Grid-Independent Large-Eddy Simulation in Turbulent Channel Flow Using Three-Dimensional Explicit Filtering
Abstract
The most commonly used Large Eddy Simulation (LES) approach is the implicitly filtered approach. In implicitly filtered LES, the computational grid and the discretization operators are considered as the filtering of the governing equations. Thereby the turbulent flow field is divided into grid resolved and unresolved scales, where the unresolved scales must be modeled. When explicit filtering is used in LES, the filtering procedure of the governing equations is separated from the grid and discretization operations. The flow field is divided into resolved filtered scale (RFS) motions, and subfilter-scale (SFS) motions. The SFS is itself divided into a resolved part (RSFS) and an unresolved part (USFS) (Zhou et at. 2001); see figure 1. The RFS motion is obtained by solving the filtered Navier-Stokes equations. The RSFS motions can be reconstructed from the resolved field and occur due to the use of a smooth (in spectral space) filter function. The USFS motions consist of scales that are not resolved in the simulation and need to be modeled. The explicitly filtered governing equations were recently studied by Carati et al. (2001) in forced isotropic turbulence.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2003
- Accession Number
- ADP014815
Entities
People
- Jessica Gullbrand
Organizations
- Lund University