CFD Online Logo CFD Online URL
Home > Forums > Main CFD Forum

Jamesonís artificial dissipation in Euler Eq's

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

LinkBack Thread Tools Display Modes
Old   April 4, 2005, 07:51
Default Jamesonís artificial dissipation in Euler Eq's
Posts: n/a
Dear Friends,

I am trying to simulate the flow field over a 2d bump, i.e. 2d Euler equations. I have a question that how should I calculate the artificial dissipation terms on the first two rows of the cells near the wall (especially the first row over the wall). Also I need the value of the pressure on the wall for boundary condition, is it possible to extrapolate the unknown wall pressure from inside the field?

Your attention and help will be highly appreciated,

With the best regards,

F. Jam
  Reply With Quote

Old   April 8, 2005, 18:03
Default Re: Jamesonís artificial dissipation in Euler Eq's
Posts: n/a
I have used the Jameson-Swanson-Turkel scheme in a finite volume formulation, and I implemented the bc by rows of extra cells: the internal cell were updated by Runge Kutta, and then the extra cell were changed imposing the BC., thus, the extra cells don't require any spatial derivation, while for the row of cells adiacent to the extra cells I simply didn't introduce the dissipation term. It worked fine. For the pressure into Eulerian field, just update it by dp/dr=rho*Vt^2/r. This equation is exact, But many times the extrapolation is good as well. Hope this can help
  Reply With Quote

Old   April 9, 2005, 10:52
Default Re: Jamesonís artificial dissipation in Euler Eq's
Posts: n/a
Dear Sir,

Thanks for your comments. I wrote my code. But it does not work because in about 50 first iterations it diverges. I applied two ghost cells below the lower wall and two above the upper wall, also two before the inlet and two after outlet for calculating artificial dissipation terms. But for pressure on the wall I used extrapolation. My inlet boundary condition is supersonic. And outlet also is supersonic. So for inlet I set free stream values for my conservative variables and for the outlet I used extrapolation from the field. I do no know where is my mistake I checked my code many times but it does not converges at all. If you have a FVM code in FORTRAN for this problem (flow in a channel over a circular bump) would you send it for me please?

With the best regards,

F. Jam,
  Reply With Quote


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
About Preconditioning Euler eqs. convergence Rake Main CFD Forum 7 July 1, 2015 06:45
Artificial dissipation for NS equations, flow in a pipe RameshK Main CFD Forum 8 November 13, 2011 11:29
Artificial Dissipation TheBoyce Main CFD Forum 2 March 23, 2011 16:27
Artificial Dissipation Fereidoun-e-Jam Main CFD Forum 3 April 10, 2005 22:16
Artificial Dissipation Fereidoun-e-Jam Main CFD Forum 0 April 6, 2005 07:33

All times are GMT -4. The time now is 17:31.