Celebrating the physics of all that flows with Nicole Sharp, Ph.D.
- Profile
Sochi 2014: Ski Jump, Part 2
Yesterday we talked about the technique ski jumpers use to fly farther. Generating lift without too much drag is the key to a good jump. But jumpers are subject to ever-changing wind conditions, and those can help or hurt them. Unlike most sports, in ski jumping a headwind is desirable. This is because the added…
Sochi 2014: Ski Jump
Great ski jumpers are masters of aerodynamics. There are four main parts to a jump: the in-run, take-off, flight, and landing. An athlete’s aerodynamics are most vital in the in-run and, naturally, the flight. During the in-run, the athlete is trying to gain as much speed as possible, so she tucks down and pulls her…
Sochi 2014: Speedskating Suits
Long track speed skating is a race against the clock. Skaters reach speeds of roughly 50 kph, so drag has a significant impact. This is why skaters stay bent and spend straightaways–their fastest segments on the ice–with their arms pulled behind them. It’s also why their speedsuits have hoods to cover their hair. This year…
Sochi 2014: Luge
Like athletes in many of the gravity sports in the Winter Olympics, lugers want to be as aerodynamic as possible to minimize their drag. Once a luger has started sliding, only gravity can increase their speed – every other force, from friction to drag, pulls away valuable time. Luge sleds are built on sharp runners…
Sochi 2014: Why is Ice Slippery?
Ice is a key component of many Winter Olympic disciplines, including figure skating, hockey, speed skating, curling, and the sliding sports. The low friction and slippery nature of the ice are vital to the events, but oddly enough, scientists don’t yet fully understand why ice is slippery. A common explanation is that the narrow blades…
Sochi 2014 Incoming
The Winter Olympics are underway in Sochi, Russia, and here at FYFD, I am busy preparing a special series of posts on fluid dynamics in the Winter Games. Look for the first of those starting on Monday. In the meantime, you can check out some of FYFD’s previous themed series now compiled into a special…
Convective Impressionism
Buoyant convection, driven by temperature-dependent changes in density, is a major force here on Earth. It’s responsible for mixing in the oceans, governs the shape of flames, and drives weather patterns. The images above show flow patterns caused by buoyant convection. The colors come from liquid crystal beads immersed in the fluid; red indicates cooler…
The Reynolds Experiment
One of the most famous and enduring of all fluid dynamics experiments is Osborne Reynolds’ pipe flow experiment, first published in 1883 and recreated in the video above. At the time, it was understood that flows could be laminar or turbulent, though Reynolds’ terminology of direct or sinuous is somewhat more poetic: Again, the internal motion…
Wind and Waves Visualized
Much like the wind map we featured previously, designer Cameron Beccario’s visualizations of wind and ocean surface current data draw from near-real-time sources to create a stunning picture of fluid dynamics on a planetary scale. The number of options in terms of projections and data are really quite incredible, and you’ll want to play around…
Protostellar Jets
As young stars form, they often produce narrow high-speed jets from their poles. By astronomical standards, these fountains are dense, narrowly collimated, and quickly changing. The jets have been measured at velocities greater than 200 km/s and Mach numbers as high as 20. The animation above (which you should watch in its full and glorious…