It is used for large amplitude free surface sloshing in a rigid tank subjected to a vertical or horizontal ground motion. In this case, only fluid nodal y-coordinates are updated after each iteration according to the free surface new location.
1-5 Vertical pattern first node (NS ) 6-10 Vertical pattern last node (NE ) 11-15 Vertical pattern nodal increment (INC ) 15-20 Vertical pattern number of repetitions (IREP ) 21-25 Vertical pattern increment (INCP )