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Sahithyan's S1
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Sahithyan's S1 — Fluid Mechanics

Classification of Fluid Flow

Density

Section titled “Density”

Incompressible

Section titled “Incompressible”

Density doesn’t vary significantly.

Examples:

  • Pipe and channel flows of liquids
  • Gas flows in pipes
∣Δρ∣ρ≪1\frac{|\Delta{\rho}|}{\rho} \ll 1

Compressible

Section titled “Compressible”

Density varies significantly.

Examples:

  • Pressure surges in pipes

Viscosity

Section titled “Viscosity”

Non-viscous

Section titled “Non-viscous”

Fluid doesn’t show any resistance to the flow.

Viscous

Section titled “Viscous”

Fluid shows any resistance to the flow.

  • Newtonian: μ is constant\mu\text{ is constant}
    Examples: Water
  • Non-newtonian: μ is not constant\mu\text{ is not constant}
    Examples: Paints, Clay, Plastics

Variation of parameters

Section titled “Variation of parameters”

The parameters:

  • Velocity VV
  • Pressure PP
  • Flow rate QQ

Temporal Variation

Section titled “Temporal Variation”

The variation of the parameters with time.

Steady

Section titled “Steady”

Parameters don’t change with time at a point. V=f(x,y,z)V=f(x,y,z).

Unsteady

Section titled “Unsteady”

Parameters changes with time at a point.

Spatial Variation

Section titled “Spatial Variation”

The variation of the parameters with coordinates.

Uniform

Section titled “Uniform”

Parameters don’t change with the location of the point. V=f(t)V=f(t).

Non-uniform

Section titled “Non-uniform”

Parameters change with the location of the point.

Dimensional

Section titled “Dimensional”

If a variation of flow parameter in a certain direction can be neglected, that can reduce the calculations.

Nature of movement

Section titled “Nature of movement”

Laminar

Section titled “Laminar”

Fluid particles move in a orderly fashion.

Turbulent

Section titled “Turbulent”

Fluid particles move disorderly.

Rotation of particles

Section titled “Rotation of particles”

Rotational

Section titled “Rotational”

Fluid particles rotate while moving. Usually due to shear forces. Flow of real fluids.

Non-rotational

Section titled “Non-rotational”

Fluid particles don’t rotate while moving. Only when there are no shear forces. Flow of frictionless forces.