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Reply To: wetting with free surface or large density ratio

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Hello Matt,

Unfortunately, the current implementation of the free energy model only considers equal densities. A non-equal model is something that we are interested in implementing in the future, but is not currently included.

It is worth considering if the problem actually requires a high density ratio. If the Reynolds number of the system is small (Re<<1) then an equal density model may be able to accurately simulate the system so long as the correct viscosities are assigned. Although, if inertia is important (Re>=1) then the density ratio must be accurate.

Regarding the setFreeEnergyWallBoundary function, it can only be used in conjunction with the free energy model. I don’t believe there are any similar wetting conditions implemented yet for the free surface or Shan-Chen model.

For Shan-Chen, a wetting condition could be implemented using an additional solid-liquid interaction (for example, see this paper: As for the density ratio, I believe there is a working prototype with density ratios of up to 1000, but this is not fully implemented yet.

And of course, all OpenLB models can be adapted and extended. In the framework of a common project we are happy to help with this!

Best wishes,