[mithdradates]

Okay, got it. Thanks!

[mithdradates]

Thank you, I was able to implement a solid wall boundary via virtual densities method. But I’m still struggling with other boundary conditions. I have a question about envelope cells in SCMP Shan-Chen model – if e.g. I’m using SCMP for fluid only (material number 1) and fluid is constrained by boundaries on edges (material number 2), then “envelope” cells used in SCMP (newX0-1 etc.) are the boundary nodes or still the actual envelope nodes (outside of computational domain) ?

• This reply was modified 4 years, 10 months ago by mithdradates.
• This reply was modified 4 years, 10 months ago by mithdradates.

[mithdradates]

I’m unable to edit my post, I’d like to add that I tried your suggestion 1 and the results are still the same. I can’t even implement a solid wall boundary, because the code instantly fails when periodicity is turned off. Any help would be appreciated.

• This reply was modified 4 years, 10 months ago by mithdradates.
• This reply was modified 4 years, 10 months ago by mithdradates.

[mithdradates]

Hello, Max

Yes, I’m using the latest version of OpenLB.

1) Ok, I’ll try. Thanks for the suggestion!

2) Sorry, I don’t quite understand why I need gravitational force in the domain ? My initial idea was to use thermal SCMP SHan-Chen method as you suggested – to change density in every cell of the lattice according to their respective temperatures through EOS, but the simulation quickly destabilizies :\ Yes, I’ve tried with numbers from literature, the result is the same.

3) Okay, thanks!

[mithdradates]

Hello Max,

to 1 & 2: Okay, thank you!

to 3: As far as I understand, I can use SuperFiniteDifference3D to calculate derivatives. Correct?

to 4: I was looking for Neumann outflow condition (dP/dn = 0 – zero gradient) for pressure.

Thanks again!

[mithdradates]

Hello Max,

1: That sounds great, thank you for your work! Do you have any information on the date of the next release (somewhere in April or sooner \ later)?

2: So I don’t actually need coupling through boussinesq force term if I have a temperature already in my EOS, is that correct? I mean can I simply reimplement coupling by using PengRobinson pontetial’s overloaded () operator to include temperature from the ADLattice? Just want to make sure I understood you correctly.

I also have some additional questions (as you seem to be very knowledgeable on the subject), if you don’t mind.

3: Are there any in-built functions to calculate derivatives or divergence in OpenLB? I found AnalyticalDiffFD1D functor (from the description: “Derivative of a given 1D functor computed with a finite difference”), but as far as I understand it is suited to compute derivatives of functions (via (f(x + eps) – f(x)) / eps), not physical values like velocity or density.

4: Is there a zero-gradient (neumann) boundary for pressure in OpenLB?

Hope I didn’t take too much of your time. Thank you!

• This reply was modified 5 years, 1 month ago by mithdradates.

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