Large-eddy simulations of convective boundary layers using nonoscillatory differencing

We explore the ability of nonoscillatory advection schemes to represent the effects of the unresolved scales of motion in numerical simulation of turb ulent flows. We demonstrate that a nonoscillatory fluid solver can accurate ly reproduce the dynamics of an atmospheric convective boundary layer When an explicit turbulence model is implemented, the solver does not add any si gnificant numerical diffusion. Of greater interest, when no explicit turbul ence is employed the solver itself appears to include an effective subgrid scale model. Other researchers have reported similar success, simulating tu rbulent flows in a variety of regimes while using only nonoscillatory advec tion schemes to model subgrid effects. At this point there is no theory jus tifying this success, but we offer some speculations. (C)1999 Elsevier Scie nce B.V. All rights reserved.