Shock Waves on Supercritical Airfoils

[ccaulder]

I've got a question coming up on a test concerning shock waves and super critical airfoils. I've been t a bunch of website but i still don't understand completly. so anyways,

1. How/why are shock waves created on a supercritical airfoil flying above the critical mach number but below supersonic speed.


2. where along the airfoil does the shock wave form, does it have anything to do with the point of lowest pressure or the point of maximum thickness of the airfoil?

thanks a lot

 

[rb1957]

1) the local mach number is supersonic ... this was a problem with WW2 fighter wings.

2) i think it is related to the pressure distribution, but whether it is lowest, highest, or steepest gradient (which would imply highest velocity) i'm not sure.

i am surprised that you couldn't get this off the web (wiki?)

 

[gontek]

Review you Prandtl-Meyer and Bernouli equations expressed in Mach numbers. Wikipedia has a pretty decent explanation actually.

http://en.wikipedia.org/wiki/Mach_number