L(W895)
TEXT(WATER DISPLACED BY AIR FROM ABOVE  :W894
TITLE
  DISPLAY
  Case 894 is similar to case 895; but the air supply is at the top
  of the pipe rather than at the bottom.
 
  Interestingly, convergence proves harder to obtain for this case,
  in which the air and water travel in the same direction, than in
  case 895, in which the flow directions were opposed. So heavier
  under-relaxation, and a larger number of sweeps, are employed.
 
  ENDDIS
PATCH(AIRIN,NORTH,1,1,NY,NY,1,1,1,LSTEP)
LSWEEP=100;SELREF=T;RESFAC=1.E-6
RELAX(GAS,LINRLX,0.1);RELAX(LIQ,LINRLX,0.1)
TSTSWP=LSWEEP-1;iymon=ny-1