Prandtl-d Aircraft

[TwanV]

Prandtl's elliptical wing theory is nothing new, but I very much enjoyed the youtube explanation of the advantages of such a wing loading. If I remember correctly from fluid-dynamics lectures at university/Andersons Introduction to Flight, the wing design of the WW2 Spitfire is a good example of a real-life application of this theory. Those early aerodynamicists knew their game...

[olefud]

I'm studying about f1 aerodynamics and this is the first time that I encounter. words are new to me, especially the drag. What is drag? it's all about hindering the downforce. I don't understand. guys, could lend some information about f1 aerodynamics? I'm not engineer so I don't have enough reference about the topic. I researched also the net, but it entails about the schools and refer to this site. I want to study the formula one, without studying in the university.

Much of the (published) aero will have to do with flight. Fortunately this is largely applicable to land vehicles. Keep in mind that ground effect is the main difference. Google "aero drag" and you’ll have a working answer.

[NoDivergence]

Prandtl's elliptical wing theory is nothing new, but I very much enjoyed the youtube explanation of the advantages of such a wing loading. If I remember correctly from fluid-dynamics lectures at university/Andersons Introduction to Flight, the wing design of the WW2 Spitfire is a good example of a real-life application of this theory. Those early aerodynamicists knew their game...

Except they had to introduce washout to the wing for stall considerations, funnily enough giving a nonelliptical lift distribution

[autogyro]

https://www.youtube.com/watch?v=y9633v6U0wo

https://www.youtube.com/watch?v=VFk5Y_F-dwg

http://www.aviastar.org/helicopters_eng ... todyne.php

If this post disappears I suppose it must be game set and match to Boeing and Lockheed.
Sad days.

[riff_raff]

"If this post disappears I suppose it must be game set and match to Boeing and Lockheed. Sad days."

Boeing and L-M know all about the Rotodyne. And they have absolutely no interest in it.

You do realize that Boeing (McDonnell) designed, built and flew a compound rotorcraft with a tip jet driven rotor in 1954?

https://en.wikipedia.org/wiki/McDonnell_XV-1

[autogyro]

"If this post disappears I suppose it must be game set and match to Boeing and Lockheed. Sad days."

Boeing and L-M know all about the Rotodyne. And they have absolutely no interest in it.

You do realize that Boeing (McDonnell) designed, built and flew a compound rotorcraft with a tip jet driven rotor in 1954?

https://en.wikipedia.org/wiki/McDonnell_XV-1

This is an experimental aircraft based on a small fixed wing private type with a radial piston engine.
It compares badly with the Fairey Gyrodyne experimentals of the time as a poor underfunded copy but in NO way to the operational Rotodyne airliner.

Certainly McDonnell knew about the Rotodyne which is why they along with Boeing and Lockheed pushed to have all the Rotodyne airframes destroyed when their governments made a deal with the British government to destroy the British aviation industry.
Some of us still have details of this.
This is why the British bought the C130 herculese and the Chinook helicopter (Bristol Belvedere).
Rotodyne filled both roles with capability to spare.
Underhand dealing as usual.
Boeing did not want an aircraft like the Rotodyne filling all the roles of its military and civil short and medium haul aircraft and helicopters now did it.
McDonnell gained the Phantom exports to the UK to replace the TSR2 and the PROPER Lightning.
Scrapping Rotodyne also kept all the runway builders in work at the expense of the environment.
Probably the most corrupt period in capitalist history bolstered by America forcing the UK out of Suez so as to start the American Empire expansion in the middle East and North Africa that continues today as an abject failure.

The ability of the American aviation industry by comparison can be proven if you research the F35 copy of the UKs VTOL technology, yet another poor copy like America's supersonic airliner that did not work and many other covered up failures.

[Tommy Cookers]

during the 50s huge sums were GIVEN by the USA to the UK and other countries for military aircraft production and development
the Mutual Weapons Development Program
because US production could not meet its own and NATO countries huge needs consequent on the global political situation

the MWDP paid for 75% of the Pegasus engine work that gave us the Harrier

the MWDP or its forerunner also paid for all those Hunter purchases eg by Belgium and many others
these aircraft, having very poor spares and servicing backing, were replaced by US aircraft asap
Hawker repurchased them by cunning use of contractual rights and resold them worldwide (the storybook 'export success')
(Roy Braybrook did this and has written about it)
EDIT a USAF order paid 36.8 million pounds for a batch (the first ?) of RAF Gloster javelins according to Partidge's 1967 Profile book

some US airlines attempts to order Comets and Britannias were refused by their makers because timely production was beyond them

btw
according to the book 'Heelicopter' (not helicopter) by Sikorsky's mechanical designer .....
cyclic pitch variation is not necessary to a helicopter
it was a temporary fix that became permanently fixed by customer insistence

[trinidefender]

during the 50s huge sums were GIVEN by the USA to the UK and other countries for military aircraft production and development
the Mutual Weapons Development Program
because US production could not meet its own and NATO countries huge needs consequent on the global political situation

the MWDP paid for at least 50% of the Hawker P1127 aircraft work and 75% of the Pegasus engine work that gave us the Harrier

the MWDP or its forerunner also paid for all those Hunter purchases eg by Belgium and many others
these aircraft, having very poor spares and servicing backing, were replaced by US aircraft asap
Hawker repurchased them by cunning use of contractual rights and resold them worldwide (the storybook 'export success')
(Roy Braybrook did this and has written about it)

some US airlines attempts to order Comets and Britannias were refused by their makers because timely production was beyond them

btw
according to the book 'Heelicopter' (not helicopter) by Sikorsky's mechanical designer .....
cyclic pitch variation is not necessary to a helicopter
it was a temporary fix that became permanently fixed by customer insistence

If cyclic control is not needed by a helicopter then what other means do you propose to control the helicopter?

[autogyro]

Mutual Weapons Development Program
Hardly money GIVEN to the UK and other countries by the USA.
It was money to purchase weapons (the best available) for the use of NATO of which America was the main party.

Dual blade (single rotor) light autogyros and convertiplanes need neither collective or cyclic pitch control.
Teeter bearings self compensate leading and trailing blade aero requirements and tip jets set at an angle can give rotor power thrust and sufficient twist to achieve correct angle of blade incidence for all flight conditions. Mast hinging gives roll and pitch. Works perfectly.

[Tommy Cookers]

according to the book 'Heelicopter' (not helicopter) by Sikorsky's mechanical designer .....
cyclic pitch variation is not necessary to a helicopter
it was a temporary fix that became permanently fixed by customer insistence

If cyclic control is not needed by a helicopter then what other means do you propose to control the helicopter?

Sikorsky had 2 or 3 helicopter designs and prototypes and their related customers
no design had cyclic
vibration problems were found with one design, they intended to redesign (still without cyclic)
but the quick treatment was to make the rotor cyclic
and the customer (USNavy) insisted in ordering in quantity exactly as they had seen ie with cyclic
it then caught on, and Sikorsky couldn't stop it

[trinidefender]

according to the book 'Heelicopter' (not helicopter) by Sikorsky's mechanical designer .....
cyclic pitch variation is not necessary to a helicopter
it was a temporary fix that became permanently fixed by customer insistence

If cyclic control is not needed by a helicopter then what other means do you propose to control the helicopter?

Sikorsky had 2 or 3 helicopter designs and prototypes and their related customers
no design had cyclic
vibration problems were found with one design, they intended to redesign (still without cyclic)
but the quick treatment was to make the rotor cyclic
and the customer (USNavy) insisted in ordering in quantity exactly as they had seen ie with cyclic
it then caught on, and Sikorsky couldn't stop it

That still doesn't answer my question in any way. What other means can be used to control a helicopter other than using a cyclic? I.e. Cyclicly changing the blades pitch dependant on the position of the blades.

[riff_raff]

"...Certainly McDonnell knew about the Rotodyne which is why they along with Boeing and Lockheed pushed to have all the Rotodyne airframes destroyed when their governments made a deal with the British government to destroy the British aviation industry...."

You do realize that there are/were commercial jets produced by both Lockheed and Boeing that use British Rolls-Royce engines. I also hope you appreciate that the F-35B lift fan system is built by a British-owned US-based company (formerly Allison).

[autogyro]

"...Certainly McDonnell knew about the Rotodyne which is why they along with Boeing and Lockheed pushed to have all the Rotodyne airframes destroyed when their governments made a deal with the British government to destroy the British aviation industry...."

You do realize that there are/were commercial jets produced by both Lockheed and Boeing that use British Rolls-Royce engines. I also hope you appreciate that the F-35B lift fan system is built by a British-owned US-based company (formerly Allison).

Of course the 'British' companies were the first to bring jet engines into the market.
It was the corrupt British government that refused to allow a patent to control the technology and GAVE the jet engine to America and Russia.
Britain should have received thousands of billions.
During the Korean war Mig 15s and F86 Sabres fought one another with practically the same BRITISH engine design.
Speed of sound record by the Bell rocket aircraft only worked because Britain gave the design for a fully flying tail plane to them or they would still be crashing due to control reversal.
Swing wing Sir Barnes Wallis.
Its ALL British or like the American airliner podded engines German WW2.

Rolls Royce designed the 'cold' lift system for the F35B and Lockheed still has not found a manufacturer for its clutch pack.
I have consulted on it.
Rolls Royce refuse to supply their superior engine design for use in the F35 because of the huge loads placed on the forward turbine that drives this lift fan.
It restricts engine overhauls to nine vertical take offs.
This is the REAL reason why the F35B is now STOVL and not VTOL.
It was the best compromise of a bad design Lockheed could make,
By the way with low frequency radar the F35 stands out like a sore thumb, so much for the BS stealth money mine.
In fact it is a bigger signature than an Avro Vulcan.
The F35 cannot out fly an F16.

[autogyro]

That still doesn't answer my question in any way. What other means can be used to control a helicopter other than using a cyclic? I.e. Cyclicly changing the blades pitch dependant on the position of the blades.

The original concept uses a swivel joint on the rotor mast controlled with two push pull rods, one for pitch the other for roll'
The design comes from autogyro development.
Unfortunately in a powered rotor aircraft the long control rods and potential wear results in vibration.
Pantograph systems for cyclic/collective have much shorter control links directly on the blades.
Major and variable changes in rotor blade angles to achieve powered flight using collective and cyclic result in a not ideal use of the blade aerodynamics and the main design requirement is safety within the flight envelope.

A teeter bearing autogyro rotor is far more efficient if designed properly and in conjunction with the rotor head and mast mounting, it needs NO collective or cyclic control.
The Wallis AG rotor has an UNLIMITED fatigue life.

[Tommy Cookers]

Of course the 'British' companies were the first to bring jet engines into the market.
It was the corrupt British government that refused to allow a patent to control the technology and GAVE the jet engine to America and Russia.
Britain should have received thousands of billions.
During the Korean war Mig 15s and F86 Sabres fought one another with practically the same BRITISH engine design.

the Sabre of course had a GE/Allison axial flow engine that followed the RAE (Constant)/MetroVick engines given to the USA in 1944

no Whittle design engine was worth a place in a production aircraft due to his tragic adoption of reverse-flow combustion etc
(I suspect driven by re-use (to save time) of parts made for his prewar scheme that incorporated heat exchange)
tragic because reverse flow limited the compressor to a PR no better than 3

RRs takeup of Whittle work promptly replaced it with Hooker's straight-flow combustion design (Nene + smaller Derwent V)
Halford (DeHavilland) having got to straight-flow combustion earlier with the Goblin
the USSR had agreed royalty payments (eg Nene) but then decided the West was breaking political agreements

Whittle had only a weak case wrt patents
P&W (later Wright) were already paying royalties for their licensed use of specific British designs (Nene) in mass production
in this context a (rather small) blanket USA payment to the UK for general jet IPR was agreed

the Harrier (and so the F35B) would not exist without the US Marine Corps sustained enterprise
also they tried very hard with (UK built) hovercraft

and the big picture (slightly on-thread) is that an aircraft designed for a long runway will always beat the rest (eg the Comet)

EDITED
Boeing properly started the 707 after orders for 600 KC135s
the KC 135 was built eg 7000 series alloy lower wing skin to a low fatigue life, the 707 used thicker 2000 series and better life
(tanker competitors maybe assumed a better life was required, but this was not clearly demanded in official specs till later ?)
the 707 was 75% paid for by relief of penalties for WW2 excess profits (overcharging of the taxpayer)

the Viking ? and Comet used much 7000 series
fatigue was underestimated, use showed that it was liable to a rather general fatigue cracking
military aircraft eg Hercules used 7000 series