Passive scalar structures in peripheral regions of random flows
A. Chernykh+*, V. Lebedev∇
+Institute of Automation and Electrometry SB RAS, 630090 Novosibirsk, Russia
*Novosibirsk State University, 630090 Novosibirsk, Russia
∇ Landau Institute for Theoretical Physics RAS, 117334 Moscow, Russia
PACS: 05.10.-a, 05.20.-y, 05.40.-a, 47.27.-i
Abstract
We investigate statistical properties of the passive scalar near
walls in random flows assuming weakness of its diffusion. Then at advanced
stages of the passive scalar mixing its unmixed residue is concentrated in a
narrow diffusive layer near the wall. We conducted numerical simulations and
revealed structures responsible for the passive scalar transport to bulk,
they are passive scalar tongues pulled from the diffusive boundary layer. The
passive scalar integrated along the wall possesses well pronounced scaling
behavior. We propose an analytical scheme giving exponents of the integral
passive scalar moments, the exponents agree reasonably with numerics in 3d.