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Convergence problem near boundary, two phase flow, level-set method

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Hi everyone. I'm working with droplet ejection. The droplet have the density and viscosity of water and the sorrounding fluid, density and viscosity of air. To solve it i'm using the level-set method.

There is no problem with the ejection, but when the drop reaches the boundary that it has to cross, the time step start going down and finally the solver stops.

I've changed that boundary conditions several times, i tried:

Outlet: Normal stress (f=0)

Open boundary: No viscous stress

Open Boundary: Normal stress (f=0)

But in every case the solution reaches the same problem when the droplet tries to pass trough that boundary.

What can i do to avoid this convergence in the boundary? what boundary condition should i use to avoid this problem?

I'm attaching an image of what i'm saying,


Thanks for the help!


0 Replies Last Post 15 apr 2013, 11:17 GMT-4
COMSOL Moderator

Hello Alfonso Santiago

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