CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM Programming & Development

MHD Shocktube test

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Display Modes
Old   November 20, 2015, 10:34
Default MHD Shocktube test
  #1
New Member
 
Ved Mukherjee
Join Date: Nov 2015
Posts: 2
Rep Power: 0
vedlk is on a distinguished road
Hello, I have made a solver by merging the sonicFoam and mhdFoam.The B magnetic field density vector is coupled with rho to form compressible equation but the graph shows high oscillations and pressure and velocity graph is still the same,though I have added the magnetic terms in the equation. Can anybody explain me the reason behind these problems.
vedlk is offline   Reply With Quote

Old   November 22, 2015, 09:11
Default
  #2
Super Moderator
 
Bruno Santos
Join Date: Mar 2009
Location: Lisbon, Portugal
Posts: 9,748
Blog Entries: 39
Rep Power: 103
wyldckat is a glorious beacon of lightwyldckat is a glorious beacon of lightwyldckat is a glorious beacon of lightwyldckat is a glorious beacon of lightwyldckat is a glorious beacon of light
Quote:
Originally Posted by vedlk View Post
Can anybody explain me the reason behind these problems.
Quick answer: I would actually like to try and explain this, but I can't figure out what exactly is going on from your description
Please follow the instructions given here: http://www.cfd-online.com/Forums/ope...-get-help.html

Quote:
Originally Posted by vedlk View Post
but the graph shows high oscillations and pressure and velocity graph is still the same
I can't figure out if the high oscillations graph is the B field or not, or if it's residuals... or whatever it is exactly
wyldckat is offline   Reply With Quote

Old   November 25, 2015, 04:14
Default
  #3
New Member
 
Ved Mukherjee
Join Date: Nov 2015
Posts: 2
Rep Power: 0
vedlk is on a distinguished road
The graph is of B field. The pressure and velocity graphs are still the same as Euler's equations. I am asking what should I change ? Piso algorithm or something else
vedlk is offline   Reply With Quote

Old   November 28, 2015, 14:24
Default
  #4
Super Moderator
 
Bruno Santos
Join Date: Mar 2009
Location: Lisbon, Portugal
Posts: 9,748
Blog Entries: 39
Rep Power: 103
wyldckat is a glorious beacon of lightwyldckat is a glorious beacon of lightwyldckat is a glorious beacon of lightwyldckat is a glorious beacon of lightwyldckat is a glorious beacon of light
Hi vedlk,

I've taken a look into the two solvers and it is indeed possible that you might have confused something in the merger of the two solvers.
The last version of OpenFOAM to have sonicFoam in PISO form is 2.1.x: https://github.com/OpenFOAM/OpenFOAM...am/sonicFoam.C

As for the B graph, I guess you are referring to the residuals plot? If so, then it is possible that there was an implementation problem when merging the two solvers.

If you are referring to the B field itself, i.e. the results, it's possible that the results for the B field might actually make sense, depending on how the flow profile is going in the sonic range, because a very high pressure or high turbulence region can have significant impact on the electromagnetic profiles, since I can only imagine that the molecules do not take any specific orientation that would lead to a common magnetic orientation.

If using the sonicFoam from 2.1.x as a basis still gives you the same results/problems, then please follow the instructions given here: http://www.cfd-online.com/Forums/ope...-get-help.html

Best regards,
Bruno
__________________
wyldckat is offline   Reply With Quote

Old   June 13, 2016, 01:08
Default How to get the result after we run the MHD case in tutorial folder.
  #5
New Member
 
mohd nor hazwan bin hadzir
Join Date: May 2016
Posts: 8
Rep Power: 2
M.N Hazwan Hadzir is on a distinguished road
hello everyone,

i am new in OpenFoam user.
I have problems in producing result in MHD case. how i can take out the result data n graph from the simulation?
anybody can help me .
M.N Hazwan Hadzir is offline   Reply With Quote

Reply

Tags
graph result, mhd problem, result file

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
A new test harness for OpenFOAM mbeaudoin OpenFOAM Announcements from Other Sources 0 June 17, 2010 10:36
critical error during installation of openfoam Fabio88 OpenFOAM Installation 21 June 2, 2010 03:01
OF 1.6 | Ubuntu 9.10 (64bit) | GLIBCXX_3.4.11 not found piprus OpenFOAM Installation 22 February 25, 2010 14:43
Problems in compiling paraview in Suse 10.3 platform chiven OpenFOAM Installation 3 December 1, 2009 08:21
benchmark test case for MHD RT instability cou Main CFD Forum 0 May 7, 2007 09:38


All times are GMT -4. The time now is 08:03.