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-   -   conservative, non conservative form???? (http://www.cfd-online.com/Forums/main/10994-conservative-non-conservative-form.html)

vijesh joshi March 15, 2006 08:30

conservative, non conservative form????
 
hello friends, I understood how the basic 3 governing eqns can be obtained in conservative and non conservative form. but i got a question that why the eqns have to be obtained in these forms? plz reply

al March 15, 2006 09:21

Re: conservative, non conservative form????
 
Eqs in conservative and non conservative forms are mathematically equivalents. The point is that some numerical methods such as Finite Volume types are developed based on the conservative form. In this way, these numerical algorithms force the conservation of the total flux. Other methods such as Finite Difference types consist in getting an approximation of the equation independent of the form.

In general, independent of the numerical method and form of the equation you should get the same solution.

vijesh joshi March 15, 2006 13:26

Re: conservative, non conservative form????
 
FVM are based on conservative form you said. why not non conservative???????

Mohamed March 15, 2006 22:40

Re: conservative, non conservative form????
 
Dear Vijesh..

In Finite Volume Method we are integrating the Gov. equations for each CV throughout the domain. So it directly utilizes the conservation. In Finite Difference we have to confirm the conservation. I mean we have to prove there is no loss and No gain of any of mass, mom and energy.

In finite Volume Method, At interface, flux coming from left CV is equal to going to Right CV.in the same way top and bottom . so fluxes at each CV cancel each other. Finally it arises the Only Boundary conditions and whole domain acts as a single CV.

I hope it will help Regards Mohammed

vijesh joshi March 16, 2006 00:10

Re: conservative, non conservative form????
 
Thank you Mohamed.


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