in fluid in all slices becoming greater than a threshold value (or negative). Can someone please explain what this means, i.e. when this happens ? Could it have anything to do with the meshing ? I use NEX_XI =192 and NPROC_XI = 3, so as to engage 54 processors. Thanks, Arjun -- Arjun Datta PhD (Geophysics) candidate University of Cambridge Bullard Laboratories