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Nicole SharpSalt Fingers <a class="" href="https://fyfluiddynamics.com/wp-content/uploads/DDinsta1.png" rel="nofollow noopener" target="_blank"></a> <a class="" href="https://fyfluiddynamics.com/wp-content/uploads/DDinsta2.png" rel="nofollow noopener" target="_blank"></a> <a class="" href="https://fyfluiddynamics.com/wp-content/uploads/DDinsta3.png" rel="nofollow noopener" target="_blank"></a> Any time a fluid under gravity has areas of differing density, it convects. We’re used to thinking of this in terms of temperature — “hot air rises” — but temperature isn’t the only source of convection. Differences in concentration — like salinity in water — cause convection, too. This video shows a special, more complex case: what happens when there are <a href="https://en.wikipedia.org/wiki/Double_diffusive_convection" rel="nofollow noopener" target="_blank">two sources of density gradient</a>, each of which diffuses at a different rate.The classic example of this occurs in the ocean, where colder fresher water meets warmer, saltier water (and vice versa). Cold water tends to sink. So does saltier water. But since temperature and salinity move at different speeds, their competing convection takes on a shape that resembles dancing, finger-like plumes as seen here. (Video and image credit: <a href="https://doi.org/10.1103/APS.DFD.2024.GFM.V2677989" rel="nofollow noopener" target="_blank">M. Mohaghar et al.</a>)<a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/2024gofm/" target="_blank">#2024gofm</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/convection/" target="_blank">#convection</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/double-diffusive-convection/" target="_blank">#doubleDiffusiveConvection</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/double-diffusive-instability/" target="_blank">#doubleDiffusiveInstability</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/flow-visualization/" target="_blank">#flowVisualization</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/fluid-dynamics/" target="_blank">#fluidDynamics</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/oceanography/" target="_blank">#oceanography</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/physics/" target="_blank">#physics</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/science/" target="_blank">#science</a>

Nicole SharpSalt Affects Particle Spreading <a class="" href="https://fyfluiddynamics.com/wp-content/uploads/salt_mp1.png" rel="nofollow noopener" target="_blank"></a> <a class="" href="https://fyfluiddynamics.com/wp-content/uploads/salt_mp2-1.png" rel="nofollow noopener" target="_blank"></a> <a class="" href="https://fyfluiddynamics.com/wp-content/uploads/salt_mp3-1.png" rel="nofollow noopener" target="_blank"></a> Microplastics are proliferating in our oceans (and everywhere else). This video takes a look at how salt and salinity gradients could affect the way plastics move. The researchers begin with a liquid bath sandwiched between a bed of magnets and electrodes. Using Lorentz forcing, they create an essentially 2D flow field that is ordered or chaotic, depending on the magnets’ configuration. Although it’s driven very differently, the flow field resembles the way the upper layer of the ocean moves and mixes. The researchers then introduce colloids (particles that act as an analog for microplastics) and a bit of salt. Depending on the salinity gradient in the bath, the colloids can be attracted to one another or repelled. As the team shows, the resulting spread of colloids depends strongly on these salinity conditions, suggesting that microplastics, too, could see stronger dispersion or trapping depending on salinity changes. (Video and image credit: <a href="https://doi.org/10.1103/APS.DFD.2024.GFM.V2641007" rel="nofollow noopener" target="_blank">M. Alipour et al.</a>)<a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/2024gofm/" target="_blank">#2024gofm</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/electrohydrodynamics/" target="_blank">#electrohydrodynamics</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/flow-visualization/" target="_blank">#flowVisualization</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/fluid-dynamics/" target="_blank">#fluidDynamics</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/geophysics/" target="_blank">#geophysics</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/magnetic-field/" target="_blank">#magneticField</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/physics/" target="_blank">#physics</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/plastic-pollution/" target="_blank">#plasticPollution</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/science/" target="_blank">#science</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/turbulence/" target="_blank">#turbulence</a>

Nicole SharpA Drop’s Shape EffectsFalling raindrops get distorted by the air rushing past them, ultimately breaking large droplets into many smaller ones. This research poster shows how variable this process is by showing two different raindrops, both of the same 8-mm initial diameter. On the left, the drop is prolate — longer than it is wide — and on the right, the drop is oblate — wider than it is long. Moving from bottom to top, we see a series of snapshots of each drop’s shape as it deforms and, eventually, breaks into smaller drops. The overall process is similar for each: the drop flattens, dimples, and then inflates like a sail, with part of the drop thinning into a sheet and ultimately breaking into smaller droplets. Yet, each drop’s specific details are entirely different. (Image credit: <a href="https://doi.org/10.1103/APS.DFD.2024.GFM.P2691171" rel="nofollow noopener" target="_blank">S. Dighe et al.</a>)<a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/2024gofm/" target="_blank">#2024gofm</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/bag/" target="_blank">#bag</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/droplet-breakup/" target="_blank">#dropletBreakup</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/droplets/" target="_blank">#droplets</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/flow-visualization/" target="_blank">#flowVisualization</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/fluid-dynamics/" target="_blank">#fluidDynamics</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/physics/" target="_blank">#physics</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/raindrops/" target="_blank">#raindrops</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/science/" target="_blank">#science</a>

Nicole SharpKolmogorov TurbulenceTurbulent flows are ubiquitous, but they’re also mindbogglingly complex: ever-changing in both time and space across length scales both large and small. To try to unravel this complexity, scientists use simplified model problems. One such simplification is <a href="https://file.scirp.org/pdf/JAMP_2018111610542834.pdf" rel="nofollow noopener" target="_blank">Kolmogorov flow</a>: an imaginary flow where the fluid is forced back and forth sinusoidally. This large-scale forcing puts energy into the flow that cascades down to smaller length scales through the <a href="https://en.wikipedia.org/wiki/Energy_cascade" rel="nofollow noopener" target="_blank">turbulent energy cascade</a>. Here, researchers depict a numerical simulation of a turbulent Kolmogorov flow. The colors represent the flow’s vorticity field. Notice how your eye can pick out both tiny eddies and larger clusters in the flow; those patterns reflect the multi-scale nature of turbulence. (Image credit: <a href="https://doi.org/10.1103/APS.DFD.2024.GFM.P2579354" rel="nofollow noopener" target="_blank">C. Amores and M. Graham</a>)<a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/2024gofm/" target="_blank">#2024gofm</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/flow-visualization/" target="_blank">#flowVisualization</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/fluid-dynamics/" target="_blank">#fluidDynamics</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/kolmogorov/" target="_blank">#Kolmogorov</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/numerical-simulation/" target="_blank">#numericalSimulation</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/physics/" target="_blank">#physics</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/science/" target="_blank">#science</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/turbulence/" target="_blank">#turbulence</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/turbulent-energy-cascade/" target="_blank">#turbulentEnergyCascade</a>

Nicole SharpVisualizing Unstable Flames <a class="" href="https://fyfluiddynamics.com/wp-content/uploads/thermo_instab1.gif" rel="nofollow noopener" target="_blank"></a> <a class="" href="https://fyfluiddynamics.com/wp-content/uploads/thermo_instab2.gif" rel="nofollow noopener" target="_blank"></a> <a class="" href="https://fyfluiddynamics.com/wp-content/uploads/thermo_instab3.png" rel="nofollow noopener" target="_blank"></a> Inside a combustion chamber, temperature fluctuations can cause sound waves that also disrupt the flow, in turn. This is called a thermoacoustic instability. In this video, researchers explore this process by watching how flames move down a tube. The flame fronts begin in an even curve that flattens out and then develops waves like those on a vibrating pool. Those waves grow bigger and bigger until the flame goes completely turbulent. Visually, it’s mesmerizing. Mathematically, it’s a lovely example of <a href="https://en.wikipedia.org/wiki/Parametric_oscillator" rel="nofollow noopener" target="_blank">parametric resonance</a>, where the flame’s instability is fed by system’s natural harmonics. (Video and image credit: <a href="https://doi.org/10.1103/APS.DFD.2024.GFM.V2561866" rel="nofollow noopener" target="_blank">J. Delfin et al.</a>; research credit: J. Delfin et al. <a href="https://doi.org/10.1016/j.fuel.2024.132344" rel="nofollow noopener" target="_blank">1</a>, <a href="https://doi.org/10.1016/j.proci.2024.105322" rel="nofollow noopener" target="_blank">2</a>)<a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/2024gofm/" target="_blank">#2024gofm</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/combustion/" target="_blank">#combustion</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/combustion-instability/" target="_blank">#combustionInstability</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/flame/" target="_blank">#flame</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/flow-visualization/" target="_blank">#flowVisualization</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/fluid-dynamics/" target="_blank">#fluidDynamics</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/instability/" target="_blank">#instability</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/parametric-resonance/" target="_blank">#parametricResonance</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/physics/" target="_blank">#physics</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/resonance/" target="_blank">#resonance</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/science/" target="_blank">#science</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/thermoacoustic-instability/" target="_blank">#thermoacousticInstability</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/turbulence/" target="_blank">#turbulence</a>

Nicole Sharp“Kirigami Sun”<a href="https://en.wikipedia.org/wiki/Kirigami" rel="nofollow noopener" target="_blank">Kirigami</a> is a variation of origami in which paper can be cut as well as folded. Here, researchers look at flow through a cut kirigami sheet and how that flow changes with the cuts’ length. In the top central image, white lines mark the paper boundaries. As the cut gaps get larger, flow through them transitions from a continuous jet to swirling vortex shedding. Along the bottom, we see similar patterns emerge in the wake of uniformly-cut sheets, too. On the right, the flow comes through in jets; moving leftward, it transitions to an unsteady vortex shedding flow. (Image credit: <a href="https://doi.org/10.1103/APS.DFD.2024.GFM.P2684224" rel="nofollow noopener" target="_blank">D. Caraeni and Y. Modarres-Sadeghi</a>)<a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/2024gofm/" target="_blank">#2024gofm</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/flow-visualization/" target="_blank">#flowVisualization</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/fluid-dynamics/" target="_blank">#fluidDynamics</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/jets/" target="_blank">#jets</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/physics/" target="_blank">#physics</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/science/" target="_blank">#science</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/vortex-shedding/" target="_blank">#vortexShedding</a>

Nicole SharpGalloping Bubbles <a class="" href="https://fyfluiddynamics.com/wp-content/uploads/galbub1.png" rel="nofollow noopener" target="_blank"></a> <a class="" href="https://fyfluiddynamics.com/wp-content/uploads/galbub2.gif" rel="nofollow noopener" target="_blank"></a> <a class="" href="https://fyfluiddynamics.com/wp-content/uploads/galbub3.gif" rel="nofollow noopener" target="_blank"></a> A buoyant bubble rises until it’s stopped by a wall. What happens, this video asks, if that wall vibrates up and down? If the vibration is large enough, the bubble loses its symmetry and starts to gallop along the wall. Using numerical simulations, the team determined the flow around the bubble. They also demonstrate several possible applications for this behavior: sorting bubbles by size, traversing mazes, and cleaning a surface. (Video and image credit: <a href="https://doi.org/10.1103/APS.DFD.2024.GFM.V2684816" rel="nofollow noopener" target="_blank">J. Guan et al.</a>)<a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/2024gofm/" target="_blank">#2024gofm</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/bubbles/" target="_blank">#bubbles</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/experimental-fluid-dynamics/" target="_blank">#experimentalFluidDynamics</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/fluid-dynamics/" target="_blank">#fluidDynamics</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/numerical-simulation/" target="_blank">#numericalSimulation</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/physics/" target="_blank">#physics</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/science/" target="_blank">#science</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/vibration/" target="_blank">#vibration</a>

Nicole SharpInstabilities in CompetitionWhen two liquid jets collide, they form a thin liquid sheet with a thicker rim. That rim breaks into threads and then droplets, forming a well-known fishbone pattern as the Plateau-Rayleigh instability breaks up the flow. This poster shows a twist on that set-up: here, the two colliding jets vary slightly in their velocities. That variability adds a second instability to the system, visible as the wavy pattern on the central liquid sheet. The sheet’s rim still breaks apart in the usual fishbone pattern, but the growing waves in the center of the sheet eventually that structure apart as well. (Image credit: <a href="https://doi.org/10.1103/APS.DFD.2024.GFM.P2692828" rel="nofollow noopener" target="_blank">S. Dighe et al.</a>)<a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/2024gofm/" target="_blank">#2024gofm</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/fishbone/" target="_blank">#fishbone</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/fluid-dynamics/" target="_blank">#fluidDynamics</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/fluids-as-art/" target="_blank">#fluidsAsArt</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/instability/" target="_blank">#instability</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/jet-collision/" target="_blank">#jetCollision</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/physics/" target="_blank">#physics</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/plateau-rayleigh-instability/" target="_blank">#PlateauRayleighInstability</a> <a rel="nofollow noopener" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/science/" target="_blank">#science</a>

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