Nicole Sharp<p><strong>Visualizing Unstable Flames</strong></p> <p><a class="" href="https://fyfluiddynamics.com/wp-content/uploads/thermo_instab1.gif" rel="nofollow noopener noreferrer" target="_blank"></a></p> <p><a class="" href="https://fyfluiddynamics.com/wp-content/uploads/thermo_instab2.gif" rel="nofollow noopener noreferrer" target="_blank"></a></p> <p><a class="" href="https://fyfluiddynamics.com/wp-content/uploads/thermo_instab3.png" rel="nofollow noopener noreferrer" target="_blank"></a></p> <p></p> <p>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 noreferrer" 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 noreferrer" 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 noreferrer" target="_blank">1</a>, <a href="https://doi.org/10.1016/j.proci.2024.105322" rel="nofollow noopener noreferrer" target="_blank">2</a>)</p><p><a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/2024gofm/" target="_blank">#2024gofm</a> <a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/combustion/" target="_blank">#combustion</a> <a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/combustion-instability/" target="_blank">#combustionInstability</a> <a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/flame/" target="_blank">#flame</a> <a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/flow-visualization/" target="_blank">#flowVisualization</a> <a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/fluid-dynamics/" target="_blank">#fluidDynamics</a> <a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/instability/" target="_blank">#instability</a> <a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/parametric-resonance/" target="_blank">#parametricResonance</a> <a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/physics/" target="_blank">#physics</a> <a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/resonance/" target="_blank">#resonance</a> <a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/science/" target="_blank">#science</a> <a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/thermoacoustic-instability/" target="_blank">#thermoacousticInstability</a> <a rel="nofollow noopener noreferrer" class="hashtag u-tag u-category" href="https://fyfluiddynamics.com/tagged/turbulence/" target="_blank">#turbulence</a></p>