# General CFD FAQ

(Difference between revisions)
 Revision as of 11:52, 30 November 2005 (view source)Jola (Talk | contribs)← Older edit Revision as of 08:10, 5 December 2005 (view source)Tsaad (Talk | contribs) Newer edit → Line 1: Line 1: This FAQ is empty. This is just a suggestion on how to structure it. Please feel free to add questions and answers here! This FAQ is empty. This is just a suggestion on how to structure it. Please feel free to add questions and answers here! - + == Physics == + === What is the difference between the Reynolds decomposition and LES filtering? === + The Reynolds decomposition separates the velocity field into an average component and a fluctuating component. '''The time average of the fluctuating component is identically zero'''. In LES, a filtering operation is performed to decompose the velocity field into a ''filtered'' velocity field and a ''filtered residual'' field. The fundamental difference is that the filtered velocity field is a '''random variable''' and the time average of the residual field is generally '''nonzero''' == Numerics == == Numerics == === What is the difference between FEM, FVM and FDM? === === What is the difference between FEM, FVM and FDM? ===

## Revision as of 08:10, 5 December 2005

This FAQ is empty. This is just a suggestion on how to structure it. Please feel free to add questions and answers here!

## Physics

### What is the difference between the Reynolds decomposition and LES filtering?

The Reynolds decomposition separates the velocity field into an average component and a fluctuating component. The time average of the fluctuating component is identically zero. In LES, a filtering operation is performed to decompose the velocity field into a filtered velocity field and a filtered residual field. The fundamental difference is that the filtered velocity field is a random variable and the time average of the residual field is generally nonzero

## Numerics

### What is the difference between FEM, FVM and FDM?

Describe differences between the finite volume method, the finite element method and the finite difference method...