Abstract
Measurements of the cross-sectional distributions of axial turbulence intensity and time-mean velocity in hydrodynamically developed pipe flows were made by means of a hot-film anemometer. The investigation was concerned with the low Reynolds number turbulent regime, and experiments were performed for five Reynolds numbers between 3200 and 24 000. Air was the working fluid. The present measurements, taken together with those of Laufer for high Reynolds number pipe flows (up to 500 000). establish that in the near-wall region characterized by y+ up to 25, the ratio of turbulence intensity to friction velocity is independent of Reynolds number. This same relative turbulence intensity is also independent of the Reynolds number in the neighborhood of the pipe centerline. The measured time-mean velocity distributions deviate more and more from the universal u+, y+ profile with decreasing Reynolds number below 10000. which corroborates the findings of previous investigations.
Original language | English (US) |
---|---|
Pages (from-to) | 1067-1074 |
Number of pages | 8 |
Journal | International Journal of Heat and Mass Transfer |
Volume | 15 |
Issue number | 5 |
DOIs | |
State | Published - May 1972 |