Gamma ReTheta Transition Model
 

hi..i am fresher for CFD..what is the solution for error..Gamma ReTheta Transition Model must have valid field function set for free stream edge definition..

You must define the freestream edge so that the freestream momentum thickness Reynolds number can be transported into the boundary layer.

Create a field function (Tools > Field Function).

Define the field function. The Help file of CCM+ uses this as an example:$WallDistance > 0.005?1:0
(if the wall distance is larger than 5 mm, then that is the freestream; otherwise, it's the boundary layer).

In Continua > Physics > Models > Gamma ReTheta, set the Free Stream Edge to your user-defined field function.

I am using StarCCM+ to model open water performance of the propeller. I know how to set the field function for freestream edge. But, I do not know how can we calculate the wall distance correctly for freestream edge definition. Also, what is the significance of this freestrream edge? Does StarCCM+ uses different turbulent model equations within the boundary layer and in free stream?
Thank You.