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Old   January 8, 2014, 06:42
Default Convergence
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amir
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hi,
I have a question...
how can I converge an equation with just a convection term?
I don't have any diffusion and unsteady and source terms...
does it have any specific discretization?
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Old   January 8, 2014, 08:27
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Marc
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Can you describe in more detail what it is that you are trying to do?
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Old   January 8, 2014, 11:17
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Originally Posted by laingmj View Post
Can you describe in more detail what it is that you are trying to do?
I use a finite volume code, in the species equation with the simplification I just have a convection term and it is equal to zero.
In this situation my code is running to diverge.
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Old   January 8, 2014, 11:49
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Filippo Maria Denaro
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Quote:
Originally Posted by amirmohammad View Post
I use a finite volume code, in the species equation with the simplification I just have a convection term and it is equal to zero.
In this situation my code is running to diverge.

Is that something like Div (rho*V) =0 ? that is a constraint, must be satisfied coupling it to the other equations.
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Old   January 8, 2014, 11:57
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Quote:
Originally Posted by FMDenaro View Post
Is that something like Div (rho*V) =0 ? that is a constraint, must be satisfied coupling it to the other equations.
It is Div (rho*U*C)=0.0

C is the concentration of species.
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Old   January 8, 2014, 12:02
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the key is the same, the convergence of the solution is obtained while solving a system of equations, you can not focus only on this single equation
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Old   January 8, 2014, 12:05
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Originally Posted by FMDenaro View Post
the key is the same, the convergence of the solution is obtained while solving a system of equations, you can not focus only on this single equation
I have 5 equations

1) u momentum
2) v momentum
3) pressure correction
4) oxygen concentration
5) water concentration

in water concentration I just have a convection term as follow:
Div ( rho*U*C) = 0.0
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