How to chose correct option when laminar and turbulent happens in the same device in
 

Dear all,

I would like to do simulation in spiral pipe but i make extension in inlet part and outlet part by straight pipe. The extension connected with spiral (i attach the file). Critical Reynolds number for coil is 5332. I do simulation in Re 3086. When i do simulation by using Laminar the result far below the theoretical result.

I think for straight pipe is turbulent regime and curved pipe is laminar regime. But hoe to solve this? Do I need to simulate with Turbulent regime?
Do you have any suggestion?

Thank you for your help
Teguh