Originally Posted by T.O.E Dream
I know that low pressure air is created when air moves fast, but what other ways are low pressure air made?
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Depends why the air is moving fast. Take the simple case of a propeller, as the air passes through the virtual disk formed by the rotating prop it's speed isn't changed much, but the pressure is. The air ahead of the prop accelerates into the low pressure zone in front of the prop, then the pressure is increased, and the air continues to accelerate as it's pressure is reduced back to ambient.
When solids interact with fluids or gasses, both pressure and speed can be changed by that interaction. The exhaust from a jet engine is both high pressure and high speed.
For the fluid or gas flow outside of the region of interaction with a solid, that fluid or gas accelerate from higher pressure zones to lower pressure zones, and the relationship between the change in pressure versus change in speed can be converted into a relationship between static pressure and speed, and this relationship can be approximated by Bernoulli equation (Bernoulli doesn't take turbulent factors into account).
There are man made "flying saucer" type aircraft that use a set of propellers (vertical axis) located in holes around the aircraft. One of these was demoed at the 1984 Los Angeles Olympics.
