Uniform & Non Uniform Flow Types

Hello all

I am trying to understand the difference between different types of fluid flow specifically Uniform and Non Uniform flow.

My understanding is that uniform flow can be defined as "fluid flow in which the fluid characteristics such as velocity, pressure, density at a point or area (depending on your control volume) does not change with respect to the cross section / area / length."

My understanding of non uniform flow is "fluid flow in which the fluid characteristics such as velocity, pressure, density at a point or area (depending on your control volume) changes with respect to the cross section / area / length."

With this definition in mind if i had a pipe with a constant cross section with fluid flowing through it then if the fluids properties such as velocity, pressure density etc did NOT change as the fluid traveled through the pipe then the fluids flow can be defined as uniform.

Similarly if I had a pipe where the cross section varied along the pipe then as the fluid flowed through the pipe its properties such as velocity, pressure density etc did change then the fluids flow can be defined as non uniform.

If this is correct then what if i had a situation where i had a constant cross section pipe and fluid traveled through it and the fluids properties such as density, velocity, pressure etc did change then would this is defined as uniform or non uniform flow?

You thoughts?

Thank you.

Uniform flow
Flow of a fluid in which each particle moves along its line of flow with constant speed and in which the cross section of each stream tube remains unchanged.


Non-uniform flow
Flow is said to be non-uniform, when there is a change in velocity of the flow at different points in a flowing fluid, for a given time. For example, the flow of liquids under pressure through long pipelines of varying diameter is referred to as non-uniform flow.

when the size and shape of cross section are constant along the length of channels under consideration, the flow is said to be uniform. A non-uniform flow is one in which velocity is not constant at a given instant

In uniform flow if the velocity at a given instant of time is same in both magnitude and direction at all points in the flow, the flow is said to be uniform flow. When the velocity changes from point to point in a flow at any given instant of time, the flow is described as non-uniform flow.