New-wall modeling for complex flows using the large eddy simulation technique in curvilinear coordinates

This investigation presents modifications and improvements to the dynamic s ubgrid scale model and introduces a new-wall model. These modifications are implemented in the large eddy simulation technique in curvilinear coordina tes. They are then validated and tested in three-dimensional complex geomet ries. The large eddy simulation method captures many scales of turbulence u p to the grid size. A closure model is used to simulate subgrid turbulence. The Smagorinsky and dynamic subgrid models are presented and tested. The d ynamic model overcomes many of the deficiencies of the Smagorinsky subgrid scale model. Spatial and temporal low-pass filters have been introduced in the dynamic subgrid scale model for numerical stability. Several near-wall models are considered for the large eddy simulation technique, A local aver aging technique lends these models to be applicable in complex geometry sit uations. A new model is introduced which overcomes planar averaging near th e wall and captures ejection and sweep effects. These models have been impl emented in a large eddy simulation computer program. Results are validated and tested in a lid driven cavity flow at Reynolds number of 10 000. A sing le tube in a channel is simulated to show the applicability of the models t o complex geometries with attachment and separation as well as end-wall eff ects. The shedding effect was captured and turbulence statistical character istics were acceptable. (C) 2001 Elsevier Science Ltd. All rights reserved.