Transition Reynolds Number for flux inside a heat pipe
 

Hi everybody,
I am simulating (using Fluent 12.1) a flux of oil in a heat pipe. Obviously the turbulence of the fluid influences the heat flux generated. I have Reynolds = 1911, which turbulence model is the best to use in this case? Should I use the laminar model? If no, which transition model is the best for my application? I hope I've been clear.
Thank you all!