justinb138 0 #1 March 26, 2005 I've seen these things on the wings of the otter, but have no idea what they are/what their purpose is. Can someone enlighten me? Quote Share this post Link to post Share on other sites
jonstark 8 #2 March 26, 2005 Stall fences. They help keep a stall of the wing limited to the inboard section leaving the ailerons with some control. Quote Share this post Link to post Share on other sites
justinb138 0 #3 March 26, 2005 Thanks Quote Share this post Link to post Share on other sites marks 0 #4 March 26, 2005 hyper canopies has the same thing. they help with reducing the vortacies during slow flight, wich helps slower flight performance, like flare. beezy shaw will be able to give a better explanation. Quote Share this post Link to post Share on other sites airtwardo 7 #5 March 26, 2005 Quotehyper canopies has the same thing. they help with reducing the vortacies during slow flight, wich helps slower flight performance, like flare. beezy shaw will be able to give a better explanation. Quote But increasing the vortacies on the top skin gives MORE lift ~ If you choke a Smurf, what color does it turn? ~ Quote Share this post Link to post Share on other sites Groundbound 0 #6 March 26, 2005 Stall fences are thin plates of metal mounted on the top of the wing, projecting upwards, aligned in the same orientation as the direction of flight. Their purpose is to reduce the spanwise (root to tip) flow of air, thus maintaining boundary layer thickness (delaying the stall) and enhancing aileron control at high angles of attack. They keep the airplane in better control at lower airspeeds such as when jumpers are exiting. . . . ignore this for now: Quote Share this post Link to post Share on other sites airtwardo 7 #7 March 26, 2005 They keep the airplane in better control at lower airspeeds such as when jumpers are exiting. Quote Though spanwise...aren't they still a VG of sorts? ~ If you choke a Smurf, what color does it turn? ~ Quote Share this post Link to post Share on other sites jonstark 8 #8 March 26, 2005 They aren't VGs. What they help to do is to keep a stall from moving outboard along the wing. The wing has a certain amount of "wash-out" or twist to make the inboard end stall first but leave the outboard end flying as the a/c recovers. The fences assist in preventing stall propagation outboard. This can also be done with vortelons which are small sticky-outy thingys on the lower leading edges at about the same location. Look on a Gulfstream IV. Vortex generators make small vortices which excite the boundry layer and keep it closer to the wing in high angles of attack. This gives the wing more efffective lift at slower speeds. For example, my Stinson takes off at 45 mph with them but 60+ without them. Landing performance is similar but I am too busy landing to look down at the airspeed to give you an accurate number. The Gulfstream II has fences which stick up about 8" for the entire chord of the wing. They have VGs outboard of the fences and in front of the ailerons. Another place where VGs are effective is over the cockpit of jets. There is a mach buffet on some which can be extremely noisey. Carefully located VGs move this rearwards a couple of feet and away from the pilots' heads. Quote Share this post Link to post Share on other sites airtwardo 7 #9 March 26, 2005 The fences assist in preventing stall propagation outboard. Quote That description works!Must be my ethnic background... I knew they weren't actual VG's but I thought they worked 'like' them...your explaination is clear. ~ If you choke a Smurf, what color does it turn? ~ Quote Share this post Link to post Share on other sites larsrulz 0 #10 March 26, 2005 QuoteThey aren't VGs. While they aren't a vortex generator, they are a "vortex generator of sorts." They work by producing a vortex, which in turn takes the spanwise flow of the wing and turn it parallel to the line of flight. The biggest difference is that vortex generators directly influence the boundary layer of a wing, pumping energy into it so it will stay attached at high lift, while fences and vortilons indirectly effect the boundary layer by influencing the potential flow (flow in which vorticity is zero). But, you know....details. I got a strong urge to fly, but I got no where to fly to. -PF Quote Share this post Link to post Share on other sites DBCOOPER 5 #11 March 29, 2005 QuoteStall fences. They keep the crew dogs in.Replying to: Re: Stall On Jump Run Emergency Procedure? by billvon If the plane is unrecoverable then exiting is a very very good idea. Quote Share this post Link to post Share on other sites JustaBill 0 #12 March 29, 2005 small sticky-outy thingys is that an aircraft technical term??? ------------------------------------------------ I've done so much, with so little, for so long I'm now expected to do everything with nothing forever Quote Share this post Link to post Share on other sites pilotdave 0 #13 March 29, 2005 Quotesmall sticky-outy thingys is that an aircraft technical term??? If you said it in french, probably. Many of those technical for airplane parts are in french for some reason. I never figured out how that happened since they first showed up on american designs. ie canard, aileron, etc. Dave Quote Share this post Link to post Share on other sites billvon 3,111 #14 March 29, 2005 >I never figured out how that happened since they first showed up on american designs. ie canard, aileron, etc. And on bikes. I'm with Sheldon Brown - we should all decide to start calling them derailers instead of derailleurs. Quote Share this post Link to post Share on other sites Join the conversation You can post now and register later. If you have an account, sign in now to post with your account. Note: Your post will require moderator approval before it will be visible. Reply to this topic... × Pasted as rich text. Paste as plain text instead Only 75 emoji are allowed. × Your link has been automatically embedded. Display as a link instead × Your previous content has been restored. Clear editor × You cannot paste images directly. Upload or insert images from URL. 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marks 0 #4 March 26, 2005 hyper canopies has the same thing. they help with reducing the vortacies during slow flight, wich helps slower flight performance, like flare. beezy shaw will be able to give a better explanation. Quote Share this post Link to post Share on other sites
airtwardo 7 #5 March 26, 2005 Quotehyper canopies has the same thing. they help with reducing the vortacies during slow flight, wich helps slower flight performance, like flare. beezy shaw will be able to give a better explanation. Quote But increasing the vortacies on the top skin gives MORE lift ~ If you choke a Smurf, what color does it turn? ~ Quote Share this post Link to post Share on other sites
Groundbound 0 #6 March 26, 2005 Stall fences are thin plates of metal mounted on the top of the wing, projecting upwards, aligned in the same orientation as the direction of flight. Their purpose is to reduce the spanwise (root to tip) flow of air, thus maintaining boundary layer thickness (delaying the stall) and enhancing aileron control at high angles of attack. They keep the airplane in better control at lower airspeeds such as when jumpers are exiting. . . . ignore this for now: Quote Share this post Link to post Share on other sites
airtwardo 7 #7 March 26, 2005 They keep the airplane in better control at lower airspeeds such as when jumpers are exiting. Quote Though spanwise...aren't they still a VG of sorts? ~ If you choke a Smurf, what color does it turn? ~ Quote Share this post Link to post Share on other sites
jonstark 8 #8 March 26, 2005 They aren't VGs. What they help to do is to keep a stall from moving outboard along the wing. The wing has a certain amount of "wash-out" or twist to make the inboard end stall first but leave the outboard end flying as the a/c recovers. The fences assist in preventing stall propagation outboard. This can also be done with vortelons which are small sticky-outy thingys on the lower leading edges at about the same location. Look on a Gulfstream IV. Vortex generators make small vortices which excite the boundry layer and keep it closer to the wing in high angles of attack. This gives the wing more efffective lift at slower speeds. For example, my Stinson takes off at 45 mph with them but 60+ without them. Landing performance is similar but I am too busy landing to look down at the airspeed to give you an accurate number. The Gulfstream II has fences which stick up about 8" for the entire chord of the wing. They have VGs outboard of the fences and in front of the ailerons. Another place where VGs are effective is over the cockpit of jets. There is a mach buffet on some which can be extremely noisey. Carefully located VGs move this rearwards a couple of feet and away from the pilots' heads. Quote Share this post Link to post Share on other sites
airtwardo 7 #9 March 26, 2005 The fences assist in preventing stall propagation outboard. Quote That description works!Must be my ethnic background... I knew they weren't actual VG's but I thought they worked 'like' them...your explaination is clear. ~ If you choke a Smurf, what color does it turn? ~ Quote Share this post Link to post Share on other sites
larsrulz 0 #10 March 26, 2005 QuoteThey aren't VGs. While they aren't a vortex generator, they are a "vortex generator of sorts." They work by producing a vortex, which in turn takes the spanwise flow of the wing and turn it parallel to the line of flight. The biggest difference is that vortex generators directly influence the boundary layer of a wing, pumping energy into it so it will stay attached at high lift, while fences and vortilons indirectly effect the boundary layer by influencing the potential flow (flow in which vorticity is zero). But, you know....details. I got a strong urge to fly, but I got no where to fly to. -PF Quote Share this post Link to post Share on other sites
DBCOOPER 5 #11 March 29, 2005 QuoteStall fences. They keep the crew dogs in.Replying to: Re: Stall On Jump Run Emergency Procedure? by billvon If the plane is unrecoverable then exiting is a very very good idea. Quote Share this post Link to post Share on other sites
JustaBill 0 #12 March 29, 2005 small sticky-outy thingys is that an aircraft technical term??? ------------------------------------------------ I've done so much, with so little, for so long I'm now expected to do everything with nothing forever Quote Share this post Link to post Share on other sites
pilotdave 0 #13 March 29, 2005 Quotesmall sticky-outy thingys is that an aircraft technical term??? If you said it in french, probably. Many of those technical for airplane parts are in french for some reason. I never figured out how that happened since they first showed up on american designs. ie canard, aileron, etc. Dave Quote Share this post Link to post Share on other sites
billvon 3,111 #14 March 29, 2005 >I never figured out how that happened since they first showed up on american designs. ie canard, aileron, etc. And on bikes. I'm with Sheldon Brown - we should all decide to start calling them derailers instead of derailleurs. Quote Share this post Link to post Share on other sites
