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Old 12-05-2012, 10:30 AM   #4 (permalink)
Joeggernaut
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Quote:
Originally Posted by minimac View Post
I'm really late to coming around to these streamlining discussions, and I understand a lot of work has been done by a lot of people, but why does this shape have to be accepted as being best? Airplanes go through the air well and are not that shape. Rockets are shot into space and are not that shape. Land speed vehicles are usually not that shape, nor are missiles. I think that would prove that the best shape for cutting air would be a pointy cylinder. What am I missing?
Fluid dynamics is probably the least understood science of them all. There are a few laws (mostly all related to conservation of energy) but there is not one law that can lead to the optimal solution across all scenarios. The main reason being is that fluid (including air) behaves in different states and applications.

Super-sonic jets don't utilize the tear drop because there are different applications such as how sound comes in to play, etc.

When car manufactures make cars they don't apply one law to govern the most aerodynamic shape since there isn't one. They have to use computers to run complicated models to come up with their designs. It is a iterative approach which means the next optimal output depends on the input from the first process. It just happens to be that the tear drop is the most optimal solution for the applications a vehicle will see.

In space there is not fluid so the spacecraft can be any shape it wants to be and still have the same efficiency as another. It is only when it enters the atmosphere does fluid dynamics come into affect. That is the why the space shuttle is not very efficient flyer during return flights but it was design for storage and heat displacement instead.

There are many papers/articles and people can go on and on about aerodynamics but it all boils down to that there isn't one law that encompasses all of aerodynamics.
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