GROUP 1. Run title and other preliminaries TEXT(LAM-BRE KE_1D PLANE COUETTE FLOW :T205 TITLE mesg(PC486/50 time last reported as appx. 40.sec DISPLAY The problem considered is plane turbulent couette flow in a channel at Re=1.E5, as described in detail for library case T100. The turbulence is simulated by use of the Lam-Bremhorst low-Re k-e model. The calculation integrates down to the wall and the solution is performed by use of the single-slab solver. A non- uniform grid is employed so as to concentrate cells very close to the walls. The calculation may also be performed with the Chen- Kim low-Re k-e model and the Wilcox low-Re k-omega model. ENDDIS The Lam-Bremhorst and Chen-Kim models predict skin-friction coefficients Cf of 3.78E-3 and 3.50e-3 respectively, which are in reasonable agreement with the experimental value of 3.07E-3 suggested by the data of El Telbany and Reynolds [1982]. The k-omega model produces much closer agreement, yielding Cf=2.931e-3, where Cf=2.*tauw/(rho*Uav**2) and Uav is the average velocity. The following AUTOPLOT use file produces three plots; the first is the axial velocity profile; the second is the turbulence energy profile; and the third is the dissipation rate profile. AUTOPLOT USE file phi 5 da 1 w1;col9 1 msg Velocity (W1) profile msg Press RETURN to continue pause clear da 1 ke;col9 1 msg KE profile msg Press RETURN to continue pause clear da 1 ep;col9 1 msg EP profile msg Press e to END ENDUSE CHAR(CTURB,TLSC);BOOLEAN(VARLAM);VARLAM=T REAL(HEIGHT,WTOP,REY,TKEIN,EPSIN,MIXL,DTF) REAL(WAV,US,MASIN,DELT1,DELY,KFAC,AA) INTEGER(NY2,JJM,JJJ) HEIGHT=0.1;WTOP=1.0; REY=1.E5;WAV=0.5*WTOP ** US from data of El Telbany & Reynolds [1982] US=WAV*0.196/LOG10(REY);TKEIN=US*US/.3 MIXL=0.045*HEIGHT;EPSIN=TKEIN**1.5/MIXL*0.1643 GROUP 4. Y-direction grid specification ENULA=WAV*HEIGHT/REY ** define first dely from wall and the grid-expansion factor Kfac which defines a constant ratio of lengths of two adjacent cells. DELT1=0.5*ENULA/US;KFAC=1.08;DELY=DELT1/(0.5*HEIGHT) ** calculate NY from dely & Kfac AA=(0.5/DELY)*(KFAC-1.0)+1.0;AA=LOG(AA)/LOG(KFAC)+1.0001 NY2=AA;NY=2*NY2 ** define uniform grid initially IREGY=1;GRDPWR(Y,NY,YVLAST,1.0) ** compute expanding grid from south boundary over one half of the channel width YFRAC(1)=DELY DO JJ=2,NY2 + JJM=JJ-1 + DELY=KFAC*DELY + YFRAC(JJ)=YFRAC(JJM)+DELY ENDDO YFRAC(NY2)=0.5 ** create symmetrical grid in the second half of the channel JJJ=0 DO JJ=NY-1,NY2+1,-1 + JJJ=JJJ+1 + YFRAC(JJ)=1.-YFRAC(JJJ) ENDDO YFRAC(NY)=1.0;YVLAST=HEIGHT GROUP 7. Variables stored, solved & named SOLVE(W1);STORE(ENUT,LEN1);SOLUTN(W1,P,P,P,P,P,N) MESG( Enter the required turbulence model: MESG( CK - Chen-Kim low-Re k-e model MESG( LB - Lam-Bemhorst low-Re k-e model (default) MESG( KO - Wilcox low-re k-omega model MESG( READVDU(CTURB,CHAR,LB) CASE :CTURB: OF WHEN CK,2 + TEXT(CHEN-KIM KE_1D PLANE COUETTE FLOW :T205 + MESG(Chen-Kim low-Re k-e model + TURMOD(KECHEN-LOWRE);KELIN=1;TLSC=EP WHEN LB,2 + MESG(Lam-Bremhorst low-Re k-e model + TURMOD(KEMODL-LOWRE);KELIN=1;TLSC=EP WHEN KO,2 + TEXT(K-OMEGA_1D PLANE COUETTE FLOW :T205 + MESG(k-omega low-Re model + TURMOD(KOMODL-LOWRE);TLSC=OMEG + STORE(EP);EPSIN=EPSIN/(0.09*TKEIN) ENDCASE GROUP 8. Terms (in differential equations) & devices ** Deactivate convection for single-slab solution TERMS(W1,N,N,P,P,P,P);TERMS(KE,Y,N,P,P,P,P) TERMS(:TLSC:,Y,N,P,P,P,P) GROUP 9. Properties of the medium (or media) ENUL=ENULA ** test for ground-set enul IF(VARLAM) THEN + TMP1=CONST;TMP1A=0.0;ENUL=LINTEM ENDIF GROUP 11. Initialization of variable or porosity fields FIINIT(:TLSC:)=EPSIN;FIINIT(KE)=TKEIN PATCH(ICOUF,LINVLY,1,1,1,NY,1,NZ,1,1) INIT(ICOUF,W1,WTOP/HEIGHT,0.0) GROUP 13. Boundary conditions and special sources ** moving upper wall WALL(WALLN,NORTH,1,1,NY,NY,1,NZ,1,1);COVAL(WALLN,W1,LOGLAW,WTOP) ** stationary bottom wall WALL(WALLS,SOUTH,1,1,1,1,1,NZ,1,1) GROUP 15. Termination of sweeps LSWEEP=70;TSTSWP=-1;LITHYD=6 GROUP 16. Termination of iterations MASIN=RHO1*WAV*HEIGHT; RESREF(W1)=1.E-12*MASIN*WAV RESREF(KE)=RESREF(W1)*TKEIN; RESREF(:TLSC:)=RESREF(W1)*EPSIN GROUP 17. Under-relaxation devices DTF=0.1*ZWLAST/WAV RELAX(W1,FALSDT,DTF); RELAX(KE,FALSDT,DTF/4.) RELAX(:TLSC:,FALSDT,DTF/4.) GROUP 18. Limits on variables or increments to them VARMIN(W1)=1.E-10 GROUP 22. Spot-value print-out IYMON=2;NPLT=5;NZPRIN=1;NYPRIN=2;IYPRF=1 GROUP 24. Dumps for restarts STORE(FMU,REYT,REYN,FONE,FTWO);WALPRN=T