Classification of Fluid Flow
Density
Incompressible
Density doesn’t vary significantly.
Examples:
- Pipe and channel flows of liquids
- Gas flows in pipes
Compressible
Density varies significantly.
Examples:
- Pressure surges in pipes
Viscosity
Non-viscous
Fluid doesn’t show any resistance to the flow.
Viscous
Fluid shows any resistance to the flow.
- Newtonian:
Examples: Water - Non-newtonian:
Examples: Paints, Clay, Plastics
Variation of parameters
The parameters:
- Velocity
- Pressure
- Flow rate
Temporal Variation
The variation of the parameters with time.
Steady
Parameters don’t change with time at a point.
Unsteady
Parameters changes with time at a point.
Spatial Variation
The variation of the parameters with coordinates.
Uniform
Parameters don’t change with the location of the point.
Non-uniform
Parameters change with the location of the point.
Dimensional
If a variation of flow parameter in a certain direction can be neglected, that can reduce the calculations.
Nature of movement
Laminar
Fluid particles move in a orderly fashion.
Turbulent
Fluid particles move disorderly.
Rotation of particles
Rotational
Fluid particles rotate while moving. Usually due to shear forces. Flow of real fluids.
Non-rotational
Fluid particles don’t rotate while moving. Only when there are no shear forces. Flow of frictionless forces.