PHOTON USE p p2 10 1 view x norm gr ou x 1 msg Velocity vectors - time=1 sec vec x 1 sh msg msg Pressto continue pause vec off;red msg Pressure distribution - time=1 sec con p1 x 1 fi;.01 msg msg Press to continue pause con off;red msg Temperature distribution - Prandtl number 0.7: con h1 x 1 fi;.001 msg Press to continue pause con off;red msg Temperature distribution - Prandtl number 1.0: con a x 1 fi;.001 msg msg Press to continue pause con off;red msg Temperature distribution - Prandtl number 0.1: con b x 1 fi;.001 msg msg Press to see results after increase in flow rate pause p p4 10 1 view x norm gr ou x 1 msg Velocity vectors - time=3 sec vec x 1 sh msg msg Press to continue pause vec off;red msg Pressure distribution - time=3 sec con p1 x 1 fi;.01 msg msg Press to continue pause con off;red msg Temperature distribution - Prandtl number 0.7: con h1 x 1 fi;.001 msg Press to continue pause con off;red msg Temperature distribution - Prandtl number 1.0: con a x 1 fi;.001 msg msg Press to continue pause con off;red msg Temperature distribution - Prandtl number 0.1: con b x 1 fi;.001 msg msg Press e to END enduse GROUP 1. Run title and other preliminaries TEXT(Laminar Flow In Pipe-Transient TITLE mesg(PC486/50 time last reported as appx. 1.5 min DISPLAY This case examines the transient flow in a pipe resulting from an abrupt change in inlet conditions. The uniform inflow is imposed at the inlet, at the start of the calculation. The pipe-wall temperature differs from the initial temperature of the flow. Three extra variables are treated as temperatures with different Prandtl numbers. The development of the transient flow can be studied through changing parameters such as geometry, flow properties and flow rate at the inlet. hot pipe wall //////////////////////////// inlet ----------------------------- ----> uniform inflow exit ----> _________________________axis____________ For a grid-independent solution, smaller grid size is needed. ENDDIS GROUP 2. Transience; time-step specification ** Activate unsteady term in the solved equations STEADY=F IREGT=1; GRDPWR(T,5,0.5,1.0) GROUP 3. X-direction grid specification CARTES=F * Write objects RSET(D,PIPE,1.,0.01,0.5,1,0) RSET(B,PIPEW,0,0.01,0,1.,0,0.5,11,0) GROUP 4. Y-direction grid specification IREGY=1; GRDPWR(Y,10,0.01,1.0) GROUP 5. Z-direction grid specification IREGZ=1; GRDPWR(Z,10,0.5,1.0) GROUP 6. Body-fitted coordinates or grid distortion GROUP 7. Variables stored, solved & named ** Solve for three extra variables, A, B AND C, treated as temperatures with different Prandtl numbers. SOLVE(P1,V1,W1,H1,C1,C2,C3) NAME(C1)=A; NAME(C2)=B; NAME(C3)=C GROUP 8. Terms (in differential equations) & devices GROUP 9. Properties of the medium (or media) ENUL=1.E-5;PRNDTL(H1)=0.7 PRNDTL(A)=1.0;PRNDTL(B)=0.1;PRNDTL(C)=10.0 GROUP 13. Boundary conditions and special sources 1. Wall at north boundary WALL (PIPEW,NORTH,#1,#1,#NREGY,#NREGY,#1,#NREGZ,#1,#NREGT) COVAL(PIPEW,W1,1.0,0.0);COVAL(PIPEW,H1,1./PRNDTL(H1),1.0) COVAL(PIPEW,A,1.0,1.0);COVAL(PIPEW,B,10.0,1.0) COVAL(PIPEW,C,0.1,1.0) 2. Inlet-- uniform flow INLET(UNIFORM,LOW,#1,#1,#1,#NREGY,#1,#1,#1,#NREGT) VALUE(UNIFORM,P1,0.1);VALUE(UNIFORM,W1,0.1) VALUE(UNIFORM,V1,0.0);VALUE(UNIFORM,H1,0.0) VALUE(UNIFORM,A,0.0);VALUE(UNIFORM,B,0.0) VALUE(UNIFORM,C,0.0) 2. Outlet-- fixed pressure PATCH(OUTLET,HIGH,#1,#1,#1,#NREGY,#NREGZ,#NREGZ,#1,#NREGT) COVAL(OUTLET,P1,FIXVAL,0.0) COVAL(OUTLET,V1,ONLYMS,0.0);COVAL(OUTLET,W1,ONLYMS,0.0) GROUP 15. Termination of sweeps LSWEEP=20 RESREF(P1)=1.E-6;RESREF(V1)=1.E-6 RESREF(H1)=1.E-6;RESREF(W1)=1.E-6 RESREF(A)=1.E-6;RESREF(B)=1.E-6;RESREF(C)=1.E-6 SPEDAT(SET,GXMONI,TRANSIENT,L,F) GROUP 22. Spot-value print-out NPRMON=LSWEEP;IYMON=5 GROUP 22. Spot-value print-out IYMON=NY/2;IZMON=NZ/2;IPLTL=30 GROUP 23. Field print-out and plot control NTPRIN=1 NZPRIN=2 PATCH(TIMPLOT1,PROFIL,1,1,1,NY,NZ-1,NZ-1,1,LSTEP) PLOT(TIMPLOT1,W1,0.0,0.2);PLOT(TIMPLOT1,A,0.0,1.0) PLOT(TIMPLOT1,B,0.0,1.0);PLOT(TIMPLOT1,C,0.0,1.0) PATCH(TIMPLOT2,CONTUR,1,1,1,NY,1,NZ,1,LSTEP) PLOT(TIMPLOT2,W1,0.0,10);PLOT(TIMPLOT2,H1,0.0,10) PLOT(TIMPLOT2,A,0.0,10);PLOT(TIMPLOT2,B,0.0,10.0) PLOT(TIMPLOT2,C,0.0,10) ***actdem*** xulast=.01 2. Inlet-- uniform flow Re=100 INLET(UNIFORM,LOW,#1,#1,#1,#NREGY,#1,#1,1,2) VALUE(UNIFORM,P1,0.1);VALUE(UNIFORM,W1,0.1) VALUE(UNIFORM,V1,0.0);VALUE(UNIFORM,H1,0.0) VALUE(UNIFORM,A,0.0);VALUE(UNIFORM,B,0.0) VALUE(UNIFORM,C,0.0) 3. Inlet-- uniform flow Re=1000 INLET(re1000,LOW,#1,#1,#1,#NREGY,#1,#1,3,lstep) VALUE(re1000,P1,1.0);VALUE(re1000,W1,1.0) VALUE(re1000,V1,0.0);VALUE(re1000,H1,0.0) VALUE(re1000,A,0.0);VALUE(re1000,B,0.0) VALUE(re1000,C,0.0) idispa=1; csg1=p selref=t; resfac=1.e-2 tstswp=-1