[Agad15]

I am simulating 2D (also 3D) pipe flow using VOF. Results are good if I don't activate surface tension and wall adhesion. But in order to know the surface tension and wall adhesion (contact angle given) effects I activated those, but the results what I am getting are very un-physical. What could be the reason?

PS: Experimental results are in good agreement with what we expected with the contact angle and surface tension.

[Cucko]

Originally Posted by Agad15

I am simulating 2D (also 3D) pipe flow using VOF. Results are good if I don't activate surface tension and wall adhesion. But in order to know the surface tension and wall adhesion (contact angle given) effects I activated those, but the results what I am getting are very un-physical. What could be the reason?

PS: Experimental results are in good agreement with what we expected with the contact angle and surface tension.

Hi Agad,

do u simulate steady state or transient? It is important to set the Volume Fraction Parameters correct. I think for transient simulations u have to set the explicit sheme. The implicit sheme is not recommended for transient simulations. Maybe this can help u.
The Explicit sheme should be used in simulation of flows where surface tension isimportant because of highly accurate curvature calculation.

Greetings Cucko

[bansa9643]

Hello!

You could have already done it.. but an estimate of importance of surface tension forces by using the Bond/Eotvos number should be carried out..

Also, Cucko correctly indicated, VOF model parameters should be wisely selected to have coherent results.. the combination of Transient + Explicit + GeoReconstruct scheme should be quite stable! Try that out!

Best,
A.B.

[Meshermet]

Hi I also trying to use the surface tension and wall adhesion, for a 2 phases analysis between 2 fluid and a specimen, for simulating the process of dip coating, whit out those options I get the simulation done and I can se the layer of the the first phase around the specimen, but if I try to use the surface tension and wall adhesion, the solution diverge and fluent close.

Do you know what is making to diverge?

[Aaronaiy]

Originally Posted by bansa9643

Hello!

You could have already done it.. but an estimate of importance of surface tension forces by using the Bond/Eotvos number should be carried out..

Also, Cucko correctly indicated, VOF model parameters should be wisely selected to have coherent results.. the combination of Transient + Explicit + GeoReconstruct scheme should be quite stable! Try that out!

Best,
A.B.

Hello,
Do you know how to add the varible surface tension by UDF. I have tried many times, but I didn't obtain the desired results