Simulation of turbulent airfoil Flow Using FlowLab 1.1 (CFD PreLab 2)

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Simulation of turbulent airfoil Flow Using
FlowLab 1.1 (CFD PreLab 2)

• Tao Xing and Fred Stern
• IIHRHydroscience Engineering
• 100 Hydraulics Laboratories
• The University of Iowa
• 57020 Mechanics of Fluids Transport Processes
• http//css.engineering.uiowa.edu/fluids/
• Dec 2, 2003

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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

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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.

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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 521 show a tutorial example

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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 1.1949 kg/m3
• viscosity 1.8320e-5 kg/m.s
• 6. Inlet velocity 7.04 m/s
• 7. Turbulent model k-epsilon
• 8. Medium mesh
• 9. Double precision

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FlowLab interface
CFD process 16
CFD process step 1, Geometry
Sketch window
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CFD process Step 1, Geometry
Units, SI recommended
Reset values to default ones
Go to CFD process, step 2
Create Geometry
You are required to input the minimum parameters
to create the geometry
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CFD process Step 1, Geometry
Geometry Created
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CFD process Step 2, Physics
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CFD process Step 2, Physics
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CFD process Step 2, Physics(BCs details)
Use default values
Use uniform flow at inlet
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CFD process Step 2, Physics(BCs details)
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CFD process Step 3, Mesh
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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
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CFD process, step 5, Reports
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CFD process 5, reports (import EFD)
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Reports (examples of results)
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CFD Process, step 6, Post-Processing (Contours)
Choose the contour variables
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CFD Process, step 6, Post-Processing (streamlines)
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CFD Process, step 6, Post-Processing (vectors)
Choose appropriate scale to view velocity vectors
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EFD data format for FlowLab
(title "Pressure coefficient") (labels "Position"
"pressure coefficient") ((xy/key/label
"experimental") 0 -0.526354204 0.00381 -1.67029734
1 0.00762 -1.880839023 0.01524 -1.880839023 0.0228
6 -1.775568182 0.03048 -1.621170949 0.04572 -1.438
701491 0.06096 -1.291322314 0.09144 -1.221141754 0
.12192 -0.708823662 0.1524 -0.652679213 0.18288 -0
.505300036 0.21336 -0.385993083 0.24384 -0.2175597
38 0.27432 -0.098252785 0.27432 0 0.24384 -0.00701
8056 0.21336 0.03509028 0.18288 0.021054168 0.1524
0.063162504 0.12192 0.112288897 0.09144 0.1473791
77 0.06096 0.224577794 0.04572 0.245631962 0.03048
0.273704186 0.02286 0.315812522 0.01524 0.4491555
87 0.00762 0.603552821 0.00381 0.870238951 )
Replaced with your own EFD data!
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Other functions
Fit the view to full size
Align the geometry with coordinates
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Other functions
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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