Fluid Flow Velocity Profiles

Fluid Flow Table of Contents
Hydraulic and Pneumatic Knowledge

 Fluid Power Equipment

Fluid Flow Velocity Profiles

Not all fluid particles travel at the same velocity within a pipe. The shape of the velocity curve (the velocity profile across any given section of the pipe) depends upon whether the flow islaminar or turbulent. If the flow in a pipe is laminar, the velocity distribution at a cross sectionwill be parabolic in shape with the maximum velocity at the center being about twice the averagevelocity in the pipe. In turbulent flow, a fairly flat velocity distribution exists across the section of pipe, with the result that the entire fluid flows at a given single value. Figure 5 helps illustratethe above ideas. The velocity of the fluid in contact with the pipe wall is essentially zero andincreases the further away from the wall.

Laminar and turbulent flow velocity profiles

Note from Figure 5 that the velocity profile depends upon the surface condition of the pipe wall. A smoother wall results in a more uniform velocity profile than a rough pipe wall.