It is an unfortunate fact that no single turbulence model is universally
accepted as being superior for all classes of problems. The choice of turbulence
model will depend on considerations such as the physics encompassed in the flow,
the established practice for a specific class of problem, the level of accuracy
required, the available computational resources, and the amount of time
available for the simulation. To make the most appropriate choice of model for
your application, you need to understand the capabilities and limitations of the
The purpose of this section is to give an overview of issues related to the turbulence models provided in FLUENT. The computational effort and cost in terms of CPU time and memory of the individual models is discussed. While it is impossible to state categorically which model is best for a specific application, general guidelines are presented to help you choose the appropriate turbulence model for the flow you want to model.