The relative velocities of a fluid as it moves through a pipe, the velocity at the center being greater than the velocity at the pipe wall. Laminar flow is characterized by large differences in velocity along the profile, while turbulent flow exhibits a “flatter” profile with more consistent velocity across the pipe diameter. Relevant to insertiontype flowmeters such as Pitot tubes where the flowing velocity is sampled at only one point in the flowstream.
Then dp transmitter was not detecting actual flow, velocity at the centre was not equal to suface
Yes, that’s why there always be little bit error of flow reading, which we state in-terms of accuracy of the measurement.