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-   -   u_f , u, are these two the same? (http://www.cfd-online.com/Forums/openfoam-programming-development/123548-u_f-u-these-two-same.html)

sharonyue September 16, 2013 04:20

u_f , u, are these two the same?
 
Hi guys,

Wonderful day!

While Im digging into fvc::reconstruct(), after lots of effort, I made a little progress, Now Im confusing that:
\sum {{n_f}\left( {{S_f} \cdot u} \right)}  = \sum {{n_f}\left( {{S_f} \cdot {u_f}} \right)}

namely:
u_f = u

Is this rite? Only by this I can get the same equation as fvc::reconstruct().

Bernhard September 16, 2013 04:41

Can you add some linenumbers of relevant files? u and u_f are definitely not the same, as one would be a surface field and the other a volume field.

sharonyue September 16, 2013 04:46

Quote:

Originally Posted by Bernhard (Post 451949)
Can you add some linenumbers of relevant files? u and u_f are definitely not the same, as one would be a surface field and the other a volume field.

I will make it more clear later, texting these equations in mathtype is time-consuming. Thank you very much. U help me alot...

sharonyue September 16, 2013 19:37

Sorry, so late!

\begin{array}{l}
\sum {{n_f}\left( {{S_f} \cdot u} \right) = } \sum {{n_f}\left( {{S_f} \cdot {u_f}} \right)} \\
\sum {\left[ {\left( {{n_F} \otimes {S_f}} \right) \cdot u} \right]}  = \sum {\frac{{{S_f}}}{{\left| {{S_f}} \right|}}} \left( {{S_f} \cdot {u_f}} \right)\\
\sum {\left[ {\left( {\frac{{{S_f}}}{{\left| {{S_f}} \right|}} \otimes {S_f}} \right) \cdot u} \right]}  = \sum {\frac{{{S_f}}}{{\left| {{S_f}} \right|}}} {\phi _f}\\
u = \underbrace {{{\left\{ {\sum {\left[ {\left( {\frac{{{S_f}}}{{\left| {{S_f}} \right|}} \otimes {S_f}} \right)} \right]} } \right\}}^{ - 1}} \cdot \sum {\frac{{{S_f}}}{{\left| {{S_f}} \right|}}} {\phi _f}}_{weller's\;fvc::reconstruct()}
\end{array}

this might be clear. Any ideas?

sharonyue September 22, 2013 21:01

any ideas?


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