Flow Velocity Profiles

Not all the fluid particles travel at similar velocity inside a pipe. The shape of the velocity curve (i.e., the velocity profile across any given part of the pipe) based upon whether the flow is laminar or turbulent. When the flow in a pipe is laminar, the velocity division at a cross section will be parabolic in shape with the highest velocity at the center being around twice the average velocity in the pipe. In turbulent flow, a pretty flat velocity division exists across the section of pipe, with the outcome which the whole fluid flows at a specified single value. The figure shown below helps to illustrate the above concept. The velocity of the fluid in contact with the pipe wall is necessarily zero and raises the further away from the wall.

Figure: Laminar and Turbulent Flow Velocity Profiles

Note the figure shown above that the velocity profile based upon the surface condition of the pipe wall. The smoother wall outcomes in a more uniform velocity profile than a rough pipe wall.