# Tutorial 10: Probabilistic Tutorial

Purpose/Objective

This exercise will walk the user through setting up a probabilistic run. The user will learn how to:

• Use Flow Simulator Probabilistic tool

Step 1: Objective

• The user will start with the existing S1B supply model and set up a probabilistic run to investigate the effects on swirl caused by changes in angle and area of an upstream element

Figure 1.01: Element and chamber of focus

• Browse to model location and select open (Probabilistic_start.flo)

Step 3: Building Model

1. Go to Probabilistic & DOE → Probabilistic

2. Set Number of Runs to 20
1. Under Group, select Element
2. Set ID to the Element ID upstream of the chamber of focus
3. Set Property to Tangential Angle
4. Set Dist. Type to Uniform
5. Enter a Lower Bound and Upper Bound of 60 and 80 respectively
1. Under Group, select Element
2. Set ID to the Element ID upstream of the chamber of focus
3. Set Property to Area
4. Set Dist. Type to Uniform
5. Enter a Lower Bound and Upper Bound of 0.04 and 0.05 respectively
5. Click Generate Table & Save Multicase File and name it table_angle_area.txt

Figure 1.04: Generated table of tangential angle values

6. Go to Solver → Analysis Setup → Solvers Convergence and set Maximum Number of Iterations to 500 and Save
7. Under the Run Flow Simulator tab, click the “…” at the end of Run Table line and browse to the table_angle_area.txt file created earlier

Figure 1.05: Generated table of tangential angle values

8. Click Run Flow Simulator

Figure 1.06: Readout of run cases

9. Create a Variable in the Variable Edit Tree for the Transfer Function
1. Go To PreProcessing → Model Parameters → Variable Editor
2. Right Click in Variable Edit Tree and click Add Variable
3. Name the Variable SWIRL
4. Right Click on the Variable Name SWIRL and select “Set Expression”

5. Click “Insert Result Variable”
6. Select Chamber, 8, Swirl and then Insert Expression

7. Click “Execute”
10. Click “Create Transfer Functions” in the Flow Simulator Probabilistic Window
1. Set inputs as shown below and click “Create Transfer Function”

2. The Transfer Function Equation is the relationship between the element area and angle to the downstream chamber swirl.
11. Click “Run Transfer Functions” in the Flow Simulator Probabilistic Window
1. Click “Check All” and “Predict”

2. This shows the results of the trasfer function equation for each of the 20 cases run.

12. Another Way to Post Process: Go to PostProcessing → Results Table
13. Under Results, click , select the Elements radial button and enter the element ID of the element with varying tangential angle
14. Select Append and go to the Inputs tab
1. Choose Tangential Angle (EL_THETA,22)
2. Choose Area (area, 202)
15. Select and choose the chamber downstream of the changed element
16. Select Append and go to the Results tab
• Choose Swirl Value

Figure 1.07:Results Table showing Tangential Angle and Swirl Value

17. Highlighting two columns and clicking show plot will create a line a plot of both values and also a “Scatter Plot” button. Clicking that button will create a plot seen in Figure 1.08

Figure 1.08: Scatter plot of swirl value vs area

18. Hovering over the points will show the values from the table that correspond to the point