## Superpipe Pitot Data

Two sets of mean velocity profiles obtained in the Superpipe facility with different diameter Pitot tubes, as reported in (1) Zagarola and Smits, *J. Fluid Mech.* **373**, 1998 and (2) McKeon, Li, Jiang, Morrison and Smits, *J. Fluid Mech.* **501**, 2004, are now available. Please click on the links given below to obtain the data files (text) for each Reynolds number. The Reynolds number is based on pipe diameter and average velocity. There are profiles at a total of 26 Reynolds numbers in the range 31 x 10^{3} to 35 x 10^{6}. The facility is described on the Superpipe facilities page under the section info. For a more complete description of the facility, data acquisition and analysis procedures, see:

Mark V. Zagarola (mvz@creare.com) , "Mean Flow Scaling of Turbulent Pipe Flow," Ph.D. Thesis, Department of Mechanical and Aerospace Engineering, Princeton University, June 1996.

Beverley J. McKeon, "High Reynolds Number Turbulent Pipe Flow", Ph.D. Thesis, Department of Mechanical and Aerospace Engineering, Princeton University, June 2003.

_{p}= 0.9 mm

*et al*data (2004). Pitot probe diameter d

_{p}= 0.3 mm (+ selected Reynolds numbers with d

_{p}= 0.5, 0.9 and 1.8 mm)

**Corrections**

*It is clear that accurate Pitot probe and static pressure tapping corrections are essential for appropriate interpretation of the Superpipe data.*

The error in static pressure measured by a finite-sized wall static tapping has a more significant effect on the mean velocity analysis than previously recognized. A new study of this error was given in:

B.J. McKeon and A.J. Smits 'Static pressure correction in high Reynolds number fully developed turbulent pipe flow ' (2002)Meas. Sci. Tech.13, 1608-1614

The displacement effect due to a finite-sized Pitot probe in free shear and in proximity to a wall was also investigated and it was shown that the wall proximity correction has a significant effect on the mean velocity profile. In its absence, data nearer the wall than 2d_{p} must be excluded.

B.J. McKeon and A.J. Smits 'Pitot probe corrections in fully developed turbulent pipe flow ' (2003)Meas. Sci. Tech.14, 1449-1458

(A brief description of the Pitot probe velocity gradient corrections recommended earlier by Zagarola are contained in the file probecor.pdf , which can be read using Acrobat Reader.)