[johanna]

Hello,

the implemented advection diffusion temperature boundaries are based on the scheme given in the book “The lattice boltzmann method” (Chapter 8.5) by Krüger et al. There are also further references to papers given.

Best,
Johanna

[johanna]

Hello steed188,

can you please send me more informations about the project and the points were you need some support at my mail adresse johanna.moedl@kit.edu. Then I can also give you some further informations.

I am looking forward to your hear from you.
Best wishes,
Johanna

[johanna]

Hello steed188,

please try first to use AdvectionDiffusionTemperatureBoundaries to check if it does really depend on the boundary condition.

Here we can not give such detailed support but as a cooperation project this would be possible. If this works for you just contact us.

Best wishes,
Johanna

[johanna]

Hello steed188,

sorry for the late response.
Can you describe why you think that it does not seem to work? Do you get a compilation error or does the result look not the way you expected it?

Best,
Johanna

[johanna]

Hello Antonio,

you can access the temperature data via SuperLatticeDensity and then you could also convert it into an analytical functor with AnalyticalFfromSuperF…D if you have the physical coordinates for nx-1.
Alternatively you could use a PostProcessor. There you could use for example blockLattice.get(iX-1,iY).computeRho().
To set the boundary condition use in your App a setBoundaryValues method and the advectionDiffusionTemperatureBoundaries and set your value in every time step with LatticeName.defineRho(…)

Best,
Johanna

[johanna]

Hello Sahil,

unfortunately there is no example with Neumann boundary conditions for Advection-Diffusion equations.
But you can simply use a difference quotient to transform your Neumann boundary into a Dirichlet boundary (fixed temperature boundary) and update it every timestep with a setBoundaryValues method.

Best
Johanna

[johanna]

Dear Antonio,

I recently had the same problem in my application and we are working on an appropriate implementation of Neumann boundaries for ADlattices. So far I would suggest to transform your flux boundary condition into a dirichlet boundary condition via finite differences. This is for example explained in https://link.springer.com/book/10.1007/978-3-319-44649-3.

Best regards,
Johanna

[johanna]

Dear Xu Yang,

i would suggest to try the setZeroDistributionBoundary which sets every population with direction into the bulk to zero.
I hope this fits to your application case.

Yours sincerely,
Johanna

[johanna]

Hello John,

we are currently working on some Neumann boundary conditions. I can not promise that it will help you for your SC mulit-component model but in general I can recommend the paper about non-eq. extrapolation boundaries (https://iopscience.iop.org/article/10.1088/1009-1963/11/4/310/pdf ).

Best regards,
Johanna

[johanna]

Dear Antonio,

for Neumann boundary conditions that are not zero you could use the setInterpolatedConvectionBoundary or the local version setLocalInterpolatedConvectionBoundary that are made for Navier Stokes equations. You have to check if this also fits for your ADE application.

If you want to use a source-termed ADE use a field SOURCE and then calculate in a Post Processor (you can also include it in your coupling Post Processor) the source term with the computeRho method and set for each voxel your source term. The SOURCE field is then used by the SourcedAdvectionDiffusionBGKdynamics.

Best regards
Johanna

[Author]

Posts