UKFN Videos 30/11/17 shortlist: Recent Episodes
Cambridge University
A solid sphere impacts a thin polymer sheet floating at an air-liquid interface. The video is slowed down 200 times.
This is a video showing a liquid droplet rolling up on a flexible microfluidic device, in which droplet flows along the slope formed by simply bending-deforming a 600 micron thick aluminium (Al) plate. The droplet was remotely pushed up by the acoustic wave propagating along the Al plate surface, which is generated by a thin layer of ZnO film (with electrode onto it).
This is a video of a novel experiment where photoelastic discs are rolled down a narrow, inclined chute. Here the forces exerted when discs interact can be measured from the intensities of the light they transmit with the aim of investigating how stresses are distributed within avalanches.
This video shows the transfer of mechanical energy and radiative pressure from Surface Acoustic Wave (SAW) travelling onto a solid surface into a droplet of water, dropped in the propagation path of SAWs, at 100k fps acquisition (slowed down 500 and 1500 times). The behaviour resembles an eruption and is used in medicine nebulisers.
An 18mm-diameter, 1mm cross-section Latex ring floats on the surface of the water in a funnel. The water is slowly removed, the surface area decreases and the ring is compressed and buckles.
When a solid sphere hits an elastic sheet floating on the surface of water, wrinkles form and a capillary-like ripple propagates. The ripple propagates and the wrinkles grow with time — all due to an interplay between the elasticity of the sheet and the inertia of the fluid.
An experimental investigation is carried out to study particle entrainment processes (including rolling, hopping and saltation) under well controlled conditions, for a number of particle densities (ρ_s>1100kg/m^3), flow regimes (Re>10^6) and bed roughness arrangements.