DISCUSSION ON BUILDING NEW GENERATION PLANES

[Ketchup]

Also does anybody have an example on how the prandtl wings actually work? If I understand correctly, when the plane yaws one wing is going faster than the other, so the drag increases and it slows back down until they are both at the same speed. Is that correct?

 

[Scotto]

The Prandel stuff is cool but it would probly not handle the sound barrier well not that we are going to come close to it but just in spirit or somthing.
Leaded50s comment about birds heads helping turn made me think about the concorde looking side to side or an F86-ish thing ducting intake and exhaust. Itd be cool maybe a little funny looking at extreme angles but would it work at mach 2?

This is what the military are working on, lots of tailless aircraft.

All I am saying is I haven't seen anybody design and fly one. I feel someone can resolve the problems with a gyro and get an Rc model to fly.

This video was cool but so rapid fire its hard to watch. Are some of them switching modes from being flat(stealth cruise) to Vtail?

 

[Taildragger]

It isn’t as effective as a normal turn, but planes can definitely steer effectively with the wings level. Most of the time when I fly my crack yak I actually do flat turns at low speeds. If you roll a plane 90 degrees and use elevator to turn, it is similar to using only rudder except the rudder is smaller than elevator.

but when it is banked the wings make lift in the direction of the turn.

 

[Flyingshark]

Also does anybody have an example on how the prandtl wings actually work? If I understand correctly, when the plane yaws one wing is going faster than the other, so the drag increases and it slows back down until they are both at the same speed. Is that correct?

Best article I've seen. Doesn't explain the theory very helpfully though.
https://www.nasa.gov/centers/armstrong/programs_projects/PRANDTL/overview.html

 

[Ketchup]

but when it is banked the wings make lift in the direction of the turn.

Like I said, it isn't as effective as a banked turn, but it isn't fair to say that wings level turns aren't effective at all (it depends on the plane as well, since some do it even better than banked turns).

 

[Mr_Stripes]

I think it depends on the shape of the wings. I don't think the B2 is cool, but this (F/A-XX concept) is:
View attachment 209192

eh its okay

 

[Mr_Stripes]

What it the elevons had 2 control surfaces. That way if you wanted to turn right you have one surface go up and the other go down. It would look like a v shape from the side. I don't know how to explain my idea better. I need to get a piece of fb and show you guys.

 

[Flyingshark]

What it the elevons had 2 control surfaces. That way if you wanted to turn right you have one surface go up and the other go down. It would look like a v shape from the side. I don't know how to explain my idea better. I need to get a piece of fb and show you guys.

Like this?

 

[Scotto]

What it the elevons had 2 control surfaces. That way if you wanted to turn right you have one surface go up and the other go down. It would look like a v shape from the side. I don't know how to explain my idea better. I need to get a piece of fb and show you guys.

Or this https://forum.flitetest.com/index.php?threads/split-elevon-wing-test.67556/ ?

Whats it called when a canard can help steer? Canarderon?

 

[LitterBug]

Like I said, it isn't as effective as a banked turn, but it isn't fair to say that wings level turns aren't effective at all (it depends on the plane as well, since some do it even better than banked turns).

Just throwing a few thoughts out to this thread:

Flat turns with wings are for the most part inefficient. More air goes over one wing than the other causing one side to lift, the other to drop, in turn causing bank/roll. Attempts to keep a wing level through a yaw only turn are wasting energy keeping the wing level. The idea behind Prandtl wing design is to minimize adverse yaw for a naturally more efficient and coodinated flight.

 

[leaded50]

What it the elevons had 2 control surfaces. That way if you wanted to turn right you have one surface go up and the other go down. It would look like a v shape from the side. I don't know how to explain my idea better. I need to get a piece of fb and show you guys.

At the first jet (Coanda) they used a cross -shaped tail with 4 parts as rudder/elevator.

But... then you will not have a new generation rudderless plane......who was the intention here..

 

[foamboardflyer]

Just throwing a few thoughts out to this thread:

Flat turns with wings are for the most part inefficient. More air goes over one wing than the other causing one side to lift, the other to drop, in turn causing bank/roll. Attempts to keep a wing level through a yaw only turn are wasting energy keeping the wing level. The idea behind Prandtl wing design is to minimize adverse yaw for a naturally more efficient and coodinated flight.

But what if you were landing the aircraft and you have a cross wind, and your flying a stealth jet (your aircraft has no rudder) You can’t roll the aircraft while landing it. you need a way to control yaw (even if its not 100% efficient) also I thought the idea of rudderless aircraft was for stealth not efficiency.

 

[L Edge]

Like this?
View attachment 209248

Rotate the rudders in the video (NOW ELEVATOR) and you have hit the nail on the head. I explored airbrakes. Concept works, need finer control.
Put plane vertically down and it would watch it slow up (gyrated due to sloppyness).

 

[L Edge]

Simply put, the rudderless models(B1,B2 and X-47B and future 6 generation planes ) do incorporate yaw components in order to fly. When you do, the other 2 axis are usually changed which need to be compensated. Only way I know is to add programable gyros to account for that.

Now that is why I say you need to get into AS3X to solve the problems.

 

[LitterBug]

But what if you were landing the aircraft and you have a cross wind, and your flying a stealth jet (your aircraft has no rudder) You can’t roll the aircraft while landing it. you need a way to control yaw (even if its not 100% efficient) also I thought the idea of rudderless aircraft was for stealth not efficiency.

You can still yaw a basic wing using split elevons or other drag inducing measures as others have mentioned before in this thread. Stealth AND efficiency are both important. Aero Efficiency leads to higher speeds, Higher load carrying capacity, better range, etc...

 

[Mr_Stripes]

Rotate the rudders in the video (NOW ELEVATOR) and you have hit the nail on the head. I explored airbrakes. Concept works, need finer control.
Put plane vertically down and it would watch it slow up (gyrated due to sloppyness).

Thats what I was thinking.

 

[jfaleo1]

What happens if you were to use only one airleron control surface for each wing....
Ie . When rolling left only the left airleron moves up this will create more drag on the wing so will slow it down while also rolling.... Just a theory.....

There is also an added fact that this arrangement rolls in an odd way. it does not roll around the center axis of the airplane but rather about (approximately) the center of span of the opposite wing. not optimal. it has been used in many aircraft including the Beechjet (Mu-300 Diamond) and Mu-2, as well as many business jets like the Citations that I teach as low speed roll augmentation which has been noted has been noted.

 

[Marzipan]

yeh...antigrav and impulse...that's what we need to solve these issues. without them we're hooped.

 

[FlyingMonkey]

What it the elevons had 2 control surfaces. That way if you wanted to turn right you have one surface go up and the other go down. It would look like a v shape from the side. I don't know how to explain my idea better. I need to get a piece of fb and show you guys.

I think what you're suggesting, is called split elevons.

 

[kilroy07]

split ailerons that is how the b2 and other wings handle yaw...