Nicole Sharp
Nicole Sharp

Celebrating the physics of all that flows with Nicole Sharp, Ph.D.

4,165 posts
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  • Martian Landslides

    Sometimes there are advantages to studying planetary physics beyond Earth. Mars does not have plate tectonics, vegetation, or the level of erosion we do, allowing geological features like those left behind by landslides to persist undisturbed for millions of years. And, thanks to a suite of orbiters, we’ve mapped most of Mars at a resolution…

  • Drying Out

    Look closely at old paintings, and you’ll notice arrays of tiny, straight cracks that form as the paint dried. This sort of pattern formation during drying is not unusual. Here we see the patterns formed when a thin layer of hydrogel sandwiched between two glass plates dries. As the water evaporates, stress builds at the…

  • Robotic Research Facilities

    One of the major challenges in fluid dynamics is the size of the parameter spaces we have to explore. Because many problems in fluid dynamics are non-linear, making small changes in the initial set-up can result in large differences in the results. Consider, for example, a simple cylinder towed through a water tank. As the…

  • Envisioning Chemical Patterns

    One of the most beautiful chemical reactions is the Belousov–Zhabotinsky reaction, and it’s the subject of the latest video from Beauty of Science. Known colloquially as the BZ reaction, it begins as growing spots of color that turn into rings and chaotic spirals as the chemical reaction progresses. Mathematically, the BZ reaction is a type…

  • Falling Drops and Forming Stalagmites

    The vast stalactites and stalagmites found in caves take millennia to form. Mineral-rich water seeps down the icicle-like stalactites and then drips onto stalagmites below, each drop depositing a little more calcite onto the growing rock. By observing this dripping action first-hand, researchers found that most falling drops create a splash that’s much smaller than…

  • An Introduction to the Reynolds Number

    For those who’d like an overview of the mathematics involved in fluid dynamics, Numberphile has a lovely introduction, given by our friend Tom Crawford. The governing equations in fluid dynamics, the Navier-Stokes equations, are quite complicated, but that’s just been inspiration for scientists and mathematicians to come up with clever ways to simplify them. And,…

  • Flow on Commercial Wings

    Even in an era of supercomputers, there is a place for quick and dirty methods of flow visualization. Here we see a model of a swept wing like those seen on many commercial airliners. It was painted with a layer of fluorescent oil, then placed in a wind tunnel and subjected to flow. As air blows…

  • CU Flow Vis 2019

    I love when science and art come together, which is why I’ve long been a fan of the Flow Vis course at CU Boulder. Some of my earliest posts on FYFD date from previous editions of the course. Here are a few of my favorite images from the Fall 2019 class, from the top:  Ferrofluid and India ink merge in this colorful…

  • Inside the Earth’s Mantle

    Plate tectonics is a relatively young scientific theory, only gaining traction among geologists in the late 60s and early 70s. One key tenet of the theory is subduction where plates meet and one is forced down into the mantle, like in this illustration of the subduction zone near Japan. In early incarnations of the theory what happens to…

  • “Magic Fluids”

    In his short film, “Magic Fluids,” Roman De Giuli uses cyan, magenta, and yellow paints to generate a rainbow of macro colors. All the fluid motion you see is a practical effect, painstakingly created by layering paints and flow mediums of different densities. Like in Siqueiros’ “accidental painting” technique, the less dense paints will eventually rise through the…