Different Flow Types

Different Flow Types of Fluid

The Fluid is a substance which flows under the action of shear force. This flowing of fluid is categorized into different types on the following basis:

      1.       Viscous and Inviscid.

      2.       Internal, External, and Open Channel Flow.

      3.       Compressible and Incompressible.

      4.       Laminar, Turbulent and Transitional.

      5.       Natural and Forced.

      6.       Steady and Unsteady.

      7.       Uniform and Non-Uniform.

      8.       Rotational and Irrotational.  

      9.       One, Two and Three Dimensional.

      10.   Potential Flow.

Viscous and Inviscid Flow:

Viscous Flow The Type of flow in which the resistance provided by the viscosity is considered

Inviscid Flow The type of flow in which the resistance provided by the viscosity (to flow) is negligible.

Note: In real life, every fluid has some viscosity.

Internal, External, and Open Channel Flow:

Internal Flow When the fluid is moving in some pipes or tubes then it is considered as internal flow.

External Flow When the fluid is moving outside the pipe or on the surface of a body.

Open Channel Flow In this type of fluid flow with a free surface and has constant pressure on the surface.

Compressible and Incompressible Flow:

Compressible Flow The Type of flow in which the density of the fluid varies with the flow.

Incompressible Flow The type of flow in which the density does not change with the flow.

Laminar, Turbulent and Transitional Flow:

Laminar Flow The type of flow in which the layers of fluid are parallel to each other and do not mix with each other.

Turbulent Flow The type of flow in which the layers of particles are not parallel to each other and mix randomly.

Transitional Flow It is an intermediary state in which the particles move in a mixed pattern. (Laminar and turbulent) In the stage the fluid in changing from laminar to turbulent flow.

Natural and Forced Flow:

Natural Flow The Flow of a fluid due to some natural source or means. e.g.: gravity, buoyancy, etc.

Forced Flow The flow of fluid with the help of some external power is known as forced flow. e.g.: pumps or fan etc.

Steady and Unsteady Flow:

Steady Flow The flow in which characteristics of fluid (velocity, temperature, pressure, and density, etc.) do not change at a point with time.

Unsteady Flow The flow in which the characteristics of fluid changes at a point with time is known as unsteady flow.

Uniform and Non-Uniform Flow:

Uniform Flow The flow in which the fluid characteristics changes with respect of time but does not change with respect to position is known as uniform flow.

Non-Uniform Flow The flow in which fluid characteristics changes with respect to time as well as with respect to position is known as non-uniform flow.

Rotational and Irrotational Flow:

Rotational Flow In this flow, the fluid particles while flowing along streamlines also rotate about their own axis.

Irrotational Flow The flow in which particle while flowing along the streamline do not rotate about their own axis.

1D, 2D, and 3D Flow:

1D Flow In one dimensional flow, velocity is a function of time and one space co-ordinate only.

2D Flow In two-dimensional flow, velocity is a function of time and two rectangular space coordinates.

3D Flow In three-dimensional flow, velocity is a function of time and three mutually perpendicular directions.

Potential Flow:

Potential Flow The flow of ideal fluid is called potential flow. The ideal fluids have zero viscosity and negligible shear stress. In potential flow, neither circulation nor eddies can form within the stream. Friction cannot be developed in the potential flow so that there is no dissipation of mechanical energy into heat.