so from what I understand, the air bends around a surface the way water sticks to the side of a teapot. The nozzle design has a "step", a little cutout at the top of the curve closest to where the air is exiting from. This little step causes a small vortex, or eddy, like in a river. The vortex causes an area of lower pressure which bends the stream of air. You can clearly see the exhaust nozzles on "fig-1" of the declassified documents:
http://www.extremetech.com/wp-content/uploads/2012/10/Fig-1-...