Questions tagged [fluid-dynamics]

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32
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3answers
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Why does Coriolis determine the rotation direction of a cyclone but not my drain?

It is a common misconception that Coriolis is responsible for the direction the water swirls down a toilet, tub or sink drain. E.g. does a toilet flush the other way in the southern hemisphere? (If ...
4
votes
1answer
150 views

Why would geostrophic theory be invoked in the tropics with regards to the MJO?

In this paper reviewing the Madden-Julian Oscillation, frequently geostrophic theory (or approximately geostrophic) is often invoked. However, for geostrophic theory to be invoked, $$Ro=\frac{U}{f_0L}&...
2
votes
1answer
58 views

At what point are water droplets too small to make a rainbow?

This question asks How to tell if fog is made out of water droplets or ice crystals? I know that ice fog makes a rainbow where fog does not. Ice crystals aside: How does the water droplet size ...