[D. Fai]

Dear Sir/ Madam,


I hope my message finds you well.
I am trying to model the flow in a capillary using FLUENT.
Dimensions (L = 1000 mm, D= 1.5 mm).
Problem: I have got numerical errors related to the large ratio (L/D).
Is there any way to overcome this problem?
I have found in the literature that applying dimensionless length and radius might help, but I couldn't figure out how to do so.
If you have any suggestions/course/book, on how to model the flow inside such a capillary, I would really appreciate your time and experience.
I wish you a good day

[AlexanderZ]

dimensionless length sounds interesting to me

may I ask you what exactly are you trying to model and which results do you expect to get?
depends on your goals, mesh structure may be different


the structure of your domain is also playing role here from my point of view: i mean location of your boundary conditions.

[D. Fai]

Originally Posted by AlexanderZ

dimensionless length sounds interesting to me

may I ask you what exactly are you trying to model and which results do you expect to get?
depends on your goals, mesh structure may be different


the structure of your domain is also playing role here from my point of view: i mean location of your boundary conditions.

Dear Alexander Z,


I am trying to model Capillary membrane - horizontal position(dimension Length=1000mm, Diameter= 1.5 mm).
I would like to see the velocity profile of water enters from the right side, and flow out from the wall. But as I said before, I am facing numerical errors due to the large ratio L/D.
I wish you could help me, or suggest a course/ method, how to overcome this problem.
I wish you a good day sir