Direct numerical simulation of unsheared turbulence diffusing towards a free-slip or no-slip surface

Experimental study of oscillating-grid turbulence interacting with a solid boundary

“…Similar results were also reported in the experimental study of Aronson et al (1997) using a 'moving belt' configuration for Re T between 325 and 425 (Aronson et al 1997). Most recently Bodart et al (2010) reported a DNS study of zero-mean-shear turbulence produced in a cubic domain by a random forcing field within a thin horizontal layer equidistant from two opposite, horizontal, boundaries of the cube. The turbulence decayed vertically across the region between the source layer and the boundary, in a manner comparable to OGT.…”

“…The turbulence decayed vertically across the region between the source layer and the boundary, in a manner comparable to OGT. Bodart et al (2010) reported that u was monotonically reduced by the presence of the boundary, but that it attains an approximately constant value across a proportion of the boundary-affected region. (In this study, Re T = 100 at the edge of the source layer.…”

“…The problem has also been studied using numerical simulation (Biringen & Reynolds 1981;Perot & Moin 1995;Bodart et al 2010). Perot & Moin (1995) used direct numerical simulation (DNS) to study the instantaneous insertion of a boundary into a field of zeromean, homogeneous, isotropic turbulence.…”

Threshold Criteria for Incipient Grain Motion with Turbulent Fluctuations on a Horizontal Bed

“…From there, u decreases to zero at the sediment bed to satisfy the no slip condition. The turbulent profile obtained is similar to that obtained in previous studies of zero mean turbulence at near solid boundary (Aronson et al 1997;Bodart et al 2010;Perot & Moin 1995).…”

“…The r.m.s vertical velocity w component monotonically decreases as ξ → 0, due to the kinematic boundary condition induced by the presence of the sediment bed. In contrast, the r.m.s horizontal velocity u component experiences amplification between 0.2 ≤ ξ/l 0 ≤ 1, attaining a peak value at ξ/l 0 ≈ 0.3 due to the inter-component energy transfer (Bodart et al 2010). From there, u decreases to zero at the sediment bed to satisfy the no slip condition.…”