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-...

Figure 2 has labels cut off, but there seems to be 6 engines around the craft, forcing air to 6 points (note where it is labeled "engine access panel"): http://www.extremetech.com/wp-content/uploads/2012/10/Fig-2-...

The article that explains the effect: http://www.pdf-archive.com/2011/09/07/applications-of-the-co...