1. Simulation of turbulent airfoil Flow Using FlowLab 1.1 (CFD PreLab 2)
Tao Xing and Fred Stern
IIHR—Hydroscience & Engineering
100 Hydraulics Laboratories
The University of Iowa
57:020 Mechanics of Fluids & Transport Processes
Dec 2, 2003

2. Outline Assignments for CFD PreLab2 and Lab2
What data you need prepare before coming to CFD Prelab2 and Lab2?
Detailed tutorial for simulating turbulent flow around airfoil using FlowLab 1.1
Other FlowLab functions
Data need to be saved for CFD report

3. Assignments for PreLab2 and Lab2
CFD PreLab2:
1. Run FlowLab using same conditions in EFD Lab 3.
2. Validate FlowLab predictions(pressure and lift coefficients) with EFD measurements
3. Inviscid flow vs. viscous flow
CFD Lab 2:
1. Parametric studies: effect of angle of attacks, effect of turbulent models, and effect of meshes.

4. Data need to be ready before PreLab 2 and Lab 2
EFD3 report, or EFD data:
1. Angle of attack
2. Chord length of the foil
3. Inlet velocity (or Re)
4. Air properties
5. Pressure coefficient distribution
6. Lift and drag coefficient
A floppy disk to save documents or figures
Slides 5~21 show a tutorial example

5. Tutorial Simulation conditions: 1. Foil: Clarky airfoil
2. Chord length: 1 foot (0.3048m)
3. Angle of attack: 12 degree
4. Domain: C type domain
5. Fluid properties: air at 22.4 degree,
density: kg/m^3
viscosity: e-5 kg/m.s
6. Inlet velocity: 7.04 m/s
7. Turbulent model: k-epsilon
8. Medium mesh
9. Double precision

6. FlowLab interface CFD process 1~6 CFD process: step 1, Geometry
Sketch window

7. CFD process: Step 1, Geometry
Units, SI recommended
Reset values to default ones
Create
Geometry
Go to CFD process, step 2
You are required to input the minimum parameters to create the geometry

8. CFD process: Step 1, Geometry
Geometry Created

9. CFD process: Step 2, Physics

10. CFD process: Step 2, Physics

11. CFD process: Step 2, Physics(BCs details)
Use uniform flow at inlet
Use default values

12. CFD process: Step 2, Physics(BCs details)

13. CFD process: Step 3, Mesh

14. CFD process, step 4, Solve Stop the calculation to
see intermediate results
Time history of residuals
Calculation will stop if either of the two parameters satisfied

15. CFD process, step 5, Reports

16. CFD process 5, reports (import EFD)

17. Reports (examples of results)

18. CFD Process, step 6, Post-Processing (Contours)
Choose the
contour variables

19. CFD Process, step 6, Post-Processing (streamlines)

20. CFD Process, step 6, Post-Processing (vectors)
Choose appropriate scale to view velocity vectors

21. EFD data format for FlowLab
(title "Pressure coefficient")
(labels "Position" "pressure coefficient")
((xy/key/label "experimental") )
Replaced with your
own EFD data!

22. Other functions Fit the view to full size
Align the geometry with coordinates

23. Other functions

24. Data need to be saved for report
CFD PreLab2: 1. time history of residuals (residuals vs. iteration number), 2. pressure and lift coefficients (both CFD and EFD); 3. contour of pressure (CFD), 4. contour of velocity, 5. velocity vectors(CFD), 6. streamlines
Detailed instructions, see assignments in Lab documents