In the midst of hell, there is fire. Who would’ve guessed?

So amidst the recent hell from school, (2 all-nighters in a row a couple weeks ago; a new record, but that’s besides the point), and the same setup of lab reports and midterms coming up next week, I am taking my leisure in napping, slacking off, and just generally basking in the calm before the storm. The real storm is exam time, when 12.5 hours of examination are worth 50-60% of my semester’s mark. Fun fun fun.

So about 3 weeks ago, I skipped a couple of lectures to go to a series of Capstone lectures by several students. For those of you not well acquainted with the U of T engineering system, Capstone is basically a half -year thesis course, seen more in the engineering and law sectors. This gives people a big project, but small enough to diversify. Anyways, each pair had to give a 20 minute presentation on their topic while being graded. One of particular which I found rather interesting was on the topic of fire tornadoes. Come on, with a topic like fire tornadoes, you can’t go wrong.

Here’s a video of the highlight of the presentation. Kudos to Song for taping the thing. Albeit slightly unclear, you can see “fire grooves” when spun, which is essentially the spiralling tornado. What strikes me as amazing is the fact that you essentially have fire, virtually impossible to model given its chaos, apply some controlled energy to the system, and suddenly you have a very simple way of modelling the properties of this fire. In fact, the fire is governed only on 2 concepts, Kelvin’s circulation theorem and Bernoulli’s equation. Kelvin’s circulation theorem says that if you have a fluid that is incompressible and a low viscosity (not like molasses; water and air are good examples of such fluids) then there is a conservation of angular momentum. Imagine the skater spinning slow with its arms out, and then faster when they pull their arms in, except it is something like water in a container rotating around the central axis. The speeds will be faster near the edges, and slower near the axis (centre).  Bernoulli’s equation says that if you have a fluid moving from a lower velocity to a higher one the pressure will decrease, maintaining a conservation of momentum.  The higher speed at which the outer column rotates at, the narrower and more spiralling the fire tornado will be. The difference in pressure and velocity based on these laws make air flow in such a way that the fire that requires the oxygen to burn moves like a tornado. This is another video I found on youtube, except much cornier.

I guess in the midst of my stress and despising of the work I forgot the beauty of physics and why I went into this in the first place. It is for this very reason, at which everything can be explained with simple equations and concepts, and in the end all that it’s doing is it’s confirming your intuition. That’s the beauty of the simplicity of math, however complicated it might be.

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