TALK=T;RUN( 1, 1) ** LOAD(x307) from the x Input Library GROUP 1. Run title and other preliminaries TEXT(REALISABLE KE_2D FLOW PAST A SQUARE RIB: T307 TITLE DISPLAY The case considered is 2D, steady, incompressible, turbulent flow past a surface-mounted square rib in a channel. This case has been studied experimentally by D.Crabb et al, Proc. 4th Brazilian Congress on Mech. Engng., Florianopolis, Brazil, p415,(1997). The height H of the rib is 8.5% of that of the channel. The flow Reynolds number based on channel bulk velocity and rib height H is 300,000. The inlet plane is located 6H upstream of the rib, and the outlet plane 20H downstream of the rib. A fixed-pressure boundary condition is applied at the outlet, and uniform flow profiles are specified at the inlet. The case is set up to run one of six versions of the k-e model with scalable wall functions, and four different versions of the k-w model. For this case, the main parameter characterising separation is the length of the separation zone behind the rib. The experimental and computed results are: KE MMK KL CK RKE RNG KW KWR MKW SST EXPT Lr/H = 8.3 11.4 11.2 15.1 12.9 13.7 8.0 11.7 8.3 12.3 12.3 where the separation length Lr is measured from the front of the rib. These results are not grid independent, and the mesh is not fine enough to resolve the separation regions around the rib. The standard k-e & k-w models seriously underpredict the length of the separation behind the rib, whilst the k-w-SST, the Wilcox 2008 k-w and realisable k-e models give closest agreement with the data. ENDDIS The AUTOPLOT sequence below provides a plot of the axial velocity W1 along the bottom surface of the solution domain versus normalised axial distance. The axial coordinate 0.0 corresponds to the rear surface of the rib. The reattachment point behind the cube corresponds the axial location where W1 changes from negative to positive. AUTOPLOT USE AUTOPLOT FILE PHIDA 3 D 1 W1 Y 1 PLOT LEVEL Y 0 SHIFT X -7 1 REDR SCALE X 0 15 msg Press e to END ENDUSE CHAR(CTURB) REAL(HRIB,CLUP,CLDOWN,HCHAN,WCHAN,RECHAN) REAL(RERIB,UIN,TKEIN,EPSIN,MIXL,FRIC,OMIN) INTEGER(NYC,NZC,NZUP,NZDOWN,NYUP) ** Calculation of domain specifications HRIB=1.0;UIN=1.0 HCHAN=11.75*HRIB CLUP=6.*HRIB;CLDOWN=20.*HRIB RERIB=3.E5 RECHAN=RERIB*HCHAN/HRIB ** NB: Channel hydraulic diameter=2.*hchan RECHAN=2.*RECHAN ** Estimate inlet conditions assuming fully-developed duct flow at the inlet FRIC=1./(1.82*LOG10(RECHAN)-1.64)**2 FRIC TKEIN=0.25*UIN*UIN*FRIC MIXL=0.045*HCHAN;EPSIN=0.1643*TKEIN**1.5/MIXL NYC=28;NYUP=62 NZUP=34;NZC=12;NZDOWN=64 GROUP 3. X-direction grid specification GROUP 4. Y-direction grid specification NREGY=2 IREGY=1;GRDPWR(Y,NYC,HRIB,1.0) IREGY=2;GRDPWR(Y,-NYUP,-(HCHAN-HRIB),1.08) GROUP 5. Z-direction grid specification NREGZ=3 IREGZ=1;GRDPWR(Z,NZUP,-CLUP,-1.05) IREGZ=2;GRDPWR(Z,NZC,HRIB,1.0) IREGZ=3;GRDPWR(Z,NZDOWN,-CLDOWN,1.04) GROUP 7. Variables stored, solved & named SOLVE(P1,V1,W1);SOLUTN(P1,Y,Y,Y,N,N,N);STORE(ENUT) SOLUTN(V1,Y,Y,Y,P,P,N);SOLUTN(W1,Y,Y,Y,P,P,N) MESG( Enter the required turbulence model: MESG( KE - Standard k-e model MESG( MMK - MMK k-e model MESG( KL - KL k-e model MESG( CK - Chen-Kim k-e model MESG( RKE - Realisable k-e model (default) MESG( RNG - RNG k-e model MESG( KW - Wilcox 1988 k-w model MESG( KWR - Wilcox 2008 k-w model MESG( KWM - Menter 1992 k-w model MESG( KWS - k-w SST model MESG( READVDU(CTURB,CHAR,RKE) CASE :CTURB: OF WHEN KE,2 + TEXT(K-E 2D SQUARE RIB FLOW :T307 + MESG(Standard k-e model + TURMOD(KEMODL) WHEN MMK,3 + TEXT(MMK K-E SQUARE RIB FLOW :T307 + MESG(MMK k-e model + TURMOD(KEMMK) WHEN KL,2 + TEXT(KL K-E SQUARE RIB FLOW :T307 + MESG(KL k-e model + TURMOD(KEKL) WHEN CK,2 + TEXT(Chen-Kim K-E SQUARE RIB FLOW :T307 + MESG(Chen Kim k-e model + TURMOD(KECHEN) WHEN RNG,3 + TEXT(RNG K-E SQUARE RIB FLOW :T307 + MESG(RNG k-e model + TURMOD(KERNG) WHEN RKE,3 + TEXT(RK K-E SQUARE RIB FLOW :T307 + MESG(RK k-e model + TURMOD(KEREAL);STORE(C1E) WHEN KW,2 + TEXT(Wilcox 1988 k-w SQUARE RIB FLOW :T307 + MESG(Wilcox 1988 k-w model + TURMOD(KWMODL) + OMIN=EPSIN/(0.09*TKEIN) WHEN KWR,3 + TEXT(Wilcox 2008 k-w SQUARE RIB FLOW :T307 + MESG(Wilcox 2008 k-w model + TURMOD(KWMODLR) + OMIN=EPSIN/(0.09*TKEIN) + FIINIT(FBP)=1.0;STORE(CDWS) WHEN KWM,3 TEXT(Menter k-w SQUARE RIB FLOW :T307 + MESG(Menter 1992 k-w model + TURMOD(KWMENTER);;FIINIT(BF1)=1.0 + OMIN=EPSIN/(0.09*TKEIN);STORE(CDWS) WHEN KWS,3 TEXT(SST k-w SQUARE RIB FLOW :T307 + MESG(Menter 1992 k-w SST model + TURMOD(KWSST);FIINIT(BF1)=1.0;FIINIT(BF2)=1.0 + STORE(CDWS);OMIN=EPSIN/(0.09*TKEIN) ENDCASE BOOLEAN(KWMOD) KWMOD=IENUTA.EQ.10.OR.IENUTA.EQ.15.OR.IENUTA.EQ.17.OR.IENUTA.EQ.19 IF(KWMOD) THEN + SOLUTN(KE,Y,Y,Y,P,P,P);SOLUTN(OMEG,Y,Y,Y,P,P,P) ELSE + SOLUTN(KE,Y,Y,Y,P,P,P);SOLUTN(EP,Y,Y,Y,P,P,P) ENDIF STORE(YPLS) SCALWF=T ! Scalable wall functions GROUP 8. Terms (in differential equations) & devices GROUP 9. Properties of the medium (or media) RHO1=1.0;ENUL=UIN*HRIB/RERIB GROUP 11. Initialization of variable or porosity fields FIINIT(W1)=UIN;FIINIT(P1)=1.3E-4 FIINIT(KE)=TKEIN;FIINIT(EP)=EPSIN;FIINIT(V1)=0.001*UIN IF(KWMOD) THEN + FIINIT(OMEG)=OMIN ENDIF ** Initialization of variables in blocked region STORE(PRPS) PATCH(RIB,INIVAL,#1,#1,#1,#1,#2,#2,1,1) INIT(RIB,PRPS,0.,198) EGWF=T GROUP 13. Boundary conditions and special sources INLET(INLET,LOW,#1,#NREGX,#1,#NREGY,#1,#1,1,1) VALUE(INLET,P1,UIN);VALUE(INLET,W1,UIN) VALUE(INLET,KE,TKEIN);VALUE(INLET,EP,EPSIN) IF(KWMOD) THEN +VALUE(INLET,OMEG,OMIN) ENDIF PATCH(OUTL,HIGH,#1,#NREGX,#1,#NREGY,#NREGZ,#NREGZ,1,1) COVAL(OUTL,P1,1.0E3,0.0) COVAL(OUTL,W1,ONLYMS,0.0);COVAL(OUTL,V1,ONLYMS,0.0) COVAL(OUTL,KE,ONLYMS,0.0);COVAL(OUTL,EP,ONLYMS,0.0) WALL(WALLN,NORTH,#1,#NREGX,#NREGY,#NREGY,#1,#NREGZ,1,1) WALL(WALLS,SOUTH,#1,#NREGX,#1,#1,#1,#NREGZ,1,1) IF(KWMOD) THEN + COVAL(WALLN,OMEG,GRND2,GRND2) + COVAL(WALLS,OMEG,GRND2,GRND2) ENDIF GROUP 15. Termination of sweeps LSWEEP=1800 GROUP 16. Termination of iterations SELREF=T LITER(P1)=50;LITER(KE)=5;LITER(EP)=5 GROUP 17. Under-relaxation devices REAL(DTF);DTF=ZWLAST/UIN/NZ/2 RELAX(W1,FALSDT,DTF);RELAX(V1,FALSDT,DTF) IF(KWMOD) THEN + LITER(OMEG)=5 + RELAX(KE,FALSDT,DTF);RELAX(OMEG,FALSDT,DTF) ELSE + KELIN=3 + RELAX(KE,LINRLX,0.3);RELAX(EP,LINRLX,0.3) ENDIF IYMON=NYC-4;IXMON=1;IZMON=NZUP+NZC+10;NPRMON=100 IYMON=30;IXMON=67 GROUP 23. Field print-out and plot control ITABL=3;NPLT=25;IPLTL=LSWEEP;NZPRIN=4;NYPRIN=4 TSTSWP=-1 SPEDAT(SET,GXMONI,PLOTALL,L,T) SPEDAT(SET,OUTPUT,NOFIELD,L,T) ** Revised Wilcox moddel IF(IENUTA.EQ.15) THEN + SCALWF=F ! deactivate scalable wall functions + RELAX(FBP,LINRLX,0.05) + OUTPUT(FBP,Y,N,Y,N,Y,Y);OUTPUT(XWP,Y,N,Y,N,Y,Y) + OUTPUT(CDWS,Y,N,Y,N,Y,Y) + LSWEEP=3000 ENDIF ** k-w-SST model IF(IENUTA.EQ.19) THEN + LSWEEP=2000 ENDIF OUTPUT(ENUT,Y,N,Y,N,Y,Y) DISTIL=T CASE :CTURB: OF WHEN KE,2 +EX(EPKE)=1.136E-01;EX(PRPS)=9.661E-01 +EX(P1 )=1.279E-01;EX(V1 )=6.438E-02 +EX(W1 )=8.001E-01;EX(KE )=1.590E-02 +EX(EP )=3.310E-03;EX(YPLS)=4.941E+00 +EX(ENUT)=1.601E-02 WHEN MMK,3 +EX(P1 )=1.464E-01;EX(V1 )=6.987E-02 +EX(W1 )=7.850E-01;EX(KE )=1.200E-02 +EX(EP )=2.174E-03;EX(EPKE)=1.096E-01 +EX(PRPS)=9.661E-01;EX(YPLS)=4.969E+00 +EX(DWDY)=2.871E-01;EX(DVDZ)=4.714E-02 +EX(FOMG)=5.301E-01;EX(ENUT)=9.002E-03 WHEN KL,2 +EX(P1 )=1.454E-01;EX(V1 )=6.957E-02 +EX(W1 )=7.856E-01;EX(KE )=1.200E-02 +EX(EP )=2.182E-03;EX(EPKE)=1.111E-01 +EX(PRPS)=9.661E-01;EX(YPLS)=4.943E+00 +EX(DWDY)=2.858E-01;EX(DVDZ)=4.671E-02 +EX(FOMG)=5.751E-01;EX(ENUT)=1.397E-02 WHEN CK,2 +EX(P1 )=1.590E-01;EX(V1 )=7.342E-02 +EX(W1 )=7.788E-01;EX(KE )=8.821E-02 +EX(EP )=1.647E-03;EX(EPKE)=1.196E-01 +EX(PRPS)=9.661E-01;EX(YPLS)=4.981E+00 +EX(ENUT)=1.129E-02 WHEN RKE,3 +EX(P1 )=1.512E-01;EX(V1 )=7.132E-02 +EX(W1 )=7.815E-01;EX(KE )=1.017E-02 +EX(EP )=1.776E-03;EX(PRPS)=9.661E-01 +EX(YPLS)=4.931E+00;EX(C1E )=4.664E-01 +EX(DWDZ)=7.146E-02;EX(DWDY)=2.955E-01 +EX(DVDZ)=4.759E-02;EX(DVDY)=7.292E-02 +EX(EPKE)=1.117E-01;EX(CMU )=1.096E-01 +EX(ENUT)=1.484E-02 WHEN RNG,3 +EX(P1 )=1.561E-01;EX(V1 )=7.308E-02 +EX(W1 )=7.816E-01;EX(KE )=9.889E-02 +EX(EP )=1.682E-03;EX(EPKE)=1.181E-01 +EX(PRPS)=9.661E-01;EX(YPLS)=4.934E+00 +EX(ENUT)=1.149E-02 WHEN KW,2 +EX(P1 )=1.271E-01;EX(V1 )=6.348E-02 +EX(W1 )=8.010E-01;EX(KE )=1.747E-02 +EX(EP )=3.564E-03;EX(EPKE)=9.661E-11 +EX(PRPS)=9.661E-01;EX(YPLS)=5.138E+00 +EX(OMEG)=1.182E+00;EX(ENUT)=1.770E-02 WHEN KWR,3 +EX(P1 )=1.450E-01;EX(V1 )=6.907E-02 +EX(W1 )=7.812E-01;EX(KE )=1.266E-02 +EX(EP )=2.346E-03; +EX(PRPS)=9.661E-01;EX(YPLS)=5.091E+00 +EX(CDWS)=1.075E-01;EX(DWDZ)=6.958E-02 +EX(DWDY)=2.747E-01;EX(DVDZ)=4.752E-02 +EX(DVDY)=7.104E-02;EX(GEN1)=4.946E+00 +EX(FBP )=9.607E-01;EX(XWP )=1.437E+00 +EX(OMEG)=1.109E+00;EX(ENUT)=1.331E-02 WHEN KWM,3 +EX(P1 )=1.279E-01;EX(V1 )=6.430E-02 +EX(W1 )=8.090E-01;EX(KE )=1.633E-02 +EX(EP )=3.330E-03; +EX(PRPS)=9.661E-01;EX(YPLS)=4.999E+00 +EX(CDWS)=2.394E-01;EX(LTLS)=6.637E+00 +EX(WDIS)=1.560E+00;EX(BF1 )=7.176E-01 +EX(OMEG)=1.219E+00;EX(ENUT)=1.649E-02 WHEN KWS,3 +EX(P1 )=1.467E-01;EX(V1 )=7.121E-02 +EX(W1 )=7.809E-01;EX(KE )=1.151E-02 +EX(EP )=1.893E-03; +EX(PRPS)=9.661E-01;EX(YPLS)=4.845E+00 +EX(CDWS)=6.563E-02;EX(LTLS)=6.637E+00 +EX(WDIS)=1.560E+00;EX(GEN1)=5.684E+00 +EX(BF2 )=9.350E-01;EX(BF1 )=7.172E-01 +EX(OMEG)=1.183E+00;EX(ENUT)=1.255E-02 ENDCASE STOP