Analysis of a scale-similarity model of the motion of large eddies in turbulent flows

[摘要] In turbulent flow, the normal procedure has been to seek means (u) over bar of the fluid velocity u rather than the velocity itself. If these means are defined by local spacial averaging with an averaging radius of delta the approach is known as large eddy simulation, and (u) over bar denotes the eddies of size 0(delta) and larger. One approach to the closure problem which arises from averaging the nonlinear term is use of a scale-similarity hypothesis. We consider one such scale-similarity model. For this model we show the solution it, to the model for (u) over bar converging to u as the averaging radius delta --> 0. We also show that the error parallel to(u) over bar - wparallel to is bounded by the modeling error (perhaps better termed modeling residual), evaluated on the true solution it. This last bound suggests one path to validating the model in either computational or physical experiments. (C) 2001 Elsevier Science.

[发布日期] 2001-12-15

[关键词] Navier-Stokes equations;large eddy simulation;scale similarity;turbulence