
MIT solves 100-year-old engineering problem - Anon84
http://esciencenews.com/articles/2008/09/25/mit.solves.100.year.old.engineering.problem
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marvin
This seems to be related to laminary flow separation
<http://en.wikipedia.org/wiki/Flow_separation>. The news article doesn't give
too many details. Under certain aerodynamic conditions, the airflow separates
from the barrier it is flowing around, forming "bubbles" of vacuum that
increase drag considerably.

From what I know of aerodynamics, improvements in when flow separation occurs
will not have much impact on fuel consumption. Flow separation only causes
increased drag at low speeds. At higher speeds, the phenomenon doesn't occur -
the problem at higher speeds is that the airflow remains attached to the
surface, but flows turbulently instead of smoothly. The ideal wing has smooth
(laminary) flow over the entire surface, without any flow separation. This has
thus far been unachievable in practice. For all I know, this new theory might
also address this problem, but it hardly seems like a revolution is in the
works. We have a decent understanding of these phenomena already. It's more
related to statistics than engineering.

The point with the rugged surface of golf balls (or turbulators on airplanes)
is to force the laminary air flow to become turbulent. Flow separation only
occurs when the airflow is smooth. So we accept an increase in drag to prevent
an even bigger increase in drag.

Perhaps we could improve the aerodynamics of cars (cars move at low speeds),
but I doubt that flow separation is the main barrier to better fuel efficiency
here.

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rw
"MIT" doesn't solve anything. Anthropomorphizing institutions is bad bad bad!

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pmjordan
Yeah, they don't like that!

