[teguhtf]

Dear all,

I want to simulate helical pipe by using a periodic boundary condition due to less computational efforts to get fully developed profile. I only simulate one turn. Flow is laminar, fluid is water, pipe diameter 26 mm and spiral diameter 139.8 mm. Mass flow rate is 0.034 kg/s. I am using Ansys FLUENT 17. But, I find distribution pressure is bad. (see Figure Periodic Trial).

I find a paper of "torisonal and curvature effect on fluid flow in a helical annulus". They use finite difference and based on projection algorithm (see figure 1 period and helix). They also use periodic boundary condition and succeed.

I see they use an orthogonal helical coordinate system. So the velocity vector could go easily.

in FLUENT Periodic option is only in Cartesian coordinate.

How I can put my mass flow rate in the helical system in FLUENT 17?

Do you have any suggestion?

Thank you for your help
Best regards
Teguh

[LuckyTran]

You can't use a helical coordinate system in Fluent. You are stuck with cartesian in 3D.

[teguhtf]

Dear Lucky Tran,

Thank you for answering the question. I have tried to make full scale but it always stuck in the computer power. I was thinking to use periodic boundary condition as the solution. I prefer to use full scale it makes me easier to do. But, my supervisor keeps on asking me to use periodic boundary condition in FLUENT. I need to obtain a fully developed flow

Can I use UDF on PBC or other boundary condition which like PBC?
Or you have any other suggestion?

I am sorry if my question is too silly.

Thank you
Best regards

Teguh