#$921
text(Free Conv.; Steel Block In Water 
#cls
title
  DISPLAY
  
  The geometry is as for case 921, but the north wall no longer
  moves. Instead, the motion is induced by allowing for the
  effect of buoyancy, by way of the Boussinesq approximation.
  
  The PHOTON USE macro of case 921 can be activated by issuing the
  command 'use Q1EAR'; but not 'use Q1'. The reason is that the
  date of case 921 have been brought in by way of the compact
  #$921 command above.
   
  ENDDIS
#pause  
moving=skip   ! to de-activate the moving wall
 
#gravity
gravdir=2; Tref = WALLTEMP
#bouss
libref=922