Kit Wilkinson , Ted Uyeno, Kiisa Nishikawa, Russell Nelson

1. An economical and open-source particle image velocimetry (PIV) instrument for use in a secondary and higher education setting Kit Wilkinson, Ted Uyeno, Kiisa Nishikawa, Russell Nelson Laser Photo: http://laserpointerforums.com, Photographer: joshv

2. Outline Introduction and History of PIV ------- Parts and Details ------------------------ How to Build the System ------------------ Website and Acknowledgments ------- Pterosaur image - http://hoopermuseum.earthsci.carleton.ca/saleem/creatures.htm Ornithopter image - http://www.ornithopter.net/history_e.html Flyer image - http://www.wright-brothers.org/Information_Desk/Help_with_Homework/Help_with_Homework_Intro/Help_with_Homework_Intro.htm Jetliner image -http://kopeikingallery.com/exhibitions/view/aircraft-1

3. Introduction • What is particle image velocimetry? • PIV is an optical method to visualize fluid flows. • PIV can measure the velocity of fluids and reveal fluid properties. • PIV is used in aerodynamics and hydrodynamics to research how organisms swim, fly, and conduct fluids in the body and to design aircraft, submarines, cars, prosthetic hearts, etc. • New PIV Systems can cost as much as $100,000. • You can build your own for less than $1,000.

4. A Brief History of PIV • Leonardo daVinci (1452-1519) observed and sketched flow fields over differing objects in a stream. • Ludwig Prandtl (1875-1953), a German scientist, built a flow tunnel in sunlight, in which he photographed fluid flows. • In 1903 he published, Fluid Flow in Very Little Friction, where he described the boundary layer. • This study described the relationship of drag and streamlining, and gave a description of stall, which is the inverse relationship between wing angle of attack and lift.

5. Ludwig Prandtl’s Tank daVinci’s Fluid Field Sketch http://www.sciencegallery.com/sts http://www.talkmoneycafe.com/?p=612 http://www.sciencebuzz.org/buzz-tags/ludwig-prandtl Prandtl’s Foil Experiment

6. Basic Parts of a PIV System • Transparent tank or chamber • Fluid • Power supplies • Laser light at 532nm (Green) or 650nm (Red) • Optics • Isobuoyant particles ranging in size from 20µm-100µm • Sieve system • High speed video camera and lenses • Microprocessor (Synchronizer) and Protoshield • Computer • PIV software • Electronics, wires, and tools

7. Basic Setup of a PIV System http://www.dantecdynamics.com/Default.aspx?ID=820

8. Tanks, Fluid and Power Supplies • Tanks can be aquariums of glass or Plexiglas - $15. • The surfaces should be flat to prevent distortion of the laser light and images. • The fluid should be distilled water to start out with. • Power supplies should not be batteries as to keep the laser light brightness constant - $20. • Old PC power supplies can be harvested and retrofitted with a Sparkfun Benchtop Powerboard Kit to supply 3.3, 5, 12 and -12 volt power . http://www.sparkfun.com/products/9774

9. PC Power Supply Benchtop Power Supply Kit ATX Connector

10. Lasers and Optics • High powered laser pointers are an inexpensive solution to the light requirements for small PIV systems - $50 X 2. • These lasers are DANGEROUS to the human eye and can cause retinal damage. • Lasers are UltraFire 0.3-0.4w, 532nm laser pointers. • Optics can be harvested from laser levels, guides and markers to produce a laser light sheet - $5 X 2. • Some laser levels have press-fitted optics and are very difficult to remove. • Laser marker optics seem to be easier to harvest. Central Machinery laser markersare sold from Harbor Freight Tools.

11. UltraFire 0.8W 532nm Laser Pointer Central Machinery Laser Marker Optics

12. Isobuoyant Particles and Sieving • Particles can be oils, styrofoams, hollow glass spheres, or dehydrated blue-green algae - free - $15. • Pliolite, a form of styrofoam is a great particle. • Try styrofoam or blue-green algae pills to start out with. • A blender will break particles up and a sieve shaker will size the particles between 20µm and 100µm in diameter - $50. • If a sieve shaker is not available, use a set of sieve tubes and place them on a fish tank air pump.

13. Sieve Tubes

14. High Speed Camera and Lenses • The high speed video camera must have a TTL signal output, data output, and a trigger - $200 to ?. • Phantom, Redlake and NAC are manufacturers of high speed cameras. • The lens must have a large aperture to allow a maximum amount of light to enter the camera - $100. • The focal ratio or f-number on the camera should be 2.0 or less. 30-80mm lenses seem to work within the space confines of the PIV system.

15. Phantom High Speed Camera Nikon AF Nikkor lens with 1.4 f-number http://www.emeraldinsight.com/journals.htm?articleid=1464093&show=html

16. Microprocessor, Computer, and PIV Software • The microprocessor Arduino can be used as a synchronizer with a ProtoShield - $65. • You can download our custom programming. • A PC or Mac can be used to run the camera and PIV software. • PIV software is free! Several universities have written and produced open source PIV software. • PIV Lab, OpenPIV, JPIV. • Some of these programs require MATLAB or Python to run, some do not.

17. How to Build the System: Particles • The particles must be ground in a blender and sieved. • The particles then are added to the water. 0.25gPliolite/gallon of water was a good density to start out with. • A drop of dish soap sometimes was necessary to allow the particles to mix evenly throughout the tank. • The sheets of laser light must be aligned to brighten the particles.

18. General Wiring

19. How to Build the System: Electronics • The lasers must have the optics glued directly in the center of the beam. • The lasers must be wired to the synchronizer. • The synchronizer receives 5v and 12v power. The 5v is then pulsed to the lasers from the camera’s signal. The synchronizer also must have an input from the computer with a USB cable. • The signal cable is connected from the camera to the synchronizer.

20. Electronics continued • An external or internal software trigger may be used. • The camera software should be ready to capture the images. The video file needs to be converted to single image files. • The single image files are then imported to the PIV software for analysis.

21. General Wiring TTL Input Arduino Protoshield Breadboard 3.3v 12v USB Input MOSFET Chip

22. Wiring Details

23. General Setup Computer 20 Gallon Aquarium Lasers Data Input Lens Camera and Lens

24. Contact and Website • Name - Kit C. Wilkinson • Email - kit.c.wilkinson@gmail.com, kcw53@nau.edu • Website - http://OpenSourcePIV.weebly.com • This presentation will be posted on the website • Special notes will be included as questions arise • The website is currently basic, it will be come more advanced with use • Total cost of entire system is $925 - ? • Teacher grants are available from Sigma Xi

25. Acknowledgments Undergraduate Students Russell Nelson Daniel Kmack Duane Barbano Erik Dillingham Antonia Tallante Nicholas Gengler Graduate Students Leslie Gilmore, PhD. student Krysta Powers, M.S. student Kari Taylor, M.S. student Post-docs Cinnamon Pace, Ph. D. Jenna Monroy, Ph.D. Professional Eliokem Inc. Trelleborg Group 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 Sandra Nauwelaerts, Biomechanics, UA Eize Stamhuis, Engineering, UG Funding NAU VPR NAU GSG Sigma Xi GIAR Grant G20111015158992 Personal Janelle I. Wilkinson