HampusA wrote:How much differs subsonic vs sonic flows?
Well, flyn is correct, but I would like to add that the main difference I see is that at subsonic the air has "time" to move away from the wing or object, while at supersonic it hasn't.
Picture yourself as an atom, floating in the air. If you were to be "touched" by a wing moving at subsonic speeds, the waves created in the air by the leading edge of the wing would reach you before the wing does. So, you would move away from the edge of the wing and "follow" its contour.
If this wing moves at supersonic speeds you wouldn't receive any "warning" to move away before the wing or object hits you.
This is what creates a shock wave in front of objects moving at supersonic speeds: it is the result of the atoms of air being pushed away "directly" by the object, instead of being pushed around by the surrounding molecules, as they "usually" do.
At least that's how I've seen this business all my life.
Thanks, a very nice explanation.
The freak thing i was just listening to "the good. the bad % the ugly" soundtrack So for every word it just sucked me in even more