What is Velocity Profile?
Velocity profile is how flow velocity varies across the pipe, from near zero at the wall to a maximum near the centre.
Velocity Profile Explained
Fluid sticks to the pipe wall and moves fastest near the middle. The shape depends on Reynolds number: parabolic in laminar flow, flatter in turbulent flow.
Fittings distort the profile, making it asymmetric or adding swirl. Meters that sample velocity along a line or at a point (ultrasonic, insertion, pitot) are most sensitive to this.
Velocity Profile: Typical Values
| Laminar | parabolic, average = ½ of centreline |
| Turbulent | flat, average about 0.8 to 0.87 of centreline |
| After a bend | skewed towards the outside of the bend |
Calculators for Velocity Profile
Frequently Asked Questions
What is Velocity Profile?
Velocity profile is how flow velocity varies across the pipe, from near zero at the wall to a maximum near the centre.
What is a fully developed profile?
One that no longer changes along the pipe. It forms after enough straight length downstream of a disturbance.
How is a distorted profile fixed?
With more straight pipe upstream of the meter, or a flow conditioner that removes swirl and flattens the profile.
Learn more on the blog
What factors affect the stability of flow meter readings?
A practical guide on instrumentationblog.in with more detail on velocity profile and how it is applied on real plants.
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