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Issues about tracking interface with level-set and phase field method

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Hi everyone, I am trying to make a level-set model for tracking water-air interface in a 2D micro-scale geometry. The geometry is built with one inlet channel, one square, and one outlet channel. The two physics, two-phase laminar flow and level-set method, are applied in component.

The objective is to track the interface of water-air. The water is injected from the left inlet and displaces the air throughtout the whole domains. All parameters in level-set are setted defaults except the fluid properties, general water and air at 20°C. The wetted-wall were added with a pi/4 contact angle. The mesh is mapped elements.

When the water entries into the square area, the interface should be considered as a growing droplet until it touches with the two walls of square domain. However, the result of volume fraction of fluid is not shown reasonablely as expected (as presented in the GIF). I tried to change the reinitialization parameter (maximm of velocity) and interface thickness (hc/2), even relative tolerance, the mesh type and using phase field method. Sometimes, it gives better shapes, but still not symmetric shapes of interface in the square domain.

I am confued with the settings, because I have tried almost everything. Does anyone know why it happens and how to solve it? Thank you so much in advance.



2 Replies Last Post Jun 17, 2020, 9:39 p.m. EDT

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Posted: 4 years ago May 25, 2020, 4:55 a.m. EDT

Hello, does anyone know these issues? Thanks.

Hello, does anyone know these issues? Thanks.

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Posted: 4 years ago Jun 17, 2020, 9:39 p.m. EDT

I think that the capillary force is so large that a perturbation can lead to unstable. this problem may be solved by reduce the capillary force through contact angle. Or, Add rounded corner to decrease the perturbation.

I think that the capillary force is so large that a perturbation can lead to unstable. this problem may be solved by reduce the capillary force through contact angle. Or, Add rounded corner to decrease the perturbation.

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