turbulence intensity values displayed by Fluent are different from what they should be
Users somtimes notice that in the FLUENT post-processing, the turbulence intensity gives bogus values (very large or very small) and associates that to a display problem.
When they compute sqrt(ke)/|V| the values are near what they would expect.
The values reported for Turbulence Intensity (TI) are based on the reference velocity, which is defined in the reference values panel (Report -> Reference Values).
The turbulence intensity being defined by FLUENTas :
TI = sqrt( (2/3)*k )/Vref
However, some users prefer to use the local velocity magnitude:
TI = sqrt( (2/3)*K )/Vmag-local
To do this, one has two alternatives :
1) Define a Custom Field Function using the above expression that involves Vmag-local
2) Change Vref in the reference panel from the 1.0 m/s default value.
In FLUENT 6, the Turbulence intensity is given as percentage as opposed to fraction in Fluent 5.6 and below.