Reynolds number effects in a turbulent pipe flow for low to moderate Re

Abstract

We present in this paper high resolution, two-dimensional LDV measurements in a turbulent pipe flow of water over the Reynolds number range 5000-25000. Results for the turbulence statistics up to the fourth moment are presented, as well as power spectra in the near-wall region. These results clearly show that the turbulence statistics scaled on inner variables are Reynolds-number dependent in the aforementioned range of Reynolds numbers. For example, the constants in the dimensionless logarithmic mean-velocity profile are shown to vary with Reynolds number. Our conclusion that turbulence statistics depend on the Reynolds number is consistent with results found in other flow configurations, e.g., a channel flow. Our results for the pipe flow, however, lead nevertheless to quite different tendencies.

Pitot probe corrections in fully developed turbulent pipe flow

“…Figure 11 shows the collapse of the four mean velocity profiles taken at Re D = 75 × 10 3 under each correction. The MacMillan and new corrections lead to excellent collapse with diameter and good agreement with the laser Doppler anemometry (LDA) measurements of pipe flow at Re D = 24 600 by den Toonder and Nieuwstadt (1997). Similar results are observed at Re D = 150 × 10 3 .…”

“…den Toonder and Nieuwstadt have shown previously that their LDA measurements in pipe flow (shown here at Re D = 24 600) agree well with y + = u + and the DNS of Eggels et al for pipe-flow at a lower Re D = 5300 for y + < 20. Therefore the LDA data of den Toonder and Nieuwstadt (1997) are assumed to be an accurate representation of the true nearwall velocity profile (note that in general, the LDA technique may suffer from its own resolution issues). However, we see that Spalding's relationship diverges from the LDA and DNS results for 20 < y + < 70 approximately.…”

Spectral element-Fourier methods applied to simulation of turbulent pipe flow

“…The velocity has been non-dimensionalised using the friction velocity, u τ . Experimental data [2] is provided for comparison. It can be seen that the Cartesian simulation provides good agreement with experimental data while the cylindrical simulation differs by approximately 3% for most of the profile.…”

“…Before proceeding to the more complicated jet simulations the accuracy of the cylindrical coordinate code must be verified. Turbulent pipe flow provides a means to check the accuracy of the code as both experimental [2] and computational [3] data is available against which to compare the results. The results will also provide a database of turbulent velocity data that can be used as inlet conditions in later simulation of jet-type flows.…”

“…The friction velocity Reynolds number used in previous experimental investigations are Re τ = u τ D/ν = 338 [2] and for the computations Re τ = u τ D/ν = 360 [3].…”