CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   Main CFD Forum (http://www.cfd-online.com/Forums/main/)
-   -   Interpolation for ghost cell help (http://www.cfd-online.com/Forums/main/10967-interpolation-ghost-cell-help.html)

zonexo March 11, 2006 20:03

Interpolation for ghost cell help
 
hi,

i am trying to use interpolation to get the pressure value of the ghost cell. I have dp/dn=0 at a location (boundary) and a few other pressure values at the neighbouring nodes.

my method is to use linear interpolation where p=a0+a1*x+a2*x2 at 2 neighbouring nodes. to use the dp/dn=0 condition, i differentiate the eqn to give dp/dn=a1*dx/dn+a2*dy/dn. a 3X3 matrix is formed and its inverse is computed to get a0,a1 and a2. Similar method can be used for bilinear and quadratic interpolation.

however, the problem is that the matrix can be singular at times.

Is there a better interpolation method which makes use of these conditions and yet it is stable?

Thank you!



All times are GMT -4. The time now is 17:37.