Guest Blogger Miguel Palaviccinion Oct 05 in Guest Blogger by Meg
I’m not a professional photographer, far from that – I’m a professional student. To be more specific, I’m a PhD student/researcher studying Aerospace Engineering at the University of Florida. In the most general sense, I focus on enhancing the performance of aerodynamic bodies (airplanes, cars, submarines) by modifying the way that the flow (air or water) moves around the specific body.
When I started conducting experiments five years ago, I knew that in order to efficiently control any flow it was first in my best interest to understand the natural flow around the aerodynamic body of interest. I’m a visual learner, so naturally I gravitated toward learning flow visualization techniques. But how do you visualize air, how do you see something that’s invisible in it’s very nature? What tools and techniques do you use to capture events that change thousands and sometimes millions of times per second? And so, with a lab issued Nikon d70 and the kit 18- 70mm lens, my photographic journey began … Instead of boring you with the details of how photography went from a research tool to a passion, I thought I would provide some images that I have taken over the past four of years. Some of them were taken for my own research, while others were taken to benefit the research of my colleagues.
This was one of my first successful images that I took with a dSLR. It’s a three second exposure capturing the phenomena of flow separation over an airfoil at a high angle of attack. Using a fog machine I was able to inject micrometer sized particles into the flow. Then, to illuminate the particles, I created a light sheet by passing a laser beam through a spherical and then a cylindrical lens. To me, the beauty of this photo is that it captures a phenomenon we all experience daily but never get to see.
A colleague of mine asked me if it was possible to take an image of the alignment of six laser beams intersecting at a single location in space. Once aligned, we
moved the set-up into a wind tunnel and he used it to measure the velocity behind an aircraft landing gear. To capture this image, I used a flashlight during a three second exposure to illuminate the laser sources while keeping the contrast between the lasers and the background.
Using a mixture of highly viscous motor oil and fluorescent dye, I highlighted some of the flow features around a submerged sphere. I captured images at 15 second intervals and created a time lapse movie of the event. This image alone shows some of the complications that arise when trying to control a three-dimensional flow. I hope to also use this flow visualization technique to understand flow around the tips of wings (where highly three dimensional effects are prominent) in an effort to make wing-tip designs more efficient.
Sometimes my colleagues ask me to take images that will be used in conference presentations. For these, I usually have a little more leeway and can clean the image up in post – something that I cannot do with any image that will be published in a journal paper. In a nutshell, their research objective is to create low cost micro sensors to measure shear stress. To show the size of the sensor, I decided to place one sensor next to the tip of a pencil and another one on top of a popular snack around the lab.
Using photography in the lab setting has allowed me to get comfortable with a camera. In the last few years my passion for photography has spread from a work-related necessity to a passion I obsess about with every free minute hobby I partake in in my spare time. I’d like to thank LensProToGo for allowing me to share a bit of what got me into the world of photography. Oh, and if you know of any Aerospace job openings that need to be filled (especially those that deal with experimental fluid dynamics), feel free to let me know!
- Miguel Palaviccini, Interdisciplinary Microsystem Group: Graduate Research Assistant