Simulating Water and Air mixture

[Carl_mgfx]

Good day all

This may seem like a stupid question up front, but please keep in mind that I have no experience with CFD software.

I am actually asking this on behalf of a customer.  He wants to know if there is any software that can simulate a water and air mixture passing through a coiled pipe?

So in essence he needs to simulate the transmission of a mix of a compressible and un-compressible fluid.

Thanks for your time.

[OmkarJ · Accepted solution]

I do not think Autodesk CFD has a capability to simulate the fluids having significant difference in the density. Hoever, other comnmercial softwares (ANSYS FLUENT/CFX, Star CCMetc), along with open source OPEN FOAM do have multiphase capabilities. 

However, simulating these correctly and successfully is quite tricky and requires a hands on experience with multiphase simulations. 

OJ

[apolo_vanderberg]

Carl,

 SimCFD can model free surface effects of liquid in the pipe.

However at this time we do not model the gas side when doing free surface, such that the gas side for Free surface does not contain any real properties (if we were using free surface model to fill a sealed tank, we would not see the pressurization/compression of the gas in the tank)

[Carl_mgfx]

Thanks for the replies

@ apolo

I have seen the free surface modeling, but in this case I think it's more of a mixure, almost like aerated water.  There would be no definite seperation between two volumes, more of a homogenous mix.

[OmkarJ · Accepted solution]

What is the volume fraction of air? If it is too small (less than 10%) the water bubbles will be very small, and you might just be able to use Lagrangian massed particle traces, by representing water bubbles as particles, to have at least some representation. 

However if the air volume fraction is larger, it is a case of Euler-Euler multiphase modelling, not free-surface modelling. From what I read, 2014 doesn't have Euler-Euler multiphase models. 

OJ

[Carl_mgfx]

Thanks for the input OJ.

I will check with my customer what % air-water mixture he wants to pass through the pipes and I'll get back to you.