A question on fluid motion...

Palabos General
#1

Greetings to all!

I want to know which is the best method to model a fluid pouring or spilling on the floor. I hope to be able to see the liquid adding up (volume) and spreading, just like when one drops a glass of water, something like that.

Thanks

#2

From the information you have given a Shan-Chen multicomponent LB model would be a good place to start

#3

Any free-surface model will be a good match. You can check videos of Niels Thuerey - http://graphics.ethz.ch/~thuereyn/ntoken3/pubs.html

Cheers,
Alex

#4

Thank Bruce and Alex. I am reading about free-surface models so i can make my fluid spill program. I also found some literature on how to fill a cavity: Cavity fill. I have not been able to figure out is how i can make the water start spreading… maybe if I add a force, say wind force? Or should I try something different

#5

Hi Alex,

Actually i am reading these paper on the web page you recommended Free Surfaces. I should try to implement these with the Sha/Chen model that bruce pointed me out, right?

#Edit 1
Hello again,

From what I have read the free surface models consist of a lattice with 3 types of cells. One is a cell completely filled with fluid, another is the opposite (a cell without fluid) and the third one is a cell which is partially filled. I know Palabos handles fluid and non-fluid cells, but i don’t know if it is capable of handling the partially filled one… Do i need to include these cell type into Palabos for it to work correctly (it seems so). Plus, the method of colliding and streaming pointed here is different as one has to treat the partial fluid cells first, then stream the cells with partial and completely filled with fluid and later reconstruct the cells which have no fluid and the collide. So I have no idea on how I will be able to stream only those kind of cells.

#6

Hello,

Basically free-surface models are not based on the Shan-Chen method. Unfortunately I can’t comment on the Palabos implementation - Jonas and Orestis can comment more on it.

For the free-surface method probably it’s easier to write your own code. I’ve never dealt with 3D but small 2D free-surface model based on the shallow water equation can be sent to you if you need it.

Sorry can’t provide a lot of details, as I didn’t work with it,
Alex

#7

Hi Alex!

I appreciate any code you can give me, thank you. Right now I am focusing my efforts on following the papers and trying to code them into palabos. The issue here is that I have to use LBM to achieve this fluid motion because is the focus of my project, or else I would have implemented another type of solver.

Related, I have also checked a fluid solver for shallow water equations on a personal web page of Jos Stam (One of the authors of the papers I am reading). If Jonas can give me some guidance on how I can distinguish the cell type described above, would be great.

Thank you again Alex for the info and the will to help.

#8

Hello,

What is your email? Is it the same as in the profile?

Cheers,
Alex

#9

Alex Wrote:

Hello,

What is your email? Is it the same as in the
profile?

Cheers,
Alex

Yes! you can send it to the one listed on the profile.

Thanks Alex !