7 papers · 1 filter
Investigating nonlinearity in wall turbulence: regenerative versus parametric mechanisms
B. F. Farrell, E. Kim, H. J. Bae +2
Both linear growth processes associated with non-normality of the mean flow and nonlinear interaction transferring energy among fluctuations contribute to maintaining turbulence. H…
Mechanism of Roll-Streak Structure Formation and Maintenance in Turbulent Shear Flow
B. F. Farrell, P. J. Ioannou, M. -A. Nikolaidis
In wall-bounded shear flow the primary coherent structure is the streamwise roll and streak (R-S). Absent of an associated instability the R-S has been ascribed to non-normality me…
Cause-and-effect of linear mechanisms sustaining wall turbulence
Adrián Lozano-Durán, Navid C. Constantinou, Marios-Andreas Nikolaidis +1
Despite the nonlinear nature of turbulence, there is evidence that part of the energy-transfer mechanisms sustaining wall turbulence can be ascribed to linear processes. The differ…
Alternative physics to understand wall turbulence: Navier-Stokes equations with modified linear dynamics
Adrán Lozano-Durán, Marios-Andreas Nikolaidis, Navid C. Constantinou +1
Despite the nonlinear nature of wall turbulence, there is evidence that the energy-injection mechanisms sustaining wall turbulence can be ascribed to linear processes. The differen…
Wall turbulence without modal instability of the streaks
Adrián Lozano-Durán, Marios-Andreas Nikolaidis, Navid C. Constantinou +1
Despite the nonlinear nature of wall turbulence, there is evidence that the mechanism underlying the energy transfer from the mean flow to the turbulent fluctuations can be ascribe…
Parametric mechanism maintaining Couette flow turbulence verified in DNS implies novel control strategies
Brian F. Farrell, Petros J. Ioannou, Marios-Andreas Nikolaidis
The no-slip boundary condition results in a velocity shear forming in fluid flow near a solid surface. This shear flow supports the turbulence characteristic of fluid flow near bou…