[metro]

Hey All,

I am currently working on a side project were I need to determine the phase concentrations in a storage tank. The main aim is to:

- Determine "dead zones" in the tank where there is a high phase concentrations.

- Determine the location of baffle or weirs.

The tank is filled from the top and has a discharge at the bottom.

Is there a standard OF solver which I can use or do I need to use something like simpleFoam and incorporating a scalar transportation function? Any suggestions will be greatly appreciated?

[alberto]

Originally Posted by metro

Hey All,

I am currently working on a side project were I need to determine the phase concentrations in a storage tank. The main aim is to:

- Determine "dead zones" in the tank where there is a high phase concentrations.

- Determine the location of baffle or weirs.

The tank is filled from the top and has a discharge at the bottom.

Is there a standard OF solver which I can use or do I need to use something like simpleFoam and incorporating a scalar transportation function? Any suggestions will be greatly appreciated?

It looks like a multiphase problem more than a scalar transport problem. If understand it correctly, you want to see how the fluid distributes in an originally empty tank. Assuming this is correct, you might want to use a VOF approach (interFoam and friends).

Best,

[metro]

Thank you for the reply Alberto,

The tank is partially full and during its operation fluid will be continuously added or removed depending on the concentration levels in the tank. This is mainly for a waste water treatment plant. Therefore I would like to determine dead zones and the concentration profile along the tank. I hope this clarifies things more?

Can another approach be using the twoPhaseEulerFoam solver?

[alberto]

Originally Posted by metro

Thank you for the reply Alberto,

The tank is partially full and during its operation fluid will be continuously added or removed depending on the concentration levels in the tank. This is mainly for a waste water treatment plant. Therefore I would like to determine dead zones and the concentration profile along the tank. I hope this clarifies things more?

No it does not clarify that much, sorry :-)
How do you distinguish the two fluids? Do they have different composition? Please explain your problem in detail, or it is a challenge to give a meaningful answer, trying to guess!

[metro]

That is fine and my apologies if the description is too vague.

What we have is a very large tank which contains oxidized water which is used for biological processes. Oxidized water is then pumped into the tank to maintain the oxygen in the water. Water is also pumped out of the tank depending on the process requirements. What we need to do it determine the levels of oxygen in the tank which is related to the flow pattern in the tank. We need to determine "dead zones" in the tank as these are areas are where the water is deemed stale. Does this make more sense?

[alberto]

Yes, it's clear now. You have to add a scalar transport equation for the oxygen concentration, and code it so that the scalar is transported only inside the phase.

In other words, in general (in the code you have to write it consistently with the rest of the implementation):

ddt(alpha*rho*C) + div(alpha*rho*C*U) = 0

Best,
Alberto