"We're There to Keep You in the Air"
VORTEX GENERATORS
Improve your aircraft's safety envelope
Although the term Vortex Generator is most commonly used to describe the small aluminum tabs attached to the top of the wings, vortex generators actually come in many shapes and sizes. The VG's we promtoe use four different designs of vortex generators to control or to modify airflow. Each design addresses a particular kind of problem at different locations on the aircraft.
Generally, but not always, vortex generators are set in angled pairs down the full span of the wings. A typical vortex generator kit will have approximately 20 pairs of vortex generators attached to each wing.
The vortex generators are designed to only function when an aircraft is at a high angle of attack. In level flight they are buried in the boundary layer and have no effect on the airflow. As the nose of the aircraft is pulled up and the angle of attack increases, the vortex generators begin to interact with the free stream air that is passing over the wings. Miniature vortices are created which introduce additional energy into the airflow. This forces the airflow to remain attached to a higher than normal angle of attack before the stall occurs.
An additional benefit of the vortex generators is the improved control response that comes as a direct result of the re-energized airflow over the aileron. The size of the vortex generators is critical to how effective it will be on a particular aircraft. The size directly correlates with the wing cord length. The longer the chord, the larger the vortex generator needs to be. In the wing walk areas we use solid aluminum, triangular shaped vortex generators that can be stepped on without damaging them.
Fuselage Strakes are formed pieces of aluminum or fiberglass that attach to the fuselage near the wing root. The wing root is commonly an area where the airflow is severely disrupted due to the not so aerodynamic nature of the nose and wing-fuselage intersection. The strakes are essentially just large vortex generators that are used to clean up, or smooth the airflow at the wing root. Smoother airflow translates to less drag and reduced stall speeds. An additional benefit of the fuselage strakes is that they provide added energy to the airflow over the tail surfaces of the aircraft.
Delta Wings are curved, delta shaped fibreglass parts that are mounted at the leading edge of the wing. They are designed to shed two large counter-rotating vortices. These vortices are very powerful and act as invisible barriers or stall fences that stop the outward propagation of the stall. A fixed stall fence works to a point; but once the angle of attack increases enough the stall will simply “jump over” the fence. The vortices produced by the delta wings actually increase in size as the aircraft’s speed decreases. These self-adjusting “vortex walls” are large and powerful enough that they will not allow the stall to continue outward.
Both wind tunnel and in-flight tests have confirmed that the use of vortices to control stall propagation is significantly more effective than traditional fixed stall fences. Most general aviation aircraft are designed so that the stall will begin at the wing root and progress outward toward the wingtip. However, not all aircraft wings are optimally designed. Stall characteristics can vary tremendously. Often what will happen is the entire wing will stall at the same time, which results in an almost instantaneous loss of control. Obviously this is a very undesirable condition for both aircraft and pilot.
By strategically placing delta wings along the span of the wing we are able to control the propagation of the stall regardless of where it may begin. By not allowing the stall to reach the outboard section of the wings, the pilot maintains aileron control even while the rest of the wing is stalled. A vortex generator kit without delta wings will reduce stall speeds and improve handling to the point of the stall, but becomes ineffective once the stall occurs.
Through the use of various combinations of vortex generators, strakes, and delta wings our ag series vortex generator systems increase performance and add safety margins far beyond those of any other vortex generator kits on the market.
Kits are currently available for the following ag models:
Air Tractor 300, 400, 500 series
Cessna 188B, A188B, T188C
Piper Brave 285, 300, 375
Thrush, Turbine and Piston
Dromader (all models)
Weatherly
Wish to talk to someone who has these VG’s installed? Call us, we’d be happy to give you some names.
"We're There to Keep You in the Air"