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Solution Control: is my equation need a symmetry, assymetric or diagonal solver?

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Old   October 19, 2015, 12:56
Default Solution Control: is my equation need a symmetry, assymetric or diagonal solver?
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Matt
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I am trying to use the correct solvers within fvSolution. However, I could use some help determining whether asymmetric, symmetric, or diagonal solvers should be used.

Here is the solver equation:
Code:
fvVectorMatrix UEqn
(
      fvm::ddt(U)
    + fvm::div(phi, U)
    - fvm::laplacian(nu, U)
    ==
      flowDirection*gradP
);

solve(UEqn == -fvc::grad(p));
where gradP is a quantity provided by the user.

Also, under what conditions would you already know the lower diagonal, upper diagonal, or both? From my basic education in CFD, I have only known solution matrices where the diagonals are the only known elements.
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Old   October 20, 2015, 05:14
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Nima Samkhaniani
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i guess it is asymmetric matrix, however use easy method !!! try and error.
you can assign asymmetric matrix for example PBICG if it does not work, change it
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Old   October 21, 2015, 22:04
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Quote:
Originally Posted by nimasam View Post
i guess it is asymmetric matrix, however use easy method !!! try and error.
you can assign asymmetric matrix for example PBICG if it does not work, change it
LOL! Yea, I read in the online documentation that it would let you know if it was wrong. I was hoping to get a little more insight into the matter though
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