FVLBM (Did anyone make it work?)

Lattice Boltzmann Method LBM: Theory
#1

I have many papers about this method but i couldnot make it work. this is one of the papers

(Finite volume scheme for the lattice Boltzmann method on unstructured meshes)

this is my algorithm

initail condition (u,rho)
Convert_macro2micro(); // u, rho to dstribution function

time loop
{
FV_coll_AND_str();
Boundary();
Convert_micro2macro(); // dstribution function to u, rho
}

where FV_coll_AND_str(); contain the steps in the paper.

if anyone intresting i can post my code and we can talk about it

sorry for my english

best regard

#2

Hi SaS,
Sure you can post your code i am interesting to look at such code and we will disscus it no problem.
Good luck and bye

#3

Note that, depending on the size of your code, it may be more useful to create a new section on the Wiki[/url], upload it there, and link your Wiki page from the forum (see [url=http://www.lbmethod.org/community_wiki_intro]Wiki tutorial for help).

#4

thanks every body

this is the code

http://www.lbmethod.org/community:finite_volume_lbm_cell_vertex_scheme

if there is any thing not clear in the code we can discuss here

Note my code work on FDLBM only by changing three lines in the main function

double omega2=1./(visc/csq2+0.5); // for FDLBM
//double omega2=1/tau_lu; // for FVLBM

f2.collosion(omega2); // for FDLBM
f2.streaming(); // for FDLBM

// f2.FVon(Pnt(1,nX-2), Pnt(1,nY-2), dx_lu, dt_lu, tau_lu); // for FVLBM

sorry for my english

best regards

#5

Hi SaS,
I try to open your code the link you mention it (www.lbmethod.org) but i not find any code there. I would like to study such a code and to disscus with you.
Good luck and bye for now.
Khan

#6

sorry

this is the code

http://www.lbmethod.org/community:main

#7

Hi SaS
I tried to run your code by turbo c++ v.4.5 ,borland v.5 & visual c++, but I cann’t .please guide me.That’s very important for me to run it soon.
Thank you

#8

Hi SaS,

Are you using simple bounce back in your code for the boundary condition? I think that doesn’t work…
There is a paper by F.Dubois and P. Lallemand “On Lattice Boltzmann scheme, finite volumes and boundary conditions” in which it is described how to implement boundary condition. Actually it is a bit odd to me that simple bounce back doesn’t give the right results(indeed it doesn’t converge in my code).

Bests,

Nima.

#9

hi sas
in FDLBM, what are u doing in streaming? i have problem in streaming! in curvilinear grid, how can the particle stream?in what direction?
thank you!

yours
Ehsan

#10

hi every body

Note:
the FDLBM part of my code is woking very well and giving good results.
but FVLBM part of my code is not giving a good result.
also FVLBM part of my code is only working with uniform squar grid( simplist grid)

nastaran.mehboudi

you can compile my code using gcc compiler
actually I’m using Mingw under windows.

siboni

“Finite volume scheme for the lattice Boltzmann method on unstructured meshes”
“Finite-volume lattice Boltzmann schemes in two and three dimensions”
in the up mentioned papers it written


"In all the computations we present in this paper, the update
of the (fi) at boundary nodes is similar to that for interior
nodes except at the boundary the corresponding covolumes
are half-covolumes."

I think it means you can treat eatch (fi) normally (as FDLBM). after that in the boundary the change in volume contribution
and the source term witch should appear because the covolumes are not complete(see the figures in the papers)
should give us the correct boundary.

better read the papers up mentioned.
also I will read your paper then we can discuss.

ehsanf

in FVLBM the stream (“flux” as it is known in finite volume method) can be calculated using contribution of the neighbor cells. No need for directions.
For more information Read the two papers up mentioned.

But in curvilinear grid I don’t know how to do streaming.
You can read this paper for curvilinear grid.
“Explicit finite-difference lattice Boltzmann method for curvilinear coordinates”

best regards

SaS

#11

Hi
I think i read a paper that said Succi et.al work on FVLBM and they cant develop it and cant get a good result, after that, He et.al and Doolen, Mei, Shu, and le shi lu work on FDLBM, they said FDLBM could get better result, in meshless approaches and complex geometry.
I’ll try to find that paper and say you better.

Best
Ehsan

#12

i am working on a project fdlbm(finite difference latiice boltezmam )
and i need a code for lid cavity
and i need it very much
best regards
mahmoud