[Gfs-devel] Problem with gfs_face_interpolated_value_generic OR gfs_variable_from_name ?

[Manoj Kumar Tripathi]

Hi developers,

I have been recently trying to test the face interpolated values of velocity and I found that GFS_VALUE doesn't give the correct answer.

Inside GfsInit, at every time step (istep = 1),  I am finding the face interpolated values as follows:
FttCellFace face1;
GfsVariable *uvar = gfs_variable_from_name(GFS_DOMAIN(sim)->variables,"U");
face1 = ftt_cell_face(cell,FTT_LEFT);
double u_lf =  gfs_face_interpolated_value_generic(&face1,uvar);
face1 = ftt_cell_face(cell,FTT_RIGHT);
double u_rf =  gfs_face_interpolated_value_generic(&face1,uvar);

and then, to check the accuracy of these interpolations, I am subtracting U from (u_lf + u_rf)/2.0, but this is not coming out to be zero. U is of the order of 1e-3 and interpolated values are of the order 1e-5. This is puzzling me a lot. I have this part of the code just before OutputSimulation.  Can anyone sort this out for me?

Thanks.

--

Manoj Kumar Tripathi

ma...@iith.ac.in