Cyclic Orthotropic property in Fluent
 

Hi all,
I have modeled a conduction problem in Fluent of a Stator along with its conductors. I have split the conductor into 2, the active part along the stack length as well as the end winding. I have given cyclic orthotropic thermal conductivity property to it.
Unfortunately when I run the simulation, I'm getting erroneous results. There is a sudden jump in the steady state temperature result over iterations making it fluctuate from -ve to a high positive value with the following errors,
"temperature limited to 1 in fluent"
"temperature limited to 1.0000e+00001 in cells"
But when I model the end winding as constant thermal conductivity, others being orthotropic, the solution is converging and I'm getting a proper result.
The mesh is with the best quality: Min Orthogonality =0.11 & Max Skewness = 0.85


When I increase the value of thermal conductivity from 0.8 (like 5-10 W/mk), Iam able to get a solution without fluctuations. I'm not understanding why ?!


I notice that the energy residuals are also increasing and then becoming a constant in the later case.




Can you guys help in finding a solution?