[JD_PM]

Hi everyone!

I am a master student who is going to do a numerical master thesis about two-phase cavitating flows in cryogenic conditions (we will work with liquid nitrogen actually) using OpenFOAM.

I have never used OpenFOAM before. This is my first post but will certainly be not the last!

I already downloaded OpenFOAM (v9, summer 2021) and I run Linux via virtual box.

I am looking at the documentation, to see the already available solvers related to two-phase cavitating flows in cryogenic conditions, and all I can find is CavitatingFoam (applications/solvers/multiphase/CavitatingFoam/CavitatingFoam.C)

The cavitatingFoam solver is a transient cavitation solver that employs the HEFM approach to capture phase-change in isothermal, compressible cavitating flows. Its main assumptions are:

1) The fluid is treated as a homogeneous mixture; flow properties are weighted by a vapor phase fraction field that takes values between 0 (fully liquid) and 1 (fully vapor).

2) A barotropic equation of state is used to couple density and pressure variations, and to close the system of governing equations.

3) Liquid and vapor phases are in kinematic and thermodynamic equilibrium: velocity and temperature differences between phases are neglected, and the energy conservation equation is not solved.

Given that we are going to work with two-phase cavitating flows in cryogenic conditions (non isothermal process), neither 1) nor 2) hold.

I read the following paper "Development and validation of a homogeneous flow model for simulating cavitation in cryogenic fluids" by Saeed Rahbarimanesh, Joshua Brinkerhoffa and Jim Huang (not possible attachment).
They modified the cavitatingFoam solver so that cryogenic cavitation is captured. They coupled with cryogenic forms of the mass and momentum conservation equations to ensure that non-equilibrium processes, including latent heat transfer, were included.

I did not find the actual solver in OpenFOAM. However, the code seems to be here https://github.com/okcfdlab/compress...ses/tag/v1.0.0

So to summarize: might you please guide me to find all solvers at OpenFOAM related to two-phase cavitating flows (do not need to be cryogenic; the aim of the work is to find all available solvers and see how can we use/modify them to write our own).

Thank you!

[JulioPieri]

Hi! So, have a look at /opt/OpenFOAM/<yourOFversion>/applications/solvers .

This solver you referenced seems to be very custom, thus not available from regular OF installation. I think what you are looking for is how to compile a custom solver, then you could compile this particular solver you shared.

[JD_PM]

Thank you for your reply, I will try to compile such solver.

Let me address a (basic) issue connected to my original post. In my search of solvers, I came across "interPhaseChangeFoam" via website (https://www.openfoam.com/documentati...fcbf8d2aa.html). I go to applications/solvers/multiphase; in multiphase I am supposed to find a folder called "interPhaseChangeFoam" but I don't have it.

I downloaded the OpenFOAM v9 Summer 2021 version. How to incorporate "interPhaseChangeFoam" folder to my version of OpenFOAM?

Thanks for your time.

[JulioPieri]

Weird, I have it here. Are you in the right directory?

/opt/OpenFOAM/[youversion]/applications/solvers/multiphase

If you are, try recompiling openfoam, maybe you're missing some features.

[JD_PM]

I am in the multiphase directory indeed but as you can see (https://ibb.co/Xszn6SG), it is not there...

Let me ask, what do you mean by "recompile"? This is what I did to compile OpenFoaM in the first place https://www.youtube.com/watch?v=6IbPYQMXDfk&t=188s

[Yann]

Hi guys,

interPhaseChangeFoam existed up to OpenFOAM-8 but it is not in OpenFOAM-9 anymore, as you can see on gitHub:

• OpenFOAM-8: multiphase solvers
• OpenFOAM-9: multiphase solvers

The developers at the OpenFOAM foundation have put a lot of work into rationalising the code and combining solvers so I bet interPhaseChangeFoam has been deprecated and combined to another existing solver.
After a quick look at the code, it could have been integrated in compressibleInterFoam since the "twoPhaseChangeModel" initially in interPhaseChangeFoam are now in compressibleInterFoam.

I'm just guessing here, I do not use these solvers so you will have to look for it yourself.

@JD_PM: be careful to not confuse the different variants of OpenFOAM:

• OpenFOAM foundation branch: openfoam.org, the latest release is OpenFOAM-9
• ESI-OpenCFD branch: openfoam.com, the latest release is OpenFOAM-v2112

If you are using OpenFOAM-9 you should stick to the documentation on openfoam.org. If you look at the documentation on openfoam.com, be aware there could be quite significant differences with the version you are using (syntax, available models and solvers, etc...)


Cheers,
Yann

[JD_PM]

Hi Yann.

Thank you for your very helpful reply.

I did not know about such distinction in OpenFOAM. I use OpenFOAM-9. I was mainly checking ESI-OpenCFD branch's API guide (https://www.openfoam.com/documentati...api/index.html), which I find interactive and comfortable to go through. I will investigate OpenFOAM foundation branch's website then.

In contrast to interPhaseChangeFoam, compressibleInterFoam is compressible and non-isothermal so they differ quite a bit. Actually, this discussion is related to my other thread here: Comparing CavitatingFoaM​ and InterPhaseChangeFoaM solvers (code). I will read further and then post, thank you again!

[Sofy]

Hello!
I already installed OF10 and I want to compile ZGB to use in interFoam. However, I noticed that twoPhaseChange folder that contains cavitation models is now inside compressibleInterFoam. Could you please tell me how should I compile ZGB to use with interFoam?