Quote:
Originally Posted by RobertSmalls
Similitude (model) - Wikipedia, the free encyclopedia
You can get a dime to float in a glass of water, but a manhole cover the shape of a dime can not be made to float. Surface forces do not scale the way you might think.
If you test a scale model in a wind tunnel without achieving similitude, you will get different results.
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If the manhole cover's size and weight were both scaled accordingly to the dime, I'm pretty certain it
would float.
The problem with the comparison is that while a manhole cover might be 1,000x the volume, it's probably 10,000x the
mass, making it less buoyant.
I do agree about the wind tunnel comparison, though. The changes in cd won't be scalar as the size of the object (and the size of features related to the object) increases.
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