Particle Image Velocimetry PIV Calibration Presentation A stepbystep

Particle Image Velocimetry (PIV) Calibration Presentation A step-by-step guide to calibrating a custom PIV system using PIVlab 1. 2.

Contents Equipment Configuration Physical Procedure PIVlab 1. 2 Analysis Procedure Results Sources of Error Conclusions Future Directions

Equipment Harvard Syringe Pump Model 33 Two, plastic 60 ml syringes with inside diameter (ID)of of 26 mm 2 m of clear rubber hose with an ID of 4. 5 mm T-valve Clear, glass or plastic tubing with of ID of 6. 25 mm and outside diameter (OD) of 7. 7 mm Buret Clamp Silicone PIV system

Configuration

Syringe Pump Procedure � 1. Accurately mark the glass tube at 32. 6 mm (calculated with the ID using πr²h) above the opening. This is 1 ml in the glass tube. � 2. Silicone all tubing joints, as not to allow any air to enter or exit the tube system. � 3. After silicone is cured, fill the PIV tank with water to desired level. � 4. Insert the glass tube into the water, slightly under the water’s surface. � 5. Using a level, plumb the glass tube to make it vertical.

Syringe Pump Procedure cont. 6. Program the diameter of the syringes and set pump to Continuous run 7. Program the syringe pump to 50 ml/hr. , which calculates to 0. 026 m/s (which is the maximum pumping rate for these syringes) 8. Turn on PIV system 9. Press “Run/Stop” on syringe pump 10. Record vortex 11. After experimentation, film a known distance for a calibration image

PIVlab 1. 2 Analysis Procedure: load images with sequencing style 1 -2, 2 -3, 3 -4, …

Select region of interest (ROI) just below the glass pipe opening

Image pre-processing, enable contrastlimited adaptive histogram equalization (CLACHE) and highpass filtering (highpass) CLACHE enhances contrast in the image Highpass sharpens the image and removes background signals

PIV settings: set interrogation area ([px] in both dimensions) to 24 and Step ([px] spacing between the centers of interrogation area) in both dimensions to 12

Analysis: analyze all frames

Post processing: set standard deviation (stdev) filter threshhold [n*stdev] to 8. Apply to all frames

Calibration: load calibration image and select reference distance along with time step

Plot: set display parameter to velocity magnitude, smooth data to 20% and apply to all frames

A few velocity calculation options… -0 - frame (represented as -0 -) is the moment the water is completely expelled from the tube into the aquarium Velocity is calculated by programming the flow rate (i. e. . 833 ml/s)*distance fluid traveled (i. e. 0. 0326 m) = 0. 026 m/s². Record the maximum velocity/frame 1. A running average: take 20 slides after -0 - and average the velocity calculations (smoothing data) 2. Only look at 1 frame and average the same frame for each run

Extractions: polyline analysis A polyline is a line segment that calculates each individual vector’s velocity. This is represented in a graph with the Yaxis as velocity and the X-axis as the distance on the line. The polyline can be drawn through the regions of highest velocity denoted by the color bar. Set parameter to Velocity magnitude and Type to Polyline Draw the line across the region with the highest velocity determined by the color-bar Plot data Record the velocity for that frame Repeat this process to take a running average

Extractions: polyline analysis

Torus volume Volume of a torus is 2π²(D/2)r². Mass is calculated using the density of H 2 O at room temp. Smooth the data to 100%. Torus picture courtesy of: http: //blog. teachersource. com/2012/01/

Measure distance and angle: measure radius (D/2) from core to core

To insure accurate measurement of radius r, take 6 measurements from the same side of the torus half from the core to the outside wall and average them: radius 1

Radius 2…

Radius 3… repeat 3 more times

Results

Results cont. 1 ml High Velocity (0. 026 m/s) Run 1 ml Low Velocity (0. 016 m/s) 1 ml High 1 ml Low High Velocity Torus Acceleration Velocity Volume (ml) (m/s²) Force (N) High Velocity Work (J) Low Velocity Low Acceleratio Velocity n (m/s²) Force (N) Work (J) 1 0. 027 0. 015 1. 029 0. 978 5. 21 0. 00534 3. 20 E-05 3. 25 0. 00316 1. 90 E-05 2 0. 026 0. 021 0. 986 1. 015 5. 22 0. 00513 3. 07 E-05 3. 24 0. 00327 1. 96 E-05 3 0. 020 0. 023 0. 995 1. 021 5. 24 0. 00520 3. 12 E-05 3. 25 0. 00330 1. 98 E-05 4 0. 027 0. 019 1. 028 1. 023 5. 22 0. 00535 3. 21 E-05 3. 26 0. 00332 1. 99 E-05 5 0. 025 0. 017 1. 040 0. 998 5. 23 0. 00542 3. 25 E-05 3. 25 0. 00323 1. 94 E-05 0. 025 0. 019 1. 016 1. 001 SE 0. 0011 0. 0013 0. 0105 0. 0085 t -0. 434 2. 549 1. 519 0. 861 p <0. 05 Ave. Accel. (m/s²) Ave. Force (N) Ave. Work (J) 5. 22 3. 25 0. 00529 0. 00326 3. 17 E-05 1. 95 -05

Possible Sources of Error The Harvard Apparatus Twin Syringe Pump Model 33 has an accuracy within ± 0. 35% and reproducibility within ± 0. 1% The clear rubber hose may be expanding and contracting due to thermal fluctuations Convection currents with the experimental system

Conclusions All measurements using this 2 D PIV system are not statistically different from the expected values suggested by the syringe pump apparatus Although the Reynolds number (Re) for the syringe pump experiment is 162 and 100 for 0. 026 m/s and 0. 016 m/s, respectively, and the Re estimate for aquatic leaping in Rana catesbeiana is 16100, this method can be used to calculate force, work, and power of amphibian propulsion in an aquatic medium

Future Directions To use a static glass tube from the syringes to keep the water pressure constant To use larger syringes with a faster syringe pump will allow vortices to be produced at higher Re ranges, possibly within the frog aquatic leap velocities To produce a wider range of flow velocities Conduct experiment in a more temperature stable area

Acknowledgements �Undergraduate Students � Duane Barbano � Erik Dillingham � Antonia Tallante � Nicholas Gengler � Russell Nelson � Maxwell Wheeler �Graduate Students � Krysta Powers, M. S. student � Sang Hoon Yeo, Ph. D. student � Kari Taylor, M. S. student �Post-docs � Cinnamon Pace, Ph. D. � Jenna Monroy, Ph. D. Faculty Kiisa Nishikawa, Physiology, NAU Stan Lindtsted, Physiology, NAU Alice Gibb, Physiology, NAU Ted Uyeno, Biomechanics, VSU Brent Nelson, Mechanical Engineering, NAU David Lee, Biomechanics, UNLV Funding NAU VPR NAU GSG Sigma Xi GIAR Grant G 20111015158992 Personal Mr. Pippiens