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Old Oct 17, 2012, 05:11 PM
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Originally Posted by LuvEvolution7 View Post
Flying Scot, noone said anything about drag due to surface deflection. the bottom line is, that on a Delta planform, when you deflect a surface you get a net total loss of lift, which decreases speed during a turning maneuver. this is generally accepted in the aerodynamic fraternity and certainly one of the basic things taught at Royal Military College (where I attended school) and many others around the world. that fact is irrefutable.

you have said in the other thread that you plan to build a model that flies like the full size Concorde. hate to bust your bubble, but no matter what you do, an RC model will never fly like a full size plane. plain and simple. don't believe me, go ask around or simply try it and fail. build a model to replicate the full size as best you can, but never expect it to fly the same, cause it just won't happen.

this is where we tend to design as a model and not per full size. this also where I happen to agree with you about full size airfoils being used on models. it's generally accepted that this does not work...................because models don't fly like full size planes. however, I do differ with you a bit, because it's also generally accepted that any airfoil shape will work on an RC model..................even a flat plate, as you said. the measurement of drag between the two at RC scale is barely measurable. this is why I disagree with you about the full size airfoil being utilized on a model Concorde. at model scale, we can take advantage of the full size design, because it was optimized at the LE for maximum vortex generation at lower speeds. this could be a benefit to a model, as we discovered with the Chimera Delta. as far as the rest of the shape....................the wing was designed for Mach flight and I agree that the shape will probably not be good for flight. the one good thing about a model, is that it will generally be overpowered and any airfoil issues will normally be blanked out by raw power.
It seems we are splitting hairs - do explain how a loss of lift causes a reduction in speed - loss of lift surely will cause the plane to dive - increasing speed - the only thing that will cause the speed to bleed off is loss of thrust or an increase in drag

I know i can never get a model to behave like the full size plane............the challenge is to make people think/question..............is that the real Concorde. and i am not talking about flying at the local flying club..

If you think you can generate the useful formation of large low pressure vortices over the entire upper wing surface of a Concorde model flying at what 30 mph well that will be something to see.. Concorde on approach and landing was significantly over powered and was flown on the throttles (autothrottle) not the control column now that is going to be some trick to do that on a model.

I totally fail to see why a wing designed for flight at Mach 2 would need to be replicated in a model that will never get anywhere near even the take off speed of the full sized plane except for visual reasons - i certainly dont have the mindset or the patience or the time to do that

Finally i hate to add as soon as something is generally accepted as fact you can be sure it is wrong.

bed time
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Old Oct 17, 2012, 05:34 PM
clsink1128
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United States, IA, Burlington
Joined Aug 2011
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From what i've seen from DD, I have faith that his Concords will fly. He's got that never give up mentality. What he sets his mind up to do, you might as well consider it a done deal. Besided that, you'll never know till ya try. I applaud everybody on rcg for their efforts and wish them all the best "even the critics".
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Old Oct 17, 2012, 08:23 PM
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Originally Posted by clsink1128 View Post
From what i've seen from DD, I have faith that his Concords will fly. He's got that never give up mentality. What he sets his mind up to do, you might as well consider it a done deal. Besided that, you'll never know till ya try. I applaud everybody on rcg for their efforts and wish them all the best "even the critics".
Amen Boss! I hope to get the BOAC Corde skyward soon.
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Old Oct 17, 2012, 11:02 PM
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St.Catharines, Ontario
Joined Jan 2009
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Originally Posted by Flying_Scot View Post
It seems we are splitting hairs - do explain how a loss of lift causes a reduction in speed - loss of lift surely will cause the plane to dive - increasing speed - the only thing that will cause the speed to bleed off is loss of thrust or an increase in drag

I know i can never get a model to behave like the full size plane............the challenge is to make people think/question..............is that the real Concorde. and i am not talking about flying at the local flying club..

If you think you can generate the useful formation of large low pressure vortices over the entire upper wing surface of a Concorde model flying at what 30 mph well that will be something to see.. Concorde on approach and landing was significantly over powered and was flown on the throttles (autothrottle) not the control column now that is going to be some trick to do that on a model.

I totally fail to see why a wing designed for flight at Mach 2 would need to be replicated in a model that will never get anywhere near even the take off speed of the full sized plane except for visual reasons - i certainly dont have the mindset or the patience or the time to do that

Finally i hate to add as soon as something is generally accepted as fact you can be sure it is wrong.

bed time
hmmmmmmmmmmmmm, how does loss of lift cause a reduction in speed. easy answer if you think about it................pilot yanks and banks, surface deflection causes total net loss of lift, which also creates drag which causes plane to slow down. plane starts to drop out of sky, so pilot has to increase power and and also increase control input to maintain height. either brute power has to deacrease rate of decent, or pilot has to cease the turn. one or the other. again, simple aerodynamics and laws of physics. look man, this isn't my theory, but a fact. go watch a Eurofighter at an airshow. yankin and bankin causes an extreme amount of speed to bleed off in a rather alarming manner. even in full burner. the pilot ceases the maneuver and the speed builds up fast. the use of canards somewhat eases the speed bleed, but it's still alarmingly apparent.

as you said, a delta does not behave like a normal airplane and therefore doesn't necessarily pick up speed in a dive towards the ground when lift is lost. most of the time, they tend to sit up on their tails and kinda just mozy on into the ground tail first. go watch the Grippen crash video on youtube. classic delta, high AOA crash for a delta. they generally don't mush over nose first and pick up speed. I designed the Chimera delta and flight testing proved this. you are right that deltas don't stall in the normal sense of the word. and for the record, the vortex forms on the LE at any subsonic speed. you just need AOA to form it. the more AOA present, the larger the vortex becomes. the model flight testing proves this, because it just kinda lulls there like a full size delta. the only way that can happen, is if a vortex is formed and flowing down the LE in what you would call post stall maneuvering. for a normal plane.

also, the Chimera was designed to directly test the wing planform and its flight characteristics for Sam and Chris's Concorde build. the airfoils are almost identical to the full size Concorde and let me tell you, she flies beautifully, with just a slight hint of dutch roll at cruise. high speed flight is as if on rails and high AOA, slow flight is just as amazing. this is all without any gyros.

not sure where you get 30 MPH from either. if it's anything like other EDF's in the same wing loading class, she's gonna need more than that, just to float in. some of my small EDF's need 45 MPH to stay airborne. my small ones operate at or above 100 MPH. you need to stop thinking about that slow poke WOT4 you got (yeah, I have a few of em too) and start thinking high wing loading and high speed. you actually need to fly an EDF, not float it in.

speaking of that. you said something about holding high AOA on landing approach. something about Concorde using throttle for approach while holding constant AOA for finals........................that's standard for RC EDF/jet approach. if you fly properly, you set your finals and a proper AOA, then use fine adjustments of throttle to increase or decrease height. I never land less than 25% throttle. sometimes as high as 50% throttle, depending on flap settings. with the Chimera, we typically land at a constant 15 degrees AOA (or so) and use 25-50% throttle to touchdown. easy to do once you get used to it..............and all with no gyros.

Rich
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Old Oct 18, 2012, 11:04 AM
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Canada, ON, Mississauga
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Originally Posted by LuvEvolution7 View Post

also, the Chimera was designed to directly test the wing planform and its flight characteristics for Sam and Chris's Concorde build. the airfoils are almost identical to the full size Concorde and let me tell you, she flies beautifully, with just a slight hint of dutch roll at cruise. high speed flight is as if on rails and high AOA, slow flight is just as amazing. this is all without any gyros.


Rich

Amen Rich.....
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Old Jul 02, 2013, 08:40 PM
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The Long Thin Anglo-French Girl

Well today I got back to work on my two 100" Concordes I began to add spackle to the areas of the Nose & tail that need it, then I will get back to the wings, intakes, then laminate the nose & tail before they are molded.
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Old Jul 03, 2013, 01:16 AM
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Concorde's wings

Tonight I've spent another 2-3 hours sanding the right & left solid foam wings . . . .If I knew 2 years ago what i know now I would have had SilverFox CNC these Damm wings for me Lol

So next I'll add more spackle, then more sanding then I will laminate these wings with 3-4oz fiberglass, then I will mold them.
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Old Jul 03, 2013, 09:49 AM
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United Kingdom, Motherwell
Joined Aug 2012
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Originally Posted by LuvEvolution7 View Post
hmmmmmmmmmmmmm, how does loss of lift cause a reduction in speed. easy answer if you think about it................pilot yanks and banks, surface deflection causes total net loss of lift, which also creates drag which causes plane to slow down. plane starts to drop out of sky, so pilot has to increase power and and also increase control input to maintain height. either brute power has to deacrease rate of decent, or pilot has to cease the turn. one or the other. again, simple aerodynamics and laws of physics. look man, this isn't my theory, but a fact. go watch a Eurofighter at an airshow. yankin and bankin causes an extreme amount of speed to bleed off in a rather alarming manner. even in full burner. the pilot ceases the maneuver and the speed builds up fast. the use of canards somewhat eases the speed bleed, but it's still alarmingly apparent.

as you said, a delta does not behave like a normal airplane and therefore doesn't necessarily pick up speed in a dive towards the ground when lift is lost. most of the time, they tend to sit up on their tails and kinda just mozy on into the ground tail first. go watch the Grippen crash video on youtube. classic delta, high AOA crash for a delta. they generally don't mush over nose first and pick up speed. I designed the Chimera delta and flight testing proved this. you are right that deltas don't stall in the normal sense of the word. and for the record, the vortex forms on the LE at any subsonic speed. you just need AOA to form it. the more AOA present, the larger the vortex becomes. the model flight testing proves this, because it just kinda lulls there like a full size delta. the only way that can happen, is if a vortex is formed and flowing down the LE in what you would call post stall maneuvering. for a normal plane.

also, the Chimera was designed to directly test the wing planform and its flight characteristics for Sam and Chris's Concorde build. the airfoils are almost identical to the full size Concorde and let me tell you, she flies beautifully, with just a slight hint of dutch roll at cruise. high speed flight is as if on rails and high AOA, slow flight is just as amazing. this is all without any gyros.

not sure where you get 30 MPH from either. if it's anything like other EDF's in the same wing loading class, she's gonna need more than that, just to float in. some of my small EDF's need 45 MPH to stay airborne. my small ones operate at or above 100 MPH. you need to stop thinking about that slow poke WOT4 you got (yeah, I have a few of em too) and start thinking high wing loading and high speed. you actually need to fly an EDF, not float it in.

speaking of that. you said something about holding high AOA on landing approach. something about Concorde using throttle for approach while holding constant AOA for finals........................that's standard for RC EDF/jet approach. if you fly properly, you set your finals and a proper AOA, then use fine adjustments of throttle to increase or decrease height. I never land less than 25% throttle. sometimes as high as 50% throttle, depending on flap settings. with the Chimera, we typically land at a constant 15 degrees AOA (or so) and use 25-50% throttle to touchdown. easy to do once you get used to it..............and all with no gyros.

Rich
you are not reading what i wrote

It seems we are splitting hairs - do explain how a loss of lift causes a reduction in speed - loss of lift surely will cause the plane to dive - increasing speed - the only thing that will cause the speed to bleed off is loss of thrust or an increase in drag


What you wrote in a long winded way just agrees with my last sentence.....and does not answer the first question i posed.
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Old Jul 03, 2013, 06:04 PM
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Originally Posted by Flying_Scot View Post
you are not reading what i wrote

It seems we are splitting hairs - do explain how a loss of lift causes a reduction in speed - loss of lift surely will cause the plane to dive - increasing speed - the only thing that will cause the speed to bleed off is loss of thrust or an increase in drag


What you wrote in a long winded way just agrees with my last sentence.....and does not answer the first question i posed.
Hmmm I understand Sir, yes I see your point of view, I'm on the trolley . . .Visa-Vie air-go I understand.
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Old Jul 03, 2013, 06:07 PM
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Today I started what I HOPE is the last bit of sanding on the BOAC Concorde's Fuselage before I laminate it prior to molding it.
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Old Jul 03, 2013, 07:28 PM
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United States, GA, Atlanta
Joined Dec 2007
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Originally Posted by demondriver View Post
Today I started what I HOPE is the last bit of sanding on the BOAC Concorde's Fuselage before I laminate it prior to molding it.
This plane is going to look slick DD. Nice job Sir
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Old Jul 03, 2013, 07:46 PM
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This plane is going to look slick DD. Nice job Sir
Thats if I ever getit Done lol . . .I will though i will have her done by late August.

Thankyou Paul!
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Old Jul 03, 2013, 08:41 PM
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The fuse reminds me of an eel, Looking good DD!
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Old Jul 03, 2013, 08:50 PM
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The fuse reminds me of an eel, Looking good DD!
I kinda see what you mean Glen!

Thanks!
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Old Jul 04, 2013, 06:01 AM
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I kinda see what you mean Glen!

Thanks!
Looks kinda like seaview!
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