Negative streamwise velocities and other rare events near the wall in turbulent flows

Lenaers P, Li Q, Brethouwer G, Schlatter P, Orlu R (2011)

Publication Type: Conference contribution

Publication year: 2011

Publisher: Institute of Physics Publishing

Book Volume: 318

Conference Proceedings Title: Journal of Physics: Conference Series

Event location: POL

DOI: 10.1088/1742-6596/318/2/022013

Abstract

Negative streamwise velocities, extreme wall-normal velocites and high flatness values for the wall-normal fluctuations near the wall are investigated for turbulent channel flow simulations at a series of Reynolds numbers up to Reτ = 1000 in this paper. Probability density functions of the wall-shear stress and velocity components are presented, as well as joint probability density functions of the velocity components and the pressure. Backflow occurs more often (0.06% at Reτ = 1000) and further away from the wall into the buffer layer for rising Reynolds number. An oblique vortex outside the viscous sublayer is found to cause this backflow. Extreme v events occur also more often for rising Reynolds number. Positive and negative velocity spikes appear in pairs, located on the two edges of a strong streamwise vortex: the negative spike occurring in a high speed streak indicating a sweeping motion, while the positive spike is located between a high and low speed streak. These extreme v events cause high flatness values near the wall (F(v) = 43 at Reτ = 1000).

Authors with CRIS profile

Philipp Schlatter

Involved external institutions

Royal Institute of Technology / Kungliga Tekniska Högskolan (KTH) SE Sweden (SE)

How to cite

APA:

Lenaers, P., Li, Q., Brethouwer, G., Schlatter, P., & Orlu, R. (2011). Negative streamwise velocities and other rare events near the wall in turbulent flows. In Journal of Physics: Conference Series. POL: Institute of Physics Publishing.

MLA:

Lenaers, Peter, et al. "Negative streamwise velocities and other rare events near the wall in turbulent flows." Proceedings of the 13th European Turbulence Conference, ETC13, POL Institute of Physics Publishing, 2011.

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