Originally Posted by Crow hunter
It sounds like a method of boundary layer control used on aircraft. Some airplanes will have small pores in the skin in certain areas where small amounts of bleed air from the engines are pumped through to break up the boundary layer, thus reducing drag.

The boundary layer on an aircraft (or sub/ship hull) is the area right next the skin where at a microscopic level the air or water kind of "sticks" to the skin. If you can

break up that "stickiness" then you can cut down on a lot of the drag so you can go faster with less power.

https://en.wikipedia.org/wiki/Boundary_layer


The F-4 N's and J's had both leading edge and trailing edge BLC on the leading edge slats and the flaps to energize the boundary layer to move it faster. It allowed us to fly slower w/o stalling. It also created the distinctive howling noise you'd hear from a jet in the landing pattern.


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