What is this????

NoJoy

NoJoy

Piston banger
Pardon my ignorance,

This Bonanza pulled up on the ramp with this strange trailing edge wing mod . No one at my Flight school school has a clue what this is, could anyone please enlighten us.

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I would try searching but don't know what to search for!
Thanks in advance again guys!
 
That triangle/wedge thing on the leading edges is on the new Bonanzas. I don't know what year it started, but the '07 I was flying had them. There's nothing in the POH to describe what they are or what they do. I assumed they were some kind of stall strip.

As for the TKS theories, the Bonanzas without TKS still have the wedges.
 
I believe that's a fairly large stall strip, and I've seen them on other Bonanza's. Dunno why they make them so big for that wing, but it's not unheard of.
 
Wow now I feel dumb lol, in my defense I wrote that rushing in between students. I meant Leading Edge... :biggrin:

Oh okay stall strip.. Thanks a lot again guys.
 
I read the thread on BeechTank (hee-hee!) and the OP kept calling it a vortex generator. They removed the existing VGs, I guess because they also collect ice, but couldn't be given a weeping device. They also modified the stall strips with foam to wick fluid behind them.
 
hotbwayjoel said:
This Bonanza pulled up on the ramp with this strange trailing edge wing mod . No one at my Flight school school has a clue what this is, could anyone please enlighten us.
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They give the ailerons some effectiveness in stall by creating turbulent flow. Turbulent flow is less susceptible, when compared with laminar flow, to separation associated with stall. Hence the reason vortex generators work to reduce stall speed.
 
shdw said:
They give the ailerons some effectiveness in stall by creating turbulent flow. Turbulent flow is less susceptible, when compared with laminar flow, to separation associated with stall. Hence the reason vortex generators work to reduce stall speed.
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Say what?

They create turbulent airflow to induce buffeting of flight controls before a stall occurs so that you can feel it coming. Turbulent flow separates earlier. Vortex generators are essentially "adding" energy into the system to keep airflow attached. Think slotted flaps for the upper surface. Not so much spoilers.
 
ProudPilot said:
Say what?

They create turbulent airflow to induce buffeting of flight controls before a stall occurs so that you can feel it coming. Turbulent flow separates earlier. Vortex generators are essentially "adding" energy into the system to keep airflow attached. Think slotted flaps for the upper surface. Not so much spoilers.
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Vortex generators also be used to create vorticies(!) that re-energize the boundary layer from the free stream, delaying separation further back along the wing and increasing control effectiveness.
 
Ah, I would say that is the oddest looking vortex generator ever. I'm used to them having a substantial angle on them to start the air moving.
 
ProudPilot said:
I'm used to them having a substantial angle on them to start the air moving.
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They do, comparatively to the rest of the wing. Think of the wing in a stalled configurations, that's when these create strong vortices. During cruise you don't want them creating strong vortices, because that's drag that hurts performance.

OP: They are not stall strips.

The job of a stall strip is to force a portion of the wing to stall before another portion of the wing. For a safe design we want the root to stall before the tip. In other words, you'll find stall strips near the wing root. A stall strip out over the ailerons would not be desired or useful.
 
shdw said:
They do, comparatively to the rest of the wing. Think of the wing in a stalled configurations, that's when these create strong vortices. During cruise you don't want them creating strong vortices, because that's drag that hurts performance.

OP: They are not stall strips.

The job of a stall strip is to force a portion of the wing to stall before another portion of the wing. For a safe design we want the root to stall before the tip. In other words, you'll find stall strips near the wing root. A stall strip out over the ailerons would not be desired or useful.
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No, No, ... no...

Depending on the aircraft. Cessna and Piper have even used them both ways. Read the POH. Many aircraft have stall strips to induce buffeting over the flaps or ailerons to create the sensation before the stall. Some aircraft have strips to deepen the stall at the root and make it stall differently. However, the only true way to make the wing stall at the root is with wing design. Primary reasons to have the wing stall at the root is washout and rectangular wings. Please, someone post PHAK or another aerodynamics slide quick! I've got other homework to do right now!
 
ProudPilot said:
Say what?

They create turbulent airflow to induce buffeting of flight controls before a stall occurs so that you can feel it coming. Turbulent flow separates earlier.
Click to expand...

Turbulent flow is noted by a higher Reynolds number. And a higher Reynolds number translates to a greater value of Cl max. In other words, higher Reynolds/turbulent flow number means more kinetic energy exists within the boundary layer. Kinetic energy within the boundary layer is what pushes the boundary layers stagnation point reward along the wings chord. The stagnation point of the boundary layer is where separation occurs and reverse flow beings (stall).

On page 56/57 of Aerodynamics for Naval Aviators there is some information on separated flow and, on page 52, the boundary layer. Though it's a bit vague.
 
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