Mechanical Properties Of Fluids 5 L-5
Mechanical Properties of Fluids
Mechanical Properties Of Fluids 5 L-5
Bernoulli's Principle
Inner walls of the arteries are elastic in nature.
There is a plaque deposition inside of the artery.
The arteries which carry blood to the heart are called coronary arteries.
Bernoulli's principle: Kinetic head + Potentioal head + Pressure head = constant
Mechanical Properties Of Fluids 5 L-5
Viscosity
The viscosity of a fluid is a measure of its resistance to deformation at a given rate.
Ideal fluid ≡ non-viscous fluid.
v1>v2>v3>v4>v5>(=0) laminar flow
Viscous fluids
Mechanical Properties Of Fluids 5 L-5
Viscosity
The applied force depends on
(i) Surface area, A
(ii) speed, v f∝v
(iii) height, h f∝h1
f∝hAv=ηhAv
η: is called as Coefficient of viscosity
Mechanical Properties Of Fluids 5 L-5
Units of Viscosity
η=AvFh=m2Nm⋅sm.
=m2N⋅s = pascal second (Pa·s).
The SI unit of viscosity is poiseiulle (PI).
1 poise = 0.1 pascal-second.
Mechanical Properties Of Fluids 5 L-5
Viscosity of some of the Common Fluids
Fluid |
Temparature (∘C) |
η(viscosity)×10−3(Pa⋅s) |
Air |
0 |
0.0171 |
Helium |
20 |
0.0196 |
blood |
37 |
4 |
Glycerine |
20 |
1500 |
Methanol |
0 |
0.584 |
Water |
0 |
1.78 |
Water |
20 |
1.0 |
Water |
40 |
0.65 |
Mechanical Properties Of Fluids 5 L-5
Poiseuille's Law
Mechanical Properties Of Fluids 5 L-5
Example
Example:
The surface tension of a soap solution is 0.02 N/m what amount of work is requred for produsing a soap bubble of radius 0.05m ?
Solution
The work lone in making a soap bubble = Surface Tension × Total Surface Area
Surface Tension × (inner + outer) surface area
=0.03N/m×2×4π(0.05m)2
=1.884×10−3J
Mechanical Properties Of Fluids 5 L-5
Summary
- Density and specific gravity .
- Pressure.
- Different units of pressure.
- Measurement of pressure Barrometer, U tube.
- Pascal's principle.
- Equation of continuity.
- Buoyancy and Archimedes principle.
- Surface tantional and surface energy.
- Bernoulli's equation
- The viscosity
Mechanical Properties Of Fluids 5 L-5
Thank You
Mechanical Properties Of Fluids 5 L-5 Mechanical Properties of Fluids $\rightarrow$ $\rightarrow$ Mechanical Properties of Fluids $\rightarrow$ Bernoulli's Principle $\rightarrow$ Viscosity