Regensburg 2019 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 18: Fluid physics and turbulence

DY 18.6: Talk

Tuesday, April 2, 2019, 11:45–12:00, H20

Power-law scaling of friction in pipe flow — •Jose M. Lopez, Davide Scarselli, Balachandra Suri, and Bjoern Hof — Institute of Science and Technology (IST), Klosterneuburg, Austria

We present a study of the friction factor scaling for pipe flow at moderate Reynolds numbers (5000<Re<120 000) in experiments and highly resolved direct numerical simulations. The experimental and numerical data are in excellent agreement and we find that for Re<80 000 they do not follow the Karman-Prandtl friction relation. Instead the friction factor precisely follows the Blasius power law. This power law scaling can also be derived based on Kolmogorov's first hypothesis (assuming local isotropy) in line with an earlier study. Finally, we will show that the deviation of the friction factor from the power law scaling (Re>80 000) is related to the increasing dominance of the large scale motions in the logarithmic layer.