chadi B Ghaith
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Understanding Absolute Viscosity - shearing stress
Hi everyone,
I have found information about Absolute viscosity:

Coefficient of absolute viscosity is a measure of internal resistance. Dynamic (absolute) viscosity is the tangential force per unit area required to move one horizontal plane with respect to an other plane at an unit velocity when maintaining an unit distance apart in the fluid.

The shearing stress between the layers of a non turbulent fluid moving in straight parallel lines can be defined for a Newtonian fluid. Now my question is what is shearing stress and how to measure it? What is the relationship between Absolute and Kinematic Viscosity?
which units I can use for Absolute and Kinematic Viscosity?
 
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Chadi B Ghaith said:
Understanding Absolute Viscosity - shearing stress
Hi everyone,
I have found information about Absolute viscosity:

Coefficient of absolute viscosity is a measure of internal resistance. Dynamic (absolute) viscosity is the tangential force per unit area required to move one horizontal plane with respect to an other plane at an unit velocity when maintaining an unit distance apart in the fluid.

The shearing stress between the layers of a non turbulent fluid moving in straight parallel lines can be defined for a Newtonian fluid. Now my question is what is shearing stress and how to measure it?
Shearing stress is the sideways force per unit area that you have to apply to the plates. You measure the force required, and divide by the plate area.

What is the relationship between Absolute and Kinematic Viscosity?
Kinematic viscosity is equal to absolute viscosity divided by density
which units I can use for Absolute and Kinematic Viscosity?

Absolute viscosity: ##\frac{gm}{cm-sec}##

Kinematic viscosity: ##\frac{cm^2}{sec}##
 
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Chestermiller said:
Shearing stress is the sideways force per unit area that you have to apply to the plates. You measure the force required, and divide by the plate area.Kinematic viscosity is equal to absolute viscosity divided by densityAbsolute viscosity: ##\frac{gm}{cm-sec}##

Kinematic viscosity: ##\frac{cm^2}{sec}##
Thanks Chestermiller.

But I have another questions regarding shearing force & viscosity,

1) A fluid is flowing between two layers. Calculate the shearing force if the shear velocity is 0.25 m/s and has length 2 m and dynamic viscosity is 2Ns/m$^2$.

2) What's the physical meaning of these two viscosity ?
 
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Chadi B Ghaith said:
Thanks Chestermiller.

But I have another questions regarding shearing force & viscosity,

1) A fluid is flowing between two layers. Calculate the shearing force if the shear velocity is 0.25 m/s and has length 2 m and dynamic viscosity is 2Ns/m$^2$.

2) What's the physical meaning of these two viscosity ?
I don't see any attempt on your part to solve Problem 1. For Item 2, what does your textbook say?
 
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