GROUP 1. Run title and other preliminaries TEXT(0D Piston-In-Cylinder Study TITLE DISPLAY One computational cell is used in this study of the variation of pressure as a piston moves from bottom dead-centre, through top dead-centre, and back. Interesting variations include: alteration of the engine speed; and changes to the ratio of connecting-rod length to crank radius. ENDDIS Special data ============== OMEGA The rotation rate rad/sec GAMA The isentropic index REAL(GAMA,PI,OMEGA) GAMA=1.4; PI=3.14159; OMEGA=12.0 GROUP 2. Transience; time-step specification STEADY=F; GRDPWR(T,20,2.0*PI/OMEGA,1.0) GROUP 5. Z-direction grid specification GRDPWR(Z,1,0.1,1.0) GROUP 7. Variables stored, solved & named SOLVE(P1) GROUP 9. Properties of the medium (or media) *** Set density, rho = RHO1A * (PRESS0 + P1)**RHO1B (See GREX3, Group 9, Sec.1, and GXRHO) RHO1=COMPRESS; RHO1A=1.484E-4; RHO1B=1./GAMA; PRESS0=1.E5 *** Set source term (1./rho)*(d(rho)/dp) (See GREX3, Group 9, Sec.2, and GXDRDP) DRH1DP=COMPRESS GROUP 11. Initialization of variable or porosity fields FIINIT(P1)=0.0 GROUP 15. Termination of sweeps LSWEEP=5 GROUP 19. Data communicated by satellite to GROUND *** To activate moving grid by setting W1AD=ZMOVE (See GREX3, Group 19,Sec.1, and GXPIST) AZW1--- The rotation rate BZW1--- The crank radius CZW1--- The ratio of the connecting-rod length to the crank radius IZW1--- The iz location of the last slab in part one of an n-part moving grid W1AD=ZMOVE; AZW1=OMEGA; BZW1=0.025; CZW1=10.0; IZW1=1 SPEDAT(SET,GXMONI,TRANSIENT,L,F) GROUP 22. Spot-value print-out TSTSWP=LSWEEP GROUP 23. Field print-out and plot control *** Plot pressure variation with time NPLT=1 PATCH(TIMEPLOT,PROFIL,1,1,1,1,1,1,1,LSTEP) PLOT (TIMEPLOT,P1,0.0,0.0)