How do Dandelions Spread their Seeds? скачать в хорошем качестве

How do Dandelions Spread their Seeds?

How are dandelion seeds able to travel distances of over 150km across oceans, with only small feathery bristles and the power of the wind? According to research by Cathal Cummins at the University of Edinburgh, the answer can be found in the fluid dynamics of the air flow around the plants 'micro-parachute', and in the future it could lead to improved flight for miniaturised vehicles such as drones. Interview with University of Oxford Mathematician Dr Tom Crawford. This video is part of a collaboration between FYFD and the Journal of Fluid Mechanics featuring a series of interviews with researchers from the APS DFD 2017 conference. Sponsored by FYFD, the Journal of Fluid Mechanics, and the UK Fluids Network. Produced by Tom Crawford and Nicole Sharp with assistance from A.J. Fillo. For more maths related fun check out Tom's website https://tomrocksmaths.com/ Get your Tom Rocks Maths merchandise here: https://beautifulequations.net/collec... ------- Follow Tom: Website: https://tomrocksmaths.com/ YouTube:    / tomrocksmaths   Twitter:   / tomrocksmaths   Facebook:   / tomrocksmaths   Instagram:   / tomrocksmaths   Follow FYFD on: Website: http://fyfluiddynamics.com Twitter:   / fyfluiddynamics   Patreon:   / fyfd   FYFD Supporters: http://fyfluiddynamics.com/supporters Follow JFM on: Website: https://www.cambridge.org/core/journa... Youtube:    / cambridgeupacpro   Twitter:   / jfluidmech   Follow the UK Fluids Network on: Website: https://fluids.ac.uk/ Twitter:   / ukfluidsnetwork   Follow Nicole: Website: http://nicolesharp.com Twitter:   / aerognome   -------- Featuring: C. Cummins et al. "The miniature parachute of the dandelion fruit” http://meetings.aps.org/link/BAPS.201... At the low Reynolds number at which small plant fruit (the seed-bearing structure in flowering plants) fly, there are a variety of modes of flight available: from parachuting to gliding and autorotation. Here we will explore the aerodynamics of small plumed fruit (dandelions) that utilise the parachuting mode of flight. If a parachute-type fruit is picked up by the breeze, it can be carried over formidable distances. Incredibly, these parachutes are mostly empty space, yet they are effectively impervious to the airflow as they descend. In addition, the fruit can become more or less streamlined depending on the environmental conditions. In this talk, we will present results from our numerical and physical modelling that clarify how these tiny parachutes achieve such impermeability despite their high porosity. We reveal that the dandelion's parachute tunes its permeability to achieve the aerodynamic stability as it flies, which helps confer the fruit's incredible flight capacity. Nature publication: https://doi.org/10.1038/s41586-018-06... Nature article: https://www.nature.com/articles/d4158... Special Thanks To: Nicole Sharp A. J. Fillo Cathal Cummins NASA JPL US Navy