TITLE 'test' VARIABLES vx(1) Xm = MOVE(x) DEFINITIONS visc=1000 R0 = 1 ! boundary velocity on all sides Bvx = (300 - 350*(y+7)/(3+7))*URAMP(t,t-0.01) EQUATIONS vx: visc*div( grad( vx))=0 Xm: dt(Xm) = vx ngrid=30 regrid=off BOUNDARIES REGION 1 mesh_spacing=1 START(-5,-7) value( vx)=Bvx LINE TO (6,-7) TO (6,3) TO (-5,3) TO CLOSE REGION 2 mesh_spacing=1 visc=3000 START 'ring' (R0,-2) !tautology: VELOCITY(Xm) = vx ARC(CENTER=0,-2) ANGLE=360 TO CLOSE TIME 0 TO 0.05 by 1e-5 monitors for cycle=1 contour(vx) painted grid(x,y) PLOTS FOR T = 0, 0.001 BY 0.001 TO 0.05 contour(vx) grid(x,y) END