Do delta wings typically not have flaps?

[aeromed202]

I always wondered. I know some use leading and trailing adjustable surfaces like the A4, but what about the Concord or Tu144? Do these rely on higher AoA's to maintain lift in slow flight situations? I ask for general learning as well as how these are modeled for FS9. Most deltas include a flaps section in the cfg, even if there is no visual animation to go along or no apparent flaps on the real thing. Are such situations there to address software/flight dynamics issues particular to delta wings and intrinsic to the game? Another aircraft would be the Vulcan, which does not seem to have flaps that I can see in pictures or videos.

[pfflyers]

Seems to me that the only way you could put flaps on a delta-wing aircraft would be if it had a seperate horizontal tail with elevators or a canard or some such to counteract the downward pitch that flaps would cause.

[Matt Wynn]

approach Alpha of a Mirage 2000:



they land fast by comparison to swept wings due to not having all that good lift at low speeds, as a result to keep the speed as low as possible you get the nose up and come in a bit quicker to compensate...

[Dev One]

I would think that simple deltas (Vulcan et al) cannot compensate for the pitching moment of flaps or slats unless they have either a tailplane (Gloster Javelin) or nose canards (Typhoon, Rafale, Viggen etc).
The lift of a Delta - e.g. Concorde is complex due to the vortex created from the leading edge curve, but typically the angle of attack is (or can be) a lot greater than straight or slightly swept wings. Thats not to mention the C of G shift used on Concorde using fuel to help compensate for umpteen things......
Keith

[aeromed202]

Those were the thoughts I had, so I'm sort of at a loss to understand why flap effects are added to some sim aircraft sporting delta wings, as well as some small definitely flap-less aircraft come to think of it.

[Matt Wynn]

Those were the thoughts I had, so I'm sort of at a loss to understand why flap effects are added to some sim aircraft sporting delta wings, as well as some small definitely flap-less aircraft come to think of it.

sometimes they control leading edge slats, but typically on deltas they start deploying as the airspeed decreases, some aircraft don't have them fitted, i have had to go round in the past editing out flap entries...

[Rallymodeller]

Since the trailing edge elevons on a pure-delta plane perform the same function as elevators and ailerons on a conventional aircraft, drooping the trailing edge for "flap action" on, say, a Mirage would force the nose down. Unless there is an airfoil to balance the pitching moment, flaps on a delta have the exact opposite effect as on a conventionally-laid-out aircraft. The only pure-delta aircraft I can think of that has flaps of a sort is the Tu-144, and the small retractable high-camber canards behind the cockpit perform the balancing function even though they have no control surfaces. They are so high lift that they can keep the Charger in the correct attitude for landing and take-off.

[Matt Wynn]

the trailing edge of the TU-144's canards are kinda unique too.... they have flaps on....

[stuartcox]

Alphasim's Eurofighter Typhoon...

Attachment 64710

[Matt Wynn]

now that looks wrong! heres real deal on short finals.... note Airbrake extended to keep speed down, but counteracting that and acting as it's equaliser is the thrust of them twin EJ200's.....

Attachment 64711

[Sunny9850]

Actually not wrong at all on the EF2000. It does have flaperons and leading edge slats and of course the canards. One function of any flap, if designed correctly is to alter the shape of the wing. Basically creating a "thicker" wing which in turn increases the lift of that wing at a given AoA.
That increase in lift, again given correct design parameters will be focused in the forward 1/3 and near the wing root, offsetting any pitch change caused by the flaperons.

The canard at the rear of the Tu-144 is showing exactly the same theory..by creating this curved shape a relatively small lifting surface creates a large amount of lift. Making the whole thing out of multiple surfaces allows flexibility and easier storage.

In case of older designs, DeltaDart and DeltaDagger the pure delta wing indeed simply needs a larger AoA and higher approach speeds to maintain sufficient lift.


I would be careful using pictures such as the EF2000 with the extended speed brake as a template for how that aircraft always approaches a runway. It is too easy, especially with a still relatively rare bird such as the Taifun to see demonstration flight pictures. Not normal, run of the mill flights.

Cheers
Stefan

[Matt Wynn]

i don't think i've ever noticed Typhoons flaps, even on approach into EGXC (Coningsby) being down, the slats yeah, but not the flaperons... i know that when shut down if the pilot has the stick forwards or off centre they hold their position, like the canards but the slats reset to form the wing instead of extending fore/down slightly to increase wing area....

some standard landings here in this guys album:
http://www.flickr.com/photos/nigelblake/2535016943/
http://www.flickr.com/photos/nigelbl...n/photostream/
http://www.flickr.com/photos/nigelbl...n/photostream/

slats clearly seen here during a display, they don't half protrude
http://www.aviationphoto.co.uk/RAF%2...ill%202010.jpg

she's a puzzle thats for sure..... i'll get on the blower to my contact at BAe Sys, if anything it'll be good to know so we can adjust tiffie and i'm always fiddling with the bally thing

F-102, F-106 yeah you really had to get the nose up for them.... and have the right speed, fall behind that power curve and approach path and it was bad news or a go-around and try again from what i've heard....

[Rallymodeller]

the trailing edge of the TU-144's canards are kinda unique too.... they have flaps on....

Those aren't really flaps. They are articulated sections that move upwards as the canard folds to lie conformally along the top of the fuselage. In other words, the canard "flattens out" as it folds back. There is a very small amount of movement in them to allow for trimming on approach, but it's automatic and no more than 1°-2°.

[SSI01]

A MSgt we had at Luke AFB had come from Malmstrom AFB, MT where he had been an F-106 mech. He and another acquaintance, a former F-102 maintainer, have both told me those two deltas had to keep a rather high AOA on approach with power up to compensate for no flaps - on the other hand, once they were on the ground holding the nose up as long as possible resulted in a fantastic braking action by that huge wing, meaning they were able to have relatively little main gear brake wear if the wing's aerodynamic braking action on the ground were taken advantage of, in conjunction with the brake 'chute.

[SSI01]

[Quote: Those were the thoughts I had, so I'm sort of at a loss to understand why flap effects are added to some sim aircraft sporting delta wings, as well as some small definitely flap-less aircraft come to think of it.[/QUOTE]

Another thought occurred to me, Matt or someone else who has written code for FSim aircraft could answer it better no doubt - the flap effect, even with no flaps, can be used to simulate the presence of a brake 'chute if one wasn't put in the model, even though the real aircraft uses one.

[Matt Wynn]

[Quote: Those were the thoughts I had, so I'm sort of at a loss to understand why flap effects are added to some sim aircraft sporting delta wings, as well as some small definitely flap-less aircraft come to think of it.

Another thought occurred to me, Matt or someone else who has written code for FSim aircraft could answer it better no doubt - the flap effect, even with no flaps, can be used to simulate the presence of a brake 'chute if one wasn't put in the model, even though the real aircraft uses one.[/QUOTE]

i believe it's possible, you'd have to adjust the amount of drag from the flaps to simulate it, then remember to not hit the things at low level

[aeromed202]

After looking at some images of the Typhoon and others, I can only assume that in this age of fly-by-wire, the leading and trailing edge surfaces get employed automatically whenever needed. But I guess one of my original questions was sort of answered. Models don't necessarily have accurate flap sections so I won't feel bad taking one out to increase the accuracy of the aircraft with other sections edited to make up for the change.

[Sunny9850]

i don't think i've ever noticed Typhoons flaps, even on approach into EGXC (Coningsby) being down, the slats yeah, but not the flaperons... i know that when shut down if the pilot has the stick forwards or off centre they hold their position, like the canards but the slats reset to form the wing instead of extending fore/down slightly to increase wing area....

some standard landings here in this guys album:
http://www.flickr.com/photos/nigelblake/2535016943/
http://www.flickr.com/photos/nigelbl...n/photostream/
http://www.flickr.com/photos/nigelbl...n/photostream/

slats clearly seen here during a display, they don't half protrude
http://www.aviationphoto.co.uk/RAF%2...ill%202010.jpg

she's a puzzle thats for sure..... i'll get on the blower to my contact at BAe Sys, if anything it'll be good to know so we can adjust tiffie and i'm always fiddling with the bally thing

F-102, F-106 yeah you really had to get the nose up for them.... and have the right speed, fall behind that power curve and approach path and it was bad news or a go-around and try again from what i've heard....

I am puzzled now myself, after watching the nice Ytube video of the 50th anniversary celebration of the JG74 where none of the Typhoon deployed anything. Slat or flaps...but of course they were air show light and showing off. With these modern birds the pilot makes a control input and the aircraft configures itself to make it happen. So the slats and flaps may just not have been needed.

Or I could be mistaken on the existence of flaps...could it have been the Saab Viggen that had them ??

Anyway...here is the video.
http://www.youtube.com/watch?v=Um9XH...e_gdata_player

Cheers
Stefan

[Rallymodeller]

A MSgt we had at Luke AFB had come from Malmstrom AFB, MT where he had been an F-106 mech. He and another acquaintance, a former F-102 maintainer, have both told me those two deltas had to keep a rather high AOA on approach with power up to compensate for no flaps - on the other hand, once they were on the ground holding the nose up as long as possible resulted in a fantastic braking action by that huge wing, meaning they were able to have relatively little main gear brake wear if the wing's aerodynamic braking action on the ground were taken advantage of, in conjunction with the brake 'chute.

The Saab J35 Draken has a little set of tailwheels for exactly that purpose. Because of the dispersed basing the Swedes use in an emergency, and because of the need to dramaticaly shorten both the takeoff and landing runs, Saab put the tailwheels in to allow the pilots to drag the tailcone on the ground with no fear of grinding the burner can off.

Incidentally, and to bring the conversation back around, actuating the flaps on Bookmark's freeware Draken pops the brake chute on landing. The doors close up again if you raise the flaps, but the chute isn't reloaded until you shut down and restart.

[Ferry_vO]

Or I could be mistaken on the existence of flaps...could it have been the Saab Viggen that had them ??

The Viggen has flaps but on the canard wing which itself doesn't move like it does on the Eurofighter, Rafale or Gripen.

The FsX Iris Vulcan uses the flaps to simulate various settings on the speedbrakes.

[AndyG43]

I am puzzled now myself, after watching the nice Ytube video of the 50th anniversary celebration of the JG74 where none of the Typhoon deployed anything. Slat or flaps...but of course they were air show light and showing off. With these modern birds the pilot makes a control input and the aircraft configures itself to make it happen. So the slats and flaps may just not have been needed.

Or I could be mistaken on the existence of flaps...could it have been the Saab Viggen that had them ??

Anyway...here is the video.
http://www.youtube.com/watch?v=Um9XH...e_gdata_player

Cheers
Stefan

No, Stefan, I think you are right; and right on all counts. Typhoon does have "flaperons" but probably doesn't use them much in airshow/light config (which would include Matt's Coningsby landings) as the onboard systems will make needed adjustments to maintain stability & controlability. I'd still be interested to hear what Matt's "contact" has to say on the matter, but that kinda makes sense to me.

[Matt Wynn]

"Pitch control is provided by symmetric operation of foreplanes and wing flaperons, while roll control is primarily achieved through differential operation of wing flaperons. Yaw control is primarily provided by the fin mounted rudder. Cross feeds among the various actuation systems are also implemented to optimise aircraft performance and handling qualities. The slats and flaperons automatically optimise the wing camber at all Angles of Attack (AOA)." - Eurofighter.com

have left a message with my buddy, will report back when i hear anything... :salute:

[Matt Wynn]

just had this in from my contact:

"I've not seen any official docs or simulation on the subject unfortunately.

This page

http://www.eurofighter.com/capabilit...ol-system.html

says that the flaperons are for pitch control (along with the canards), the majority of roll control, and optimisation of camber along with the leading edge slats.

I've never known them used as "flaps" in the traditional sense"

[Sunny9850]

Flaperons to control the camber of the wing....that is the traditional sense. As I said earlier the idea is to create a "thicker wing" which generates more lift at a lower airspeed combined with an increase in drag to allow a steeper descent without increasing the aircrafts speed.

It really doesn't get any more traditional than that. Some flaps do a better job of one aspect or another but in the end that is what all of them aim to do.
Simple hinged flaps may do more in the drag area than in the addition of lift and highly complex fowler flaps, such as what you find on a 747 create huge amounts of additional lift by radically changing the camber or aerodynamic profile of the wing.

The text from Eurofighter.com also points out that the flaperons, along with the slats, perform this function automatically as I had suspected. The pilot simply moves the flight controls where he wants the airplane to point and the throttle to give him the speed he desires...the airframe and computers simply make that happen...as far as possible.

Cheers
Stefan

[Matt Wynn]

the most i've seen in travel is a few inches but never more...

Attachment 64734
^Fully Up, neutral control surfaces....

Attachment 64738
^'Standard' landing, maybe 3 inches of travel....

what i'm thinking he means is that the droop on the trailing edge, being computer driven, changes the overall shape of the wing, kinda like how flaps travel down and back to increase lift area in conjunction with the slats... as opposed to the general droop of the surfaces in totality... if that kinda makes sense....