Aviation
Below are a few shots taken by some of my passengers.
I am an instrument-rated private pilot, and have flown the following aircraft:
Some of my favorite flights have been to Kelleys Island, Cedar Key, and around the San Juan Islands.
I spend most of my time in a C172S, so I created a quick Web app for calculating weight, balance, and performance. I also have included a C152 for good measure. I'll eventually make other airplanes available.
Gainesville Regional (KGNV)
UF Football Stadium
Flying in the St. Augustine area.
Left (or top): Cedar Key Airport. A cab driver monitors the radio traffic frequency, and will ask whether you need a lift into town!
Right (or middle): Views of Florida's rivers and streams. This was also taken near Cedar Key.
Bottom: Landing at Cedar Key
Top left: I am flying a Cherokee Warrior II over the San Juan Islands. Top right: San Juan Islands.
Bottom: Mt. Baker as viewed flying over the San Juans.
Preflighting a C172S in Gainesville, FL
Preflighting a DA20 in Akron, OH
Because I am a fluid dynamicist and a computational astrophysicist, I spend a lot of time writing code. Part of my research focuses on aerodynamics of particles embedded in gaseous and dusty planet-forming disks. The types of problems I investigate are illustrated by the image below.
The plot shows the temperature structure arising from a bow shock around a 2000 km planetoid (a piece of a forming planet). The 3D calculation is performed using a code that I wrote (paper in progress), with a gas speed of 7 km/s in the frame of the planet and a pre-shock gas density of 1e-9 g/cc. This particular run includes a detailed equation of state for molecular hydrogen (rotational and vibrational modes, as well as dissociation), i.e., the adiabatic index is not simply 1.4. Vibrational modes and dissociation help to regulate the temperature of the shock structure. The white lines show trajectories for 0.3 mm solids that encounter the shock, while cyan shows 1 mm solids. The 1 mm objects are mostly accreted for cross-sections smaller than the planetoid's radius due to the longer stopping/re-coupling time, which is the time it takes for a particle to become entrained with the gas flow.
Well, why not use this code to explore flight characteristics? To the left is a simple, symmetric airfoil with a cord length of 150 cm, a width of 15% cord, and a max width at 20% of the cord. The airfoil has a 4 degree angle of attack (AOA) in the simulation, with a wind speed of 80 knots in the x direction. The colorbar shows the difference in pressure in (in-Hg), relative to 29.8 in-Hg. There is a clear pressure difference across the bottom and top of the airfoil. There is some disruption of flow due to the Cartesian grid cell construction (think of an airfoil built out of Legos), but this is minor (particular for this purpose). I am working on including cut-cells in my code, which would allow for better treatment of arbitrary obstructions on the grid.
We can estimate the coefficient of lift by calculating the incident pressure on the airfoil in the direction of gravity (in this case in the up-down direction). The figure below shows the pressure in millibars as a function of the x-direction above. The blue +'s show the pressure at a given x on the top and bottom of the airfoil. Because the top of the airfoil has lower pressure, the lower blue points correspond to the physical top. The black triangles show the average pressure for a given x. The area within the blue +'s can be related to the density of the atmosphere and the wind speed to derive the coefficient of lift, which for this case, is about 0.27.