lionel agostini Leschziner, Michael
Published in
Physical Review Fluids
Direct numerical simulation data for channel flow at a friction Reynolds number of 4200, generated by Lozano-Durán and Jiménez [J. Fluid Mech. 759, 432 (2014)], are used to examine the properties of near-wall turbulence within subranges of eddy-length scale. Attention is primarily focused on the intermediate layer (mesolayer) covering the logarithm...
lionel agostini Leschziner, Michael
Published in
Physics of Fluids
The “quasi-steady hypothesis,” as understood in the context of large-scale/small-scale interactions in near-wall turbulence, rests on the assumption that the small scales near the wall react within very short time scales to changes imposed on them by energetic large scales whose length scales differ by at least one order of magnitude and whose ener...
lionel agostini Leschziner, Michael
Published in
Physics of Fluids
A phenomenological model is provided, based on post-processing Direct Numerical Simulation (DNS) data at Reτ = 1020, which permits the near-wall-turbulence statistics to be predicted from a “universal signal,” free from the effects of large-scale motions, in combination with information on the large-scale motions in the outer log-law region. The se...
lionel agostini Leschziner, Michael Gaitonde, Datta
Published in
Physics of Fluids
Several recent studies discuss of role of skewness of the turbulent velocity fluctuations in near-wall shear layers, in the context of quantifying the correlation between large-scale motions and amplitude variations of small-scale fluctuations—referred to as “modulation.” The present study is based on the premise that the skewness of the small-scal...
lionel agostini Leschziner, M. A.
Published in
Physics of Fluids
Direct Numerical Simulation (DNS) data for channel flow at 1025 are used to analyse the interaction between large outer scales in the log-law region – referred to as super-streaks – and the small-scale, streaky, streamwise-velocity fluctuations in the viscosity-affected near-wall layer. The study is inspired by extensive experimental investigations...
