Fluent flow model
 

Dear Freinds,

I kindly ask you to help me in my design problem. I use tube in twist tape insert and the input Reynolds number varies between 200-1500. I confused which model shall i use the laminar depending on input reynolds number or turbulent due to to swirl folow induced in side tube becuse of twist tape.

Regards

There is no contradiction between laminar flow and swirling flow. I mean a swirling laminar flow is possible. Also input reynolds number is not a good criterion for turbulence in your case. Just try with laminar first. Supposing high quality mesh, if you couldnt converge your solution with laminar, it means that turbulence is being produced in your domain.
In many cases, with turbulence it is possible to simulate a laminar flow but not in opposite way.

Use k epsilon it's valid for laminar and turbulent flow

Fluent flow model
 

Dear Friends

Greeting, thanks for your reply

with regards

hi
 

for low Reynolds Number Flow that experience adverse pressure gradient use Spallart Allmaras model with Y+ less than 1 or
use KW Transition Model (4 Equation model that added in fluent Ansys15) with y+ less than 1.