air show jets
Thread Starter
Joined: Mar 2001
Posts: 223
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From: Toronto, Ont, Canada
air show jets
Yesterday was the first of 3 days for the Toronto Air show.
Pefect weather for it, 20deg C / severe clear and sunny.
Watching the mil jets, during the high speed / high G manouvers, a "white layer" was visible on the wings.
Is this a "shock wave" caused by supersonic / trans sonic flow over the wings ? ... and the prelude to a sonic boom ?
Mike
[ 02 September 2001: Message edited by: mstram ]
Pefect weather for it, 20deg C / severe clear and sunny.
Watching the mil jets, during the high speed / high G manouvers, a "white layer" was visible on the wings.
Is this a "shock wave" caused by supersonic / trans sonic flow over the wings ? ... and the prelude to a sonic boom ?
Mike
[ 02 September 2001: Message edited by: mstram ]
Joined: Dec 1999
Posts: 27
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From: Approaching DANDI FL240
Could be some new secret camouflage system... 
...but more likely is just the low pressure over the wings causing condensation of the airs moisture. You can see the same thing happening at / near the wing tips and leading edge extensions along the body (e.g. F/A 18). When the aircraft is pulling high G, the AoA is pretty high, leading to greater pressure difference between upper and lower wing surface (or lower and upper if inverted).
... I, eer, think...
...but more likely is just the low pressure over the wings causing condensation of the airs moisture. You can see the same thing happening at / near the wing tips and leading edge extensions along the body (e.g. F/A 18). When the aircraft is pulling high G, the AoA is pretty high, leading to greater pressure difference between upper and lower wing surface (or lower and upper if inverted
).... I, eer, think...
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Joined: Feb 2000
Aviation Qualifications: CPL
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From: UK
Ivan is quite correct, it's properly called "Condensation Shock", back in the mists of time (the 1950s anyway) before Schlieren photography was invented, it was used in transonic and supersonic wind tunnels for shock wave visualisation.
I can't find the equations to hand, but it occurs at a given combination of *local* Mach number, relative humidity, and temperature.
G
I can't find the equations to hand, but it occurs at a given combination of *local* Mach number, relative humidity, and temperature.
G
