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July 1, 2013, 08:57 |
Solution changing with dt.
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#1 |
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Hi,
I have a code in cylindrical coordinates that uses central differences. My problem is this: when I change the time step size, keeping everything else the same(grid included), I get vastly differing solutions. Been breaking my head over this - any ideas?? Thanks in advance! |
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July 1, 2013, 11:21 |
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#2 |
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cfdnewbie
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Are you talking about a steasy state problem or an unsteady one?
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July 2, 2013, 01:01 |
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#3 |
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Its a steady state problem.
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July 2, 2013, 03:18 |
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#4 |
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cfdnewbie
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Are you using an implicit or explicit solver for this?
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July 2, 2013, 04:25 |
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#5 |
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Advection terms are explicitly calculated. Viscous terms in the radial direction alone are implicitly calculated.
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July 2, 2013, 05:09 |
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#6 |
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Filippo Maria Denaro
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I think that the discussion of your problem must be better focused:
- what variable you see that strongly change with dt? - what about the cell Re number? are you sure to fulfill the stability constraint? - have you experienced the same behavior for refined h steps? |
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