Direction of scalar transport in turbulent channel flow

摘要: The concept of reverse diffusion, introduced by Corrsin to describe the motion particles as they move towards a location in flow field, is fundamental understanding mixing. In this work, direct numerical simulations conjunction with tracking scalar markers are utilized infinitely long channels study principal direction transport heat (or mass) for both forwards and backwards single particle dispersion. viscous sub-layer, transition region (between sub-layer logarithmic region), Poiseuille plane Couette channel studied. Fluctuating velocities captured these regions used obtain full autocorrelation coefficient tensor time. highest eigenvalue velocity correlation quantifies amount turbulent transport, while corresponding eigenvector points main transport. ...