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Fluid dynamics simulation of capillary tube
Posted Sep 19, 2014, 3:36 a.m. EDT Computational Fluid Dynamics (CFD) 1 Reply
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Hi, I am working on a project to simulate fluid speed field in capillary tube. The model could be described as follows:
A capillary tube is insert between two gas chamber, one is at atmosphere pressure, and the other is under roughly 3kPa vaccum. The inner diameter of the tube is 0.6mm, and length is roughly 180mm. I build a geometry model as attached. I used k-epsillon turbulent model to solve my problem. The mesh I choosed is standard.
At first glance the problem is not difficult. But after try different conditions several times, the program still end with error.
Would anyone give me some suggestions on the correct modeling of this problem? Thank you very much.
Best
--Toyonline
A capillary tube is insert between two gas chamber, one is at atmosphere pressure, and the other is under roughly 3kPa vaccum. The inner diameter of the tube is 0.6mm, and length is roughly 180mm. I build a geometry model as attached. I used k-epsillon turbulent model to solve my problem. The mesh I choosed is standard.
At first glance the problem is not difficult. But after try different conditions several times, the program still end with error.
Would anyone give me some suggestions on the correct modeling of this problem? Thank you very much.
Best
--Toyonline
Attachments:
1 Reply Last Post Sep 23, 2014, 8:13 a.m. EDT
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Posted:
10 years ago
Hi Felix
It is a bit difficult to pin point exactly but it could be one of the following:
1) Too coarse of a mesh - your tube is very small and high gradients are present near the wall which I assume are no slip conditions.
2) Turbulence model - The k-epsilon model is very robust and reliable however, for steep gradients the k-omega can be better.
What is the error message? Your error could also be related to lack of boundary conditions, poor initial conditions etc.
Best Regards
Mikael
It is a bit difficult to pin point exactly but it could be one of the following:
1) Too coarse of a mesh - your tube is very small and high gradients are present near the wall which I assume are no slip conditions.
2) Turbulence model - The k-epsilon model is very robust and reliable however, for steep gradients the k-omega can be better.
What is the error message? Your error could also be related to lack of boundary conditions, poor initial conditions etc.
Best Regards
Mikael