TALK=T;RUN( 1, 1) ************************************************************ Q1 created by VDI menu, Version 2020, Date 13/01/21 CPVNAM=VDI; SPPNAM=Core ************************************************************ Echo DISPLAY / USE settings PHOTON USE AUTOPLOT file phida 3 cl msg CASSON-PAPANASTASIOU PIPE FLOW msg Reynolds number = 2.75 msg Pressure(P1) profile msg Blue line --- PHOENICS solution msg crosses --- analytical solution da 1 p1 y 1;da 1 pa y 1 col3 1;blb4 2 redr pause msg pressto continue clear msg Velocity (W1) profile da 1 w1 z 35;da 1 wa z 35 col3 1;blb4 2 pause msg press to end pause end END_USE ************************************************************ IRUNN = 1 ;LIBREF = 112 ************************************************************ Group 1. Run Title TEXT(112 2d pipe flow - Casson-Papan. fluid ) ************************************************************ Echo save-block settings for Group 1 save1begin This case concerns the steady laminar flow of a Casson- Panastasiou non-Newtonian fluid in a circular pipe. The apparent viscosity of such a fluid is given by: emu = ( Fp*(tau0/G)^1/2 + K^1/2)^2 where K is the consistency index, tau0 is the yield stress, and Fp is the Pananastasiou regularisation function. The shear stress tau = emu*G where G is the mean strain rate. Casson fluids have applications in metallurgy, drilling operations,food processing and most importantly in describing the flow of blood. The bulk inlet velocity is 1m/s and the fluid density is 1 kg/m^3. The pipe diameter and length are 0.1m and 1m, respectively; and the rheology parameters are set to: K=0.02 Pa.s and tau0 = 2 N/m^2. These conditions correspond to a flow Reynolds number based on K of 10, and a Casson number C of 20, where C=tau0*D/(U*K). The task is to predict the pressure drop and fully-developed axial-velocity profile for a given Reynolds number, and then compare the results with the analytical solutions. The inform facility is used to compute the analytical profiles of pressure and velocity, and the solutions are stored in PA and WA, respectively. save1end ************************************************************ Group 2. Transience STEADY = T ************************************************************ Groups 3, 4, 5 Grid Information * Overall number of cells, RSET(M,NX,NY,NZ,tolerance) RSET(M,1,20,40,8.333333E-05) * Cylindrical-polar grid CARTES=F ************************************************************ Group 6. Body-Fitted coordinates ************************************************************ Group 7. Variables: STOREd,SOLVEd,NAMEd * Non-default variable names NAME(140)=GR ;NAME(141)=TAUR NAME(142)=WDIS ;NAME(143)=SRM1 NAME(144)=STRS ;NAME(146)=BTAU NAME(147)=PA ;NAME(148)=WA NAME(149)=GEN1 ;NAME(150)=VISL * Solved variables list SOLVE(P1,V1,W1) * Stored variables list STORE(VISL,GEN1,WA,PA,BTAU,STRS,SRM1,WDIS) STORE(TAUR,GR) * Additional solver options SOLUTN(P1,Y,Y,Y,N,N,Y) SOLUTN(V1,Y,Y,Y,N,N,Y) SOLUTN(W1,Y,Y,Y,N,N,Y) ************************************************************ Echo save-block settings for Group 7 save7begin STORE(SRM1) ! = (GEN1)^0.5 save7end ************************************************************ Group 8. Terms & Devices ADDDIF = T NEWENL = T ************************************************************ Group 9. Properties RHO1 =1. ENUL = GRND4 ENULA =0.02 ;ENULB =2. ;ENULC =0. CP1 =1. DISWAL ENUT =1.0E-10 ************************************************************ Echo save-block settings for Group 9 save9begin REAL(RIN,DIN,WIN,DPDZ,CASSN,FX,FXP,GRP) REAL(TAUW,TAUP,CONSI,TAU0,ACON,BCON,CCON,REY) RIN=0.1 ! Pipe radius DIN=2.*RIN ! Pipe diameter WIN=1.0 ! Bulk inlet velocity REY=10. ! Reynolds number ENUL=GRND4;IENULA=-8 ! Casson--Papanastasiou fluid CONSI=ENULA ; TAU0=ENULB ETA = (SQRT(TAU0/GAMDOT)+SQRT(CONSI) )**2 ENULA=DIN*WIN/REY ! Consistency index CASSN=20.0 ! Casson number ENULB=CASSN*WIN*ENULA/DIN ! Yield stress ENULD=1.E10 ! Papanastasiou time constant REY;CASSN;ENULA;ENULB ** Analytical pressure solution CONSI= ENULA ; TAU0 = ENULB DPDZ=8.*CONSI*WIN/RIN**2 ! "Newtonian" pressure drop TAUW=0.5*RIN*DPDZ ! Force balance in flow direction DPDZ;TAUW iterate for analytical wall shear stress ACON=4.*SQRT(TAU0)/7. ;BCON=(TAU0**4)/84. ; CCON=TAU0/3. TAUP=100.0 DO II=1,20 IF(ABS(TAUP).GT.1.E-3) THEN FX =0.25*TAUW-ACON*(TAUW)**0.5-BCON/TAUW**3+CCON-WIN*CONSI/RIN FXP=0.25-(0.5*ACON/TAUW**0.5)+3.*BCON/TAUW**4 TAUP=-FX/FXP TAUW=TAUW+TAUP II;TAUW;TAUP ENDIF ENDDO DPDZ=2.*TAUW/RIN TAUW;DPDZ (make1 zgnz is 0) (store1 zgnz is zg with IF(IZ.EQ.NZ)) (print zgnz is zgnz) (stored of PA is -DPDZ*(ZG-ZGNZ)) ** Analytical axial velocity profile ACON=0.5*RIN*TAUW/CONSI BCON=(8./3.)*(TAU0/TAUW)**0.5 CCON=2.*TAU0/TAUW (stored of GR is YG/:RIN:) GRP=TAU0/TAUW ! Critical radius GRP (stored of GR is :GRP: with IF(GR.LE.:GRP:)) (stored of WA is ACON*((1.-GR^2)-BCON*(1.-GR^1.5)+CCON*(1.-GR))) ** Stress-ratio output (stored of TAUR is BTAU/:TAU0:) save9end ************************************************************ Group 10.Inter-Phase Transfer Processes ************************************************************ Group 11.Initialise Var/Porosity Fields FIINIT(W1)=1. ;FIINIT(WDIS)=0.1 FIINIT(BTAU)=1.001E-10 ;FIINIT(GEN1)=1.001E-10 FIINIT(VISL)=1.001E-10 No PATCHes used for this Group INIADD = F ************************************************************ Group 12. Convection and diffusion adjustments No PATCHes used for this Group ************************************************************ Group 13. Boundary & Special Sources No PATCHes used for this Group EGWF = T ************************************************************ Group 14. Downstream Pressure For PARAB ************************************************************ Group 15. Terminate Sweeps LSWEEP = 2000 RESREF(P1)=5.0E-16 ;RESREF(V1)=5.0E-16 RESREF(W1)=5.0E-16 RESFAC =1.0E-04 ************************************************************ Group 16. Terminate Iterations ************************************************************ Group 17. Relaxation RELAX(P1 ,LINRLX,1. ) RELAX(V1 ,FALSDT,0.05 ) RELAX(LTLS,LINRLX,1. ) ************************************************************ Group 18. Limits ************************************************************ Group 19. EARTH Calls To GROUND Station GENK = T PARSOL = F ISG62 = 1 SPEDAT(SET,OUTPUT,NOFIELD,L,T) SPEDAT(SET,GXMONI,PLOTALL,L,T) ************************************************************ Group 20. Preliminary Printout DISTIL = T ;NULLPR = F NDST = 0 DSTTOL =1.0E-02 EX(P1)=62.150002 ;EX(V1)=0.01334 EX(W1)=1.101 ;EX(GR)=0.6035 EX(TAUR)=1.888 ;EX(WDIS)=0.03452 EX(SRM1)=18.540001 ;EX(STRS)=0.3166 EX(LTLS)=1.498E-03 ;EX(BTAU)=3.776 EX(PA)=60.740002 ;EX(WA)=1.108 EX(GEN1)=712.400024 ;EX(VISL)=458.899994 ************************************************************ Group 21. Print-out of Variables OUTPUT(BTAU,Y,N,Y,N,Y,Y) OUTPUT(PA ,Y,N,Y,N,Y,Y) OUTPUT(WA ,Y,N,Y,N,Y,Y) OUTPUT(VISL,Y,N,Y,N,Y,Y) ************************************************************ Group 22. Monitor Print-Out IXMON = 1 ;IYMON = 12 ;IZMON = 32 NPRMON = 100000 NPRMNT = 1 TSTSWP = -1 ************************************************************ Group 23.Field Print-Out & Plot Control NPRINT = 100000 NYPRIN = 1 NZPRIN = 1 YZPR = T ISWPRF = 1 ;ISWPRL = 100000 No PATCHes used for this Group ************************************************************ Group 24. Dumps For Restarts ************************************************************ Echo save-block settings for Group 24 save24begin DISTIL=T EX(P1 )=6.215E+01;EX(V1 )=1.334E-02 EX(W1 )=1.101E+00;EX(GR )=6.035E-01 EX(TAUR)=1.888E+00;EX(STRS)=3.166E-01 EX(SRM1)=1.854E+01;EX(BTAU)=3.776E+00 EX(PA )=6.074E+01;EX(WA )=1.108E+00 EX(GEN1)=7.124E+02;EX(VISL)=4.589E+02 save24end GVIEW(P,-1.,0.,0.) GVIEW(UP,0.,1.,0.) GVIEW(VDIS,0.527151) GVIEW(CENTRE,4.991671E-03,0.05,0.5) > DOM, SIZE, 1.000000E-01, 1.000000E-01, 1.000000E+00 > DOM, MONIT, 5.000000E-02, 6.675906E-02, 8.208498E-01 > DOM, SCALE, 1.000000E+00, 1.000000E+00, 1.000000E+00 > DOM, INCREMENT, 1.000000E-02, 1.000000E-02, 1.000000E-02 > GRID, RSET_X_1, 1, 1.000000E+00 > GRID, RSET_Y_1, 20,-1.040000E+00,G > GRID, RSET_Z_1, -40, 1.200000E+00 > DOM, T_AMBIENT, 0.000000E+00 > OBJ, NAME, INLET > OBJ, POSITION, 0.000000E+00, 0.000000E+00, 0.000000E+00 > OBJ, SIZE, 1.000000E-01, TO_END, 0.000000E+00 > OBJ, DOMCLIP, NO > OBJ, GEOMETRY, poldef > OBJ, TYPE, INLET > OBJ, PRESSURE, P_AMBIENT > OBJ, VELOCITY, 0. ,0. ,1. > OBJ, NAME, OUTL > OBJ, POSITION, 0.000000E+00, 0.000000E+00, AT_END > OBJ, SIZE, 1.000000E-01, TO_END, 0.000000E+00 > OBJ, DOMCLIP, NO > OBJ, GEOMETRY, poldef > OBJ, TYPE, OUTLET > OBJ, PRESSURE, 0. > OBJ, COEFFICIENT, 100. > OBJ, VELOCITY, 0. ,0. , SAME > OBJ, NAME, WALL > OBJ, POSITION, 0.000000E+00, AT_END, 0.000000E+00 > OBJ, SIZE, 1.000000E-01, 0.000000E+00, TO_END > OBJ, DOMCLIP, NO > OBJ, GEOMETRY, poldef > OBJ, TYPE, PLATE STOP