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51) click "Solution Method for Built-in Matrix >>" option. (See fig 4.1)

Fig 4.1 Dialog box for Matrix Solver

1. We will have matrix sweeps only in X and Y directions, so check the Matrix Sweeps in Directions: labeled checkbox and uncheck Z.
2. Check the checkbox for P, enter 6 as Number of Sweeps, leave Alternating Direction Implicit (ADI) method selected, as shown in Fig.3.6
3. Click "Apply".

52) Now click "Relaxation factor" option to specify the relaxation factors.

1. We would like to have Relaxation Factors of 0.3 for U, V, P, K, and E,; and 0.6 for P. By default the relaxation factor for all active variables is 0.5. The only exception is P (pressure) and that of P is 1.0. Hence we will change the relaxation factor of P, U, V, K and E as shown in fig 4.2



fig 4.2 Dialog Box for relaxation Factor

2. Click "Apply".

53) Now Click "Close" to close the Advanced Output Control Option window.

54) Click "Next >" to go to Runtime Control dialog window. (see Fig 4.3)

Fig 4.3 Runtime Control dialog window

55) Click "Solve >>" and dialog box appears see fig 4.4.

Fig 4.4 Steady State dialog box

 Specify the values as follows:

1. Select Customize "SOLVE' Command Options.
2. Specify Maximum and minimum number of steps as 1500 both, for fixed number of steps.
3. Click "Apply".

56) Click "Finish" and a message window appears as shown in fig 4.5. Click "Yes" to save the project.

Fig 4.5 Answer Message window

This concludes the setup of the problem. If it is not already, make the Commands File viewable. It should look like:

/==== PROBLEM IDENTIFICATION ====/ TITLe BackwardsFacingStep USER TutorialUser /==== GEOMETRY SPECIFICATIONS ====/ GRID 81 by 71 COORdinates X Y BLOCk format 1 header line file = 'BackwardsFacingStep.grd' LOCAte ID=BLOCK LIST 1 2 3 4 5 6 7 8 9 80 81 82 83 84 85 86 87 88 159 160 161 162 163 164 165 166 167 238 239 240 241 242 243 244 245 246 317 318 319 320 321 322 323 324 325 396 397 398 399 400 401 402 403 404 475 476 477 478 479 480 481 482 483 554 555 556 557 558 559 560 561 562 LOCAte ID=INLET WINDOW 2 10 2 70 /==== INITIAL & BOUNDARY CONDITIONS ====/ INLEt at X- for SubRegion ID=INLET OUTLet at X+ ;1.0 WALL at everywhere unless otherwise specified BLOCkage at ID=BLOCK SET U everywhere 1.0 SET V everywhere 0.0 SET P everywhere 0.0 SET K everywhere 0.01 SET E everywhere 0.111 BOUNdary condition U VALUe ID=INLET X- indep. var Y 20 sets in Table: $ Y U 0.0 0.0 1.0 0.0 1.1 0.656 1.15 0.695 1.2 0.718 1.3 0.759 1.4 0.789 1.5 0.817 1.7 0.869 2.0 0.925 2.4 0.98 2.8 1.001 3.2 1.002 3.6 1.0 4.0 1.0 5.0 1.0 6.0 1.0 7.5 0.999 8.2 0.942 9.0 0.0 BOUNdary condition K VALUe ID=INLET X- indep. var Y 20 sets in Table: $ Y K 0.0 1.0e-7 1.0 1.0e-7 1.1 0.007286 1.15 0.007429 1.2 0.006714 1.3 0.005429 1.4 0.005 1.5 0.004286 1.7 0.003714 2.0 0.002571 2.4 0.001286 2.8 0.000571 3.2 0.000571 3.6 0.000571 4.0 0.000571 5.0 0.000571 6.0 0.000571 7.5 0.000571 8.2 0.002286 9.0 1.0e-7 /==== FLUID PROPERTIES & CONSTANTS ====/ DENSity of FIRSt phase =1.0 VISCosity of fluid FIRSt phase 1.53E-03 /==== NATURE OF FLOW ====/ TURBulent model HRe Ke /==== SOLUTION OPTIONS ====/ LIMIT value of K; min: 1.0e-7; max: 1.0e+7 LIMIT value of E; min: 1.0e-7; max: 1.0e+7 MATRix Sweep in Direction(s) X Y MATRix P sweep 6 times using method: ADI RELAxation Factor; U=0.3;V=0.3;P=0.6;K=0.3;E=0.3;MU=0.3; /==== OUTPUT CONTROL ====/ SAVE U V P K E 'BackwardsFacingStep.sav' FORMatted DIAGnostic node at (15,5) frequency :(1) U RU V RV P K E CONVergence U GLOBal 1.0E-6 1 phase /==== RUNTIME CONTROL ====/ SOLVe STEADy-state Nmax=1500 ,Nmin = 1500 END

Fig 4.6 Command file.

57) Go to Menu option Run >> Run Project (fig 4.7)

Fig 4.7 Run Menu

It will start a Runtime console window as shown in fig 4.8

Fig 4.8 Runtime Console.

Please note that a Stop button is provided in case it is a long run and the solution tends to diverge. Taking a look at the solution graph, one can easily see the trend of the index with increasing steps.

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