6. Synthetic PIV recording pair to simulate circular channel flow 

Edpiv pE 2013 simulatiom example

PART I: Create synthetic PIV recording pair

- Execute edpiv.exe to open EDPIV start window;

- Select menu “File \ New image” ;

- Input new image size as: Width=1024, Height=1024, and press “OK” button;

- Press button “Processing” to open “Image processing” window;

- Select menu “Tools \ Simulation settings \ Flow” to open dialogue box “PIV recording simulation settings”;

- Set amplitude as: Ax=0, Ay=0, Az=0

- Ignore other parameters in section “I:Periodical/4-roll-mill/shear/pipe”

- Set parameters in section “II: Solid body rotation & potential flow” as
Radius [pix]: r1=256, r2=460
Position: X=550, Y=480
Boundary layer thickness [%]: 20
Rotation angle [1/100 degree] : 100
Mask: Pipe

- Set “III: Uniform flow velocity” as X: 0, Y: 0, Z: 0

- Press “OK” to close dialogue box “PIV recording simulation settings”;

- Select menu “Tools \ Simulation settings \ Particle” to open dialogue box “Particle image simulation” ;

- Setup parameters as
Number/(32x32 pix) : 20
Max. diameter [pix] : 5
Min. diameter [pix] : 2
Max brightness : 250
Min. brightness : 127
Extended view (%) : 5
Ry/Rx : 1
Orientation : 0
Particle mode : Quik
PTV : not checked;

- Press “OK” to close dialogue box “Particle image simulation” ;

- Select menu “Noise” to open dialogue box “Image noise simulation”;

- Setup parameters as
Random background noise - Intensity: 10
Random background noise - Mean value: 60
Brownian motion - Intensity : 0
Low frequency background noise - Intensity : 0

- Close dialogue box “Image noise simulation”;

- Select menu “Tools \ One par”

- Answer “Yes” to question “Do you want to simulate a PIV recording pair?”

- Wait until the synthetic images are created - the first PIV recording is displayed in the window;

- Save the first PIV recording by selecting menu “File \  Export image”

- Press button “I” to display the second synthetic PIV recording in the window;

- Save the second PIV recording by selecting menu “File \  Export image”

- Press button “I” to display the boundary mask (i.e. Mask B) in the window;

- Save Mask B by selecting menu “File \  Export image”

- Close “Image processing window”

 

PART II: Evaluate the synthetic PIV recording pair

- Open recording 1 and 2 and import B-mask in the start window - (This step may be skipped if they are already in the window);

- Press button “Evaluation” to open “Evaluation” window;

- Select menu “Edit / Evaluation settings” in to open the “Evaluation settings”  window;

- Set up parameters as follows
Method & algorithm: PIV

Ellipse window: Not selected
Boundary mask: Selected

Recording type: Single recording (pair)
Exposure type: Single
Flow type: One phase
Initial window shift: X=0, Y=0
Interrogation grid:
32x16
Limits for error detection & correction: Dx=3, Dy=3
Iteration number: 0 (Initial), 6 (Final) 
Window width: 48 (Initial), 48 (Final) 
Window height: 24 (Initial), 24 (Final) 
Search radius: 12

Adaptive interrogation window: Grid, Reshape selected   

- Close “Evaluation settings” window.

- Select menu “Edit \ Grid structure \ Regular” to open dialogue box “Regular evaluation grid”;

- Press button “Reset grid”  and then press button “OK”;

- Select menu “Edit \ Grid reconstruction \ Circular channel”

- Click menu “Start” in “Evaluation” window;

- Answer “Yes” to question “Do you want to start an evaluation?”;

- Press button “OK” to close the dialogue box that notices the end of the evaluation.