FYFD

Month: December 2019

  • Surfing Honeybees

    Surfing Honeybees

    Honeybees have superpowers when it comes to their aerodynamics and impressive pollen-carrying, but their talents don’t end in the air. A new study confirms that honeybees can surf. Wet bees cannot fly–their wings are too heavy for them to get aloft when wet–but falling into a pond isn’t the end for a foraging honeybee.

    Instead, the bee flaps its wings, using them like hydrofoils to lift and push the water. This action generates enough thrust to propel the bee three body lengths per second. It’s a workout the bee can only maintain for a few minutes at a time, but researchers estimate honeybees could cover 5-10 meters in that time. Once ashore, the bee spends a few minutes drying itself, and then flies away no worse for the wear. (Image and research credit: C. Roh and M. Gharib; via NYTimes; submitted by Kam-Yung Soh)

  • Adapting to the Flow

    Adapting to the Flow

    Simulating fluid dynamics computationally is no simple task. One of the major challenges is that flows typically consist of many different lengthscales, from the very large to the extremely tiny. In theory, correctly capturing the physics of the flow requires computing all of those scales, and that means having a very close, dense grid of points at which the physics must be calculated during every time step of a simulation. Even for a relatively simple flow, this quickly balloons into a prohibitively expensive problem. It simply takes a computer far too long to calculate solutions for so many points.

    One technique that’s been developed to save time is Adaptive Mesh Refinement. You can see an example of it above. The background is a grid of points that are far from one another in places where the flow isn’t changing and are tightly spaced in areas where the rising flames are most changeable. Adaptive Mesh Refinement algorithms automatically change these grid points on the fly, adding more where they’re needed and subtracting them where they aren’t. The end result is a much faster computational result that doesn’t sacrifice accuracy. Check out the videos below for some examples of this technique in action. (Video and image credit: N. Wimer et al.)