For a solid-liquid flow (sand and water), do I need to set a solid domain and a fluid domain, then connect them with domain interface? If so, which material group should I put the material "sand" so that I can select it in solid list?

Sorry, I misunderstand the definition of domain. Now I set the material "sand" and "mixture" (sand, water)in user group. In fluid domain, what is the different to select " mixure" and to select Sand and Water separately at fluid list?

Hi,

What are you trying to do? Does the sand get moved around by the fluid or is it stationary like at the beach and the water flows on top of it?

I think you are trying to model sand being moved by the fluid. This is called Lagrangian particle tracking and there is an example in the tutorials.

Glenn Horrocks

Yes, I am trying to model sand being moved by the fluid. What I have to do is to find the minimum velocity of fluid in order to suspend the sand where the sand is initailly deposited at the bottom of the pipe.

Hi,

In that case then look in the documentation for Lagrangian particle tracking. There is also a tutorial example - I think it is the butterfly valve example.

Glenn Horrocks

Thanks,

I have done the tutorial, but the case is describing fully suspensed sand moving by water. How can I set the sand from stable state (sediments) to suspension state?

Hi,

You cannot do that sort of simulation in CFX. You need a discrete particle model to capture the packing of the sand and the release of particles. Have a look at EDEM:

http://www.leapaust.com.au/products/details/edem.htm

Glenn Horrocks

Direct link: http://www.dem-solutions.com/