# Contents

## Idea

As defined by Wikipedia:

Turbulence modeling is the construction and use of a model to predict the effects of turbulence. Averaging is often used to simplify the solution of the governing equations of turbulence, but models are needed to represent scales of the flow that are not resolved.

J. Blazek has described how common models relate to each other:

LevelModel name
Level 0Direct Numerical simulation (DNS)
Level 1Large-Eddy Simulation (LES)
Level 2Reynolds-Averaged Navier-Stokes equations
Level 22nd order (closures). Reynolds-Stress Transport models (RST)
Level 22nd order. Algebraic Reynolds Stress models (ARS)
Level 31st order (closures)

See also the numerical simulation part of the turbulence page, Large eddy simulation for more details.