Velocity Measurement Using Pitot Tubes

Pitot tubes (and pitot static tubes) are commonly used for velocity measurement in a wide variety of flow situations due to their simple construction and low cost. Although their application is primarily meant for laminar incompressible flows at high velocities, measurements can be made in turbulent or compressible flows with some modifications.

For flows with low-level of turbulence the mean velocity is directly related to the mean pressure difference in exactly the same way as in laminar flows. It is due to the fact that the time-averaged pitot tube reading is unaffected by turbulence levels upto 10 ; this result can be seen as follows.

The instantaneous pressure difference is