Fluid Mechanics (What is Fluid?)
What is Fluid?
- A substance in a liquid or gaseous form capable of deforming continuously under the action of shear stress, however small the shear stress may be is referred to as Fluid.
Note:
In Solid, shear stress is proportional to shear strain, but in Fluid shear stress is proportional to strain rate.
Fluid Mechanics deals with the behavior of fluid at rest as well as in motion:
- Study of Fluid at Rest - Fluid Static
- Study of Fluid in motion when forces responsible for the motion are not considered- Fluid Kinematics
- Study of Fluid in motion when forces responsible for the motion are considered- Fluid Dynamics
- An ideal fluid does not have surface tension, viscosity and is incompressible in nature.
Note:
No such fluid exists in a practical situation. However, fluids like air & water have a very low value of viscosity and can be treated as ideal. It is just a theoretical conception.
No-slip condition:
- A moving fluid when comes in contact with a surface, adheres to the surface i.e. if the surface is stationary, the Fluid at the surface will also be stationary and if the surface is moving, Fluid at the surface will also move with the same velocity as that of the surface.
- The no-slip condition is valid for all Real Fluid not for Ideal Fluid.
2. Fluid Pressure and its Measurement
3. Hydrostatic Forces
4. Liquids in Relative Equilibrium
5. Buoyancy and Floatation
6. Laminar Flow7. Turbulent Flow
8. Boundary-Layer Theory
9. Pipe Flow
10. Model Analysis
11. Drag and Lift