[pumpkinITER]

In short, I'm looking to add in a magnetic field component to the rhoCentralFoam solver.

The simulation I'm running is supposed to represent a high temperature and pressure (5 eV, 300 MPa) plasma expanding out of a small cavity. I have run the simulation with just rhoCentralFoam, and now want to see the effect of running the same simulation if an external magnetic field is applied. I'm thinking that I'll be combining elements of rhoCentralFoam and mhdFoam.

Are there any good tutorials for this?

I've already seen "How to add temperature to icoFoam", but I think I need much more than that.

Thanks!

[Alexee]

Originally Posted by pumpkinITER

In short, I'm looking to add in a magnetic field component to the rhoCentralFoam solver.

The simulation I'm running is supposed to represent a high temperature and pressure (5 eV, 300 MPa) plasma expanding out of a small cavity. I have run the simulation with just rhoCentralFoam, and now want to see the effect of running the same simulation if an external magnetic field is applied. I'm thinking that I'll be combining elements of rhoCentralFoam and mhdFoam.

Are there any good tutorials for this?

I've already seen "How to add temperature to icoFoam", but I think I need much more than that.

Thanks!

I'm working on a similar problem. Initially I went with sonicFoam and added magnetic field into it, nut now I'm switching to density-based solver. I didn't use a lot of literature aside from the link you've provided, but I only needed to add constant magnetic field from a coil, so I just wrote a script to calculate in each cell using writeCellCentres.

I just realized that your post is dated February^^. Have you succeded in modifying rhoCentralFoam? If so, maybe you can share your experience or, if not, I can probably answer some of your questions.

[chriss85]

Any updates here?
I'm also somewhat interested in adding new terms to rhoCentralFoam. I'm currently using sonicFoam, but I think that rhoCentralFoam might be better.

Do you happen to know how low the MACH number may be with rhoCentralFoam to keep it stable and reliable? Because in plasmas the speed of sound can be considerably higher than in air, so we can have subsonic cases even when the flow is a few thousand metres per second.

[Alexee]

Originally Posted by chriss85

Any updates here?
I'm also somewhat interested in adding new terms to rhoCentralFoam. I'm currently using sonicFoam, but I think that rhoCentralFoam might be better.

Do you happen to know how low the MACH number may be with rhoCentralFoam to keep it stable and reliable? Because in plasmas the speed of sound can be considerably higher than in air, so we can have subsonic cases even when the flow is a few thousand metres per second.

Hey, I've succeded to some extent in adding e/m interaction into rhoCentralFoam. My problem has constant magnetic field, so all I had to do is calculating Lorenz force as a function of velocity.

Using upwind schemes for interpolation helped me to keep rhoCentralFoam stable. (vanLeer schemes, that are used in shockTube tutorial caused the solver to crash on my problem (mach=3)).
rhoCentralFoam is better than sonicFoam in that it doesn't cause overshooting in shockwave like the sonicFoam does. I'd show you exactly what I mean by that, but I'm not at work till Monday. Basically the pressure in the shock wave from has to be monotone, but with sonicFoam (as with all pressure-based solvers, as opposed to density-based) it has a spike, which is essentially non-physical.

[chriss85]

You are at supersonic speeds though with MACH=3, at which density based solvers outperform pressure based solvers like sonicFoam. Have you made sure to use the correct speed of sound? In plasmas it can be significantly higher due to the high temperature.

[mechesanjiv]

Hello all above,

May I know where should I scroll to get the idea to incorporate mhdFoam into one of the density based solver or in rhoCentralFoam as discussed above? I have setup a density based solver but I am stuck in evaluating the magnetic field effect in it!!
Please reply me in your free time..

Thanks,