H. W. Townes


This paper describes the results of an experimental and analytical study of turbulent flow in rough pipes. Appropriate forms of mean and turbulence energy balances were developed by including mean radial and angular velocity components and using a spatial averaging technique in addition to the normal time average. An experimental program was then devised for determining the various terms in these equations. The quantities measured included the longitudinal mean velocity, rms values of fluctuating velocity components in the 3 coordinate directions, second and third order correlations between fluctuating velocities, and various components of the dissipation function. All of these quantities were determined for three degrees of roughness at a single Reynolds number. Calculation of the various energy quantities from the measured parameters indicated some very definite roughness effects. The most evident reasons for such effects include the fact that a portion of the available mean energy is converted to roughness energy for flow in a rough pipe and the fact that the roughness elements occupy the region where turbulence is produced in the smooth pipe.

Meeting Name

Symposium on Turbulence in Liquids (1971: Oct. 4-6, Rolla, MO)


Chemical and Biochemical Engineering

Document Type

Article - Conference proceedings

Presentation Type

Contributed Paper


Pressure Fluctuations

Document Version

Final Version

File Type





© 1972 University of Missouri--Rolla, All rights reserved.