Relationships between turbulent intensities in turbulent pipe and channel flows
Abstract
Turbulent isothermal flow in the inlet and in the fully developed regions of smooth pipes and channels were studied in the range of y/d 0.11, where y is distance from the wall and d is pipe radius, for a wide Reynolds number range. In each set of data considered, it is found that any two components of turbulence intensity are very nearly linearly related. This result corroborates the Prandtl mixing length theory, which assumes that the turbulent fluctuations are proportional to the product of a local mixing length and a velocity gradient, so that the turbulence fluctuation components should be directly proportional to each other. The approximate empirical linear relationships for developing and fully developed pipe and channel flows are given along with the Reynolds number ranges of validity.
 Publication:

Aeronautical Journal
 Pub Date:
 April 1979
 Bibcode:
 1979AeJ....83..159A
 Keywords:

 Channel Flow;
 Isothermal Flow;
 Mixing Length Flow Theory;
 Pipe Flow;
 Turbulent Flow;
 Inlet Flow;
 Reynolds Number;
 Unsteady Flow;
 Velocity Distribution;
 Fluid Mechanics and Heat Transfer