Hi Michael, I think this paper explains the issue better than I can,
https://www.researchgate.net/publication/263972969_ANALYSIS_OF_THE_NON-ORTHOGONALITY_CORRECTION_OF_FINITE_VOLUME_DISCRETIZATION_ON_UNSTRUCTURED_MESHES Figure 2 shows the control volume and Figure 3 shows the skewness issue. Cheers, Daniel On Wed, Jul 20, 2016 at 4:30 PM, Michael Waters <waters.mik...@gmail.com> wrote: > Hi, I'm not sure I understand the issue. Maybe you could explain more? I > made a diagram to help. > > Cheers, > > -Mike Waters > > > > On 07/20/2016 02:51 PM, Daniel Wheeler wrote: >> >> FiPy has issues with non-orthogonal meshes (i.e. when the vector >> between the cell center isn't parallel to the face normal). We did >> make an attempt at fixing this, which resulted in two diffusion terms, >> >> >> https://github.com/usnistgov/fipy/blob/develop/fipy/terms/diffusionTermCorrection.py >> >> and >> >> >> https://github.com/usnistgov/fipy/blob/develop/fipy/terms/diffusionTermNoCorrection.py >> >> As I recall, the "corrected" diffusion term was quite unstable for >> moderate to high non-orthogonality. >> >> I'd like to address this issue again and I was wondering if anyone had >> opinions regarding the latest / best / most tractable approach for >> dealing with non-orthogonality in CC-FV. I haven't followed the >> literature on this for quite some time. >> > > > _______________________________________________ > fipy mailing list > fipy@nist.gov > http://www.ctcms.nist.gov/fipy > [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ] > -- Daniel Wheeler _______________________________________________ fipy mailing list fipy@nist.gov http://www.ctcms.nist.gov/fipy [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ]