Week 1: Internship Start

Hi, everyone! I started my internship this week! I learned a lot, experienced new things, and had fun. I used CAD software, a program Dr. Löhner coded, and ParaView to visualize fluid flows past objects. It was super cool! I included a picture below. I also met professors in the math department and watched a presentation on the fluid dynamics of cerebral aneurysms. Blood flow through the blood vessel, the aneurysm (a bulge in a weakened part of an artery wall), and the treatment method is modeled in order to improve current treatments. I had not imagined before the interaction between biomedical sciences and computational fluid dynamics, so I am very interested in this research. I also began coding a program to optimize a heating element (to achieve a desired temperature distribution), and I am now adding constraints to it. A big thank you to Dr. Löhner, who has been very helpful in this project, talking me through not only solutions, but an understanding of the problem itself.

For my independent research, I found topographical maps of Fairfax County created with LiDAR (Light Detection and Ranging, where laser pulses are used to measure distance to the ground and create detailed topographical maps of the land features). These maps are freely available on the Fairfax County website, and they have contour intervals of one foot! I was expecting the maps not to be very useful, since I was expecting contour lines of ten or maybe (hopefully) five feet, but the precision in these maps is extremely useful to me in analyzing the terrain around the Refuge, and I am happily surprised. I will examine how water flows through the area using these topographical maps, along with satellite imaging and on-the-ground investigation (visiting the Refuge) to identify porous/non-porous areas. I will also possibly go to the Refuge during the next rainstorm to observe.
See you next week,
Daria

Picture credit: Dr. Löhner helped me set up this model of fluid flow past a cylinder at George Mason University Center for Computational Fluid Dynamics. It was modeled with CAD and displayed with ParaView. The top box shows pressure, and the bottom velocity. You can see vortex shedding/a Kármán vortex street (oscillating low-pressure areas behind the cylinder, which cause an oscillating pattern in the fluid flow) as the fluid moving around the top and bottom of the cylinder interacts. Vortex shedding also explains things like ‘singing’ power lines in certain wind conditions and swirling cloud patterns downwind of islands. If you think vortex shedding is as cool as I do, google the science behind it!