Why does static press < when dyanmic press >?
Ok, for me, this one's a bit like gravity. I know it happens, but I don't understand why.
The question is, why does a reduction in dynamic pressure result in an increase in static pressure, and vice versa?
We've all seen the tautliners on the motorway with their curtains sucked inwards (ooooh err!), this being due a partial vacuum forming inside the trailer because the air is being drawn to the outside, because that's where there's high dynamic pressure, i.e. relative wind, i.e. lower static pressure.
Same principle explains why, in general, the 'cabin altitude' of an unpressurised aircraft is usually slightly higher than its true altitude. Due to relative motion, the air is moving much faster (relatively) outside, giving a lower static pressure, therefore some air from the cockpit/cabin will be drawn outside.
I'm understanding the 'why', just not the 'how'!
Any helpers?