Originally Posted by Jeep2Xfire
Bernoulli's Principle. For those who don't know, Google Daniel Bernoulli, Swiss physicist circa 18th century I think? Venturi effect. This is how fuel is atomized in a carb, pitot tube sounds a stall warning in a Cessna (or other GA aircraft), or the reason you can walk down a street with a light breeze on you and then you pass by the opening of an alley and almost get blown over. Neat stuff.
As the velocity of a fluid increases (in this case air; fluid- matter that takes the shape of ts container) it's pressure decreases and vice versa.
Thought about mentioning Bernoulli but didn't want to try to spell his name.
One minor clarification: a pitot tube lets in ram air and compares it against static air to give an air speed indication. A stall warning device is what activates a stall warning indicator in GA (general aviation - Cessnas, Pipers and Beechcrafts).
As for alleyway breezes, I've been told that a contractor who wants to put up a building in Chicago has to do a study on the effects the building will have on the local winds. There's a reason Chicago is known as the windy city.