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January 27, 2012, 00:07 |
2D and 2D axis difference
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#1 |
New Member
Qi Guan
Join Date: Aug 2011
Posts: 27
Rep Power: 14 |
I have a euler-solver code, structured grid. It works for 2D. I want to change it to 2d axisymmetric. I've changed the associated volume and face area and source term coming along with axisymmetric.
But there's still problem in it. Is there anything else I should do? Thank you. |
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January 27, 2012, 01:59 |
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#2 |
Senior Member
Martin Hegedus
Join Date: Feb 2011
Posts: 500
Rep Power: 19 |
Source term?
You'll need to change the fluxes (RHS) in the j (theta direction) along with the required implicit stuff on the LHS (if you are doing implicit). For the RHS you have a flux term (which does not exist in 2D) in the theta direction along the lines of p*A(j+1)-p*A(j-1) but A(j+1)-A(j-1) can be reformulated as -(A(i+1)-A(i-1)+A(k+1)-A(k-1)). Or something along those lines. That was for central differencing. That, along with changes in area and volume, should be enough. I believe... |
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January 27, 2012, 02:02 |
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#3 |
Senior Member
Martin Hegedus
Join Date: Feb 2011
Posts: 500
Rep Power: 19 |
Oh, one more very important thing. Unlike 2D, your CFL number MUST take into account the theta direction. I usually use a 5 degree wedge to calculate CFL.
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