L(450) TEXT(Rigid-Surface Flow, 3D Compress TITLE DISPLAY Shallow water theory is invoked in this case to emulate the surface waves. This theory recognizes the analogy with the isentropic flow of an ideal gas with a ratio of principal specific heats of 2. RHO1=COMPRESS activates the isentropic gas law formula in GREX3. ENDDIS CON=9.81*0.025;VARMIN(P1)=0.001-CON RHO1=COMPRESS;RHO1A=CON**-0.5;PRESS0=CON;RHO1B=0.5;RHO1C=0.0