They develop strong vortices and cause air to flow

This preview shows page 155 - 176 out of 176 pages.

They develop strong vortices, and cause air to flow upward and inward around each vortex generator.* this action has the effect of drawing high energy air from outside the boundary layer into the slow moving air near the aircraft skin.> Drag reduction is achieved. Fig 4-7. Reduce shock induced drag.
Background image
Background image
Background image
Background image
The purpose of these modifications is to create vortices in a controlled and predictable manner. Vortices are often undesirable because they produce drag, but the vortices these devices create are beneficial since they delay wing stall. Stall occurs when a wing reaches a high enough angle of attack that the airflow separates from its surface.
Strakesis the official name, but they are really vortex generators
Large vortex generator located on a Boeing 737 engine nacelle
Vortex generators on the engine nacelle of an Airbus A319
Large vortex generator plates visible on the engine cowlings of a C-17
Vortex generator-strake
Vortex Generators- Notice the 10 small vortex generators above the radome. These reduce the cockpit noise from the windshield by 3dB.
Background image
Vortex Generator
Background image
Background image
F-16 Vortex generatorControlled vortex lift generated by forebody strakes on the General Dynamics F-16
Leading edge extensions (LERXS) F-18
LERXs generate vortices and add lift ahead of the center of gravity
Planforms for High Speed FlightThe ideal shape for a supersonic airfoil, is a biconvex design.At Mach numbers wings need to be very thin, wing is then not strong and has poor lift at slow speeds.Sweptback increases critical mach but presents stability issues.At Supersonic speeds the advantage of sweptback wing decreases at Mach 2, the straight wing is superior.Reduce the aspect ratio.(Concorde 1.7)

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture