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-   -   Jacobian of NS equation (http://www.cfd-online.com/Forums/su2/117991-jacobian-ns-equation.html)

Mojtaba M May 18, 2013 18:57

Jacobian of NS equation
 
Dear SU2 developers

My question is about the projected Jacobian of NS equation as is calculated in function "CNumerics::GetViscProjJacs" I derived the very same expressions except from the length of edge vector in the denominator of all elements of Jacobian matrix. Could you please explain where this term came from?

I wonder if it is possible to have some more detailed references about the formulation used in different parts of the code other than what is cited in the website and the paper AIAA 2013-0287.

fpalacios May 27, 2013 21:28

Quote:

Originally Posted by Mojtaba M (Post 428483)
Dear SU2 developers

My question is about the projected Jacobian of NS equation as is calculated in function "CNumerics::GetViscProjJacs" I derived the very same expressions except from the length of edge vector in the denominator of all elements of Jacobian matrix. Could you please explain where this term came from?

I wonder if it is possible to have some more detailed references about the formulation used in different parts of the code other than what is cited in the website and the paper AIAA 2013-0287.

Hi,

The length of the edge is a key element that you obtain when you estimate the normal gradient as $\partial_n U = (U_i - U_j) / (x_i - x_j)$. This simplification is used to evaluate the first order Jacobian (instead of Green-Gauss or LS).

Cheers,
Francisco


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