General

General

POLYFLOW – zero pivot for the PRESSURE (triangles and tetrahedra along boundaries)

    • FAQFAQ
      Participant

      The calculation terminates with the error message “zero pivot for the pressure”. It usually happens on a mesh involving triangles and tetrahedra along boundaries. When using a mesh which contains triangles (in a 2D geometry) or tetrahedra (in a 3D geometry), one must take care that all elements have at least one node in the interior of the domain. This is especially true when boundary conditions are imposed in terms of velocities, where most equations for the pressure reduce to 0=0 and a zero pivot is generated for the pressure unknown.