# How to use LBM to simulate phase change?

This could be thought as a moving boundary condition,but how to deal with?
Waiting for everyone’s help,thanks!

What kind of phase change do you want to simulate?
In principle, you have two different possibilities:

1. moving boundaries in a Lagrangian coordinate system, front-tracking
2. phase field on the lattice

Timm

In porous medium,the liquid changed into a gas.How to choose the model and boundary condition?
Thanks for your reply!

I havent done this personally, but I guess you’d need an equation of state and a coupled fluid/thermal LB model.

Not necessarily a thermal model, but a multiphase model with equation of state. For example, you could have a look at the Shan-Chen model.

Thank you,brucedjones and Timm!
I know little about Shan-Chen model,so I do not know how to separate the fluid and gas region.And the boundary is moving.
Can you describe that in detail?
Thanks a lot!

You mean the boundary between liquid and gas is moving? Or the solid-fluid boundary is moving?
It would be best if you could first explain in detail what the situation is. Which physical system do you want to simulate and what is the goal?

Timm

I mean that the boundary between liquid and gas is moving.
I want to simulate the startup and the course achieving to the balance in a heat pipe.So I need to simulate two situations including the moving interface and the stable one.
My English is very poor,and I hope that you will not have some troubles in understanding my words.

Does it mean that you also have temperature effects (heat pipe)?
The methods you use to simulate a moving and a stationary interface are not different. A stationary interface is nothing more than a special case of a moving interface.
Still I do not really get what you really want to do. You should provide more details. Otherwise, we cannot help you.

Timm

Maybe I understand little about the LBM ,so I will read the LBM book again,and then come back for help.
Thanks a lot.

HI NASH,

did you find any solution for your problem please?

Thank you