So perhaps you have heard of Mr. Prandtl, giant among men in the field of fluid mechanics. Apparently back in the day, he had formulated his theories about laminar (laminar = not turbulent) flow around a cylinder and he had a bunch of equations that seemed extremely mathematically sound. This was before anyone even thought about turbulent flow, you see.

Pleased with his results, he took on a graduate student named Munch. Munch's project was to build a water tunnel and a cylinder, and then to take pictures of the flow going around it in order to prove experimentally his advisor's theoretical results.

So Munch built the flume, and he ran water through it, and sure enough, he found that the flow was completely different than his advisor had predicted. Like, COMPLETELY different. He took his results to his advisor, who, like all advisors in such situations, decided that his calculations were still right and that Munch had built the flume wrong. He told him to go back and rebuild it and make sure that the surface of the cylinder was extremely smooth, and the walls of the tunnel were extremely smooth, thus ensuring that the boundary conditions would match what Prandtl had proscribed.

For two years, Munch worked to make the walls of the tunnel smooth and the cylinder smooth, and to make the experiment exactly match Prandtl's specifications. But each time he ran the experiment he saw the same kind of flow and the cylinder would start vibrating when he turned up the velocity too high.

By this time, his office mate, VonKarman, had come back from the War. (Apparently he'd been in the Austrian Army or something). He resumed his studies and his place in Munch's office, and when he saw the experiments that Munch was running, he surmised that in fact the experiments were totally correct, and Prandtl was wrong (assumedly Prandtl was not VonKarman's advisor). So he went and made a theoretical model of what he thought was happening... that is- TURBULENCE! He decided that instead of sticking to the side of the cylinder as the flow bent around it, it would become separated from the cylinder, causing flow separation and the creation of alternating vorticies, which caused the cylinder to start vibrating. (Just like the singing islands or telephone wires that I've talked about in the past!)

So VonKarman published a paper about this, and now we have VonKarman vorticies, and we have a Prandtl Number, and do we have anything about Munch?

Perhaps only a scream of utter despair.

Moral of the story?

Don't go to graduate school.

:( Why is all of this over my head?


BTW, What do you see happening to the America, and the rest of the world, when we run out of fossil fuels? DO you think we'd be able to use fusion power ( yay ) or nuclear ( boo ) power.. or something..

What do you think?
» Dilated on 2008-04-03 10:18:39

Lol, or don't be afraid to question your advisor!

Think, if Munch has just been confident enough to say to himself, "You know what, I DID do this right!" then he could have done the experiments, made the formulas and has it called "Munch's Vorteicies" (or maybe... Munchticies) changing the course of history as we know it!

Or maybe I don't know anything about grad school...
» jinyu on 2008-04-03 10:34:51

I don't take crap from my teachers.
If they're wrong, I shall tell them. HAI-YAH!

I love the feeling of singing sand. The finer, the better.
» middaymoon on 2008-04-03 11:27:51

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