GROUP 1. Run title and other preliminaries TEXT(CHEN-KIM K-E_1D PLANE COUETTE FLOW :T100 TITLE mesg(PC486/50 time last reported as appx. 30.sec DISPLAY The problem considered is turbulent couette flow in a plane channel with one moving wall. The shear stress is uniform across the flow and hence the axial pressure-gradient is zero. The velocity profile has an S-shape and is symmetrical about the central plane, and so the average velocity is one half of the velocity of the moving wall. In the calculation made here the Reynolds number is 1.E5 and it is based on the channel height and the average velocity. ENDDIS Calculations with the standard k-e model plus wall functions show that the turbulent kinetic energy k is essentially uniform across the flow. This result is in accordance with the exact solution of the k-e model equations reported by Henry and Reynolds [1984], but not with the experimental data reported in the literature, which shows that k is about 70% larger near the walls than it is at the centre plane. Gibson [1988] and Schneider [1988] have demonstrated that the inclusion of a counter-gradient diffusion term in the k-equation leads to very good agreement the measured k profiles. Calculations may be made with the high-Re forms of either the k-e model, the Chen-Kim k-e model, the RNG k-e model, and the Wilcox k-omega model. For this case all models produce similar results. The following AUTOPLOT use file produces two plots; the first is the axial velocity profile; and the second is the turbulence energy profile. AUTOPLOT USE file; phi 5 cl; da 1 w1; col9 1 msg Velocity (W1) profile; Press RETURN to continue pause; cl; da 1 ke; col9 1; scale y 0. 2.e-3; redraw msg KE profile. Press RETURN, then e to END pause ENDUSE CHAR(CTURB,TLSC) REAL(HEIGHT,WTOP,REY,TKEIN,EPSIN,MIXL,DTF,WAV,WSTAR,MASIN) HEIGHT=0.1;WTOP=1.0; REY=1.E5;WAV=0.5*WTOP ** wstar from data of El Telbany & Reynolds [1982] WSTAR=WAV*0.196/LOG10(REY);TKEIN=WSTAR*WSTAR/.3 MIXL=0.045*HEIGHT;EPSIN=TKEIN**1.5/MIXL*0.1643 GROUP 4. Y-direction grid specification ENUL=WAV*HEIGHT/REY;NY=30;YVLAST=HEIGHT;GRDPWR(Y,NY,YVLAST,1.0) DTF=20.*ZWLAST/WAV 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( CHEN - Chen-Kim k-e model (default) MESG( KE - Standard k-e model MESG( KO - Wilcox k-o model MESG( RNG - RNG k-e model MESG( READVDU(CTURB,CHAR,CHEN) CASE :CTURB: OF WHEN CHEN,4 + MESG(Chen-Kim k-e model + TURMOD(KECHEN);KELIN=1;TLSC=EP WHEN KE,2 + TEXT(K-E_1D PLANE COUETTE FLOW :T100 + MESG(Standard k-e model + TURMOD(KEMODL);KELIN=1;TLSC=EP WHEN KO,2 + TEXT(K-OMEGA_1D PLANE COUETTE FLOW :T100 + MESG(k-omega model + TURMOD(KOMODL);TLSC=OMEG + STORE(EP);EPSIN=EPSIN/(0.09*TKEIN) WHEN RNG,3 + TEXT(RNG K-E_1D PLANE COUETTE FLOW :T100 + MESG(RNG k-e model + TURMOD(KERNG);KELIN=1;TLSC=EP + STORE(ETA,ALF,GEN1) + OUTPUT(ALF,Y,N,P,Y,Y,Y);OUTPUT(ETA,Y,N,P,Y,Y,Y) + DTF=2.*ZWLAST/WAV ENDCASE GROUP 8. Terms (in differential equations) & devices Deactivate convection 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 11. Initialization of variable or porosity fields FIINIT(W1)=0.5*WTOP;FIINIT(:TLSC:)=EPSIN;FIINIT(KE)=TKEIN 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=10;LITHYD=20 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 VARMIN(W1)=1.E-10;WALPRN=T GROUP 22. Spot-value print-out IYMON=NY-2;NPLT=1;NZPRIN=1;NYPRIN=1;IYPRF=1;TSTSWP=-1 GROUP 24. Dumps for restarts RELAX(W1,FALSDT,DTF); RELAX(KE,FALSDT,DTF); RELAX(EP,FALSDT,DTF)