CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   Main CFD Forum (http://www.cfd-online.com/Forums/main/)
-   -   problems with simple algorithm(by patankar) (http://www.cfd-online.com/Forums/main/67577-problems-simple-algorithm-patankar.html)

 jav1984 August 19, 2009 12:18

problems with simple algorithm(by patankar)

I have some questions about SiMPLE algorithm based on Patankar's book.
on page 123 step 2 of algorithm:solving u* and v*(for 2D problem).to writing a fortran
code for this algorithm I have a confusing problem.if we note at eq. 6.8 & 6.9 the nodes that
are involved in two equations are not the same!(because the first eq is
written for sataggerd grid at x direction,the second is at y directin)
for example in the coefficient aE(for solving ue)there is FE=rho*uE(u*E)
we konw that UE is velocity in main point that is not calculated in this
eq.shoud I interpolate UE=0.5*(ue+uc)?
2-in coefficient aN there is Fb=rho*Vb,my outcome(guess)is:(vb is unknwon which should be guessed at the first
and after solving u*,we should enter the coefficient of anb based on
calculated v*,then use these V* adgain for coeficeint u* and repete
this to converge).is my guess(the sentence in pranteses) true? if it is true
we know that the nodes that their velocity entered in these two eq are
not the same! what shoud I do?
3-how should I apply boundary condition for staggered grid?(for example
at enterance we know velocity for main point)
4-if we have a solid in our domain shoud we define gamma as an array or as a parameter?
(we should attribute gamma=infinity for solid )