Applications and developments of a kind of vortex control device, the nacelle strake, are first reviewed. Underlying flow control mechanisms are then demonstrated through CFD simulations. Once the nacelle strake is properly designed and installed, strong vortices shed from the strake can produce upwashes and reenergize the separation-sensitive boundary layer on the upper wing behind the nacelle. The stall characteristics are improved by lowering the effective angle of attack and delaying premature bursts of the pylon vortex.