FROM BOMBER TO BOUNDARY LAYER

摘要

The Northrop X-21 - twenty-first in a long series of dedicated experimental 'X-planes' - was designed and built to explore the intricacies of laminar flow control (LFC). This is a subset of boundary layer control (BLC) technology employed to enhance aircraft performance or solve aerodynamic problems. BLC typically involves blowing compressed air out thin span-wise slots along a portion of the wing upper surface to reenergize the boundary layer and keep it attached for more of the chord length. By contrast, LFC generally involves sucking the boundary layer off of the wing to meet the same aerodynamic goal.