Coanda design question

[PALG]

Hello

I have been a lurker here for quite some time and thought i should join as there is so much know-how on this site.

I have had an interest in Henri Coanda for some time and benefitted greatly from the occassional discussions about him and his designs on this site.

I now have a question to which i cannot find the answer anywhere else.

Coanda's early penchant for the cruciform tail-plane design was evident in hie early designs - 1910, 1911 and (I think, from the only image of it i have seen) his 1913 pusher canard concept.

As far as i know, the only design with this tail that flew was the Coanda 1911.

Did this crucifom tail-plane design work? If so, what were its advantages and shortcomings ?

I presume it was not a a great success as it was never pursued in mainstream airframe design and he did not apparently try to incorporate it into any of his Bristol designs.

Is there any information out there about this ?

I have a secondary question also. from time to time i have seen references here to a publication by a Romanian author about ROmanian aviation history, which is printed in English. Where might it be possible to purchase a copy and how comprehensive is the information on Coanda and his designs ? I have the great article in the French magazine Avions No 157. even thouigh I cannot read French, i can see there are some great images of the SIA COanda 1916 and I would like to find more info about his work.

[Varese2002]

Hi PALG, welcome at the Forum Aerodrome. You present an interesting question, which could better be positioned in the Pre-1914 section of the Forum , which is located in the No man's land part of the Forum - subdivision Pioneer aviation.

Henri Coanda was one of the brilliant designers working in 1910 - 1912 in Paris after which he left for the English Bristol firm as chief designer. In his name quite a lot of patents are registered, some of which depict the 'Coanda tail'. The pro's and con's of this tail configuration could have been described in these patents. I will have a look at it.

The book you are referring to is

Antoniu, Dan and George Cicos. Romanian aeronautical constructions. ISBN 973-567-523-4

More on this book and how to order it can be found here

The part of the book covering the work of Coanda covers pages 20 - 39. That's about his complete lifetime achievements. Looking through it I could not find very much about the cruciform empennage design of Coanda, although there is an interesting detail picture.

The 1913 Coanda Monoplane Canard of 1913 was never manufactured. There is a patent for this tandem-wing monoplane canard (actually the propeller was about in the midst of the fuselage !). The machine had a more conventional rudder not the cruciform empannage.

Cheers

Kees

[PALG]

Thankyou very much for your reply Kees. I look forward to any info you might find in the patents. Even apart from whether the tail design was a success or not, i'd love to know the theory of how it was supposed to work.

thankyou for the pointer about the appropriate place to post future such queries, and also especially for the information about the Romanian book.

A followup question if i may about the 1913 design. Are there any other blueprints or other schematics out there of this design ? It would eb great to see how such an early canard design might have worked, especially with what appears to be a form of winglets. The only image I have ever seen is this:

[Varese2002]

Originally Posted by PALG

A followup question if i may about the 1913 design. Are there any other blueprints or other schematics out there of this design ? It would be great to see how such an early canard design might have worked, especially with what appears to be a form of winglets. The only image I have ever seen is this:

The image shows the wind tunnel model of the Coanda Monoplane Canard 1913. This model model was used for wind tunnel tests in the wind tunnel of Gustave Eiffel. As I wrote the design was a tandem-wing monoplane. It was very, very advanced for 1913.

The machine is described in a British patent of 1912 No.29,401 Improvements in or relating to Aeroplanes. You can clearly see the fuselage and the place the propeller was designed in the midst of the fuselage.

Thinking about the wind tunnel tests of Eiffel (the engineer of the famous tower of course), these were all published pro year, so you can probably see the results of those tests in the volume of 1911 or 1912.

I have attached the Coanda patent of 1912 No.29,401.

Cheers

Kees

[Varese2002]

I found out the (1914) work of Eiffel which presumably gives the results of the wind tunnel tests of the Coanda Monoplane Canard 1913. Sure copies of this 2-volume work are very rare and fetch high prices (think in a 1000 - 1500 Euro ). But perhaps a library can deliver the pages about the Coanda. Remember, text is in French of course.

EIFFEL , GUSTAV. Nouvelles recherches sur la résistance de l'air et l'aviation faites au laboratoire d'Auteuil / par G. Eiffel. Paris, H. Dunod et E. Pinat, 1914. viii, 406, p. front ( helioengraving., 266 illustrations/, tables, diagrs) and atlas (viii, 67 p., 1 l. XXXIX pl. (part /large folding) 32 cm. 4to. 2 volumes.

This is the description of Eiffel's different experiments with scale models in his wind-tunnel at d 'Auteuil. Eiffel was one of the pioneer engineers using a wind tunnel in aeronautics.The following air planes were described and drawn in scale in the atlas.: L'aeroplane laboratoir du Cdant Dorand; Monoplan Drzewiecki (Type Canard); Monoplan du Lieutenant Blard; Monoplan Blériot ( type Militaire); Biplan Miliatire M. Farman; Biplan Bréquet; Monoplan Morane - Saulner; Monoplan paris; LÁéro-Torpille no 4 Tatin. ; Monoplan Bristol; Monoplan Lettellier-Bruneau; L'hydroaéroplane Jeanson-Colliex; L'Hydroaéroplane Bréquet; L'hydroaéroplane Nieuport; L'hydroaéroplane Pateras Pescara.; L'hydroaéroplane de mm. Alvarez et de Condé; L'hydroaéroplane Oertz; etc...

Cheers

Kees

[PALG]

Thanks Kees, for your really generous help – both the patent and your other references. The patent was a real pleasure to look at it – what an amazing and forward-thinking design. There appear to have been some minor adjustments to the design when the wind tunnel model was made, not least the addition of the winglets and possibly some re-arranging of the wings – on the model, there appear to be struts between the two wings. Anyway, a really rich resource, thankyou for providing it.

I realise now I have seen that great photo of Eiffel next to his wind tunnel – the one where he stands with the model of Tatin’s and Paulhan’s Aero-Torpille, which is my other favourite pioneer design. Its clear that once the Aero-Torpille came out, Coanda took to it immediately. I imagine it appealed very much to his passion for streamlining and efficient manipulation of airflow. What a perfect blending of concepts and ideas, then, in Coanda’s later designs !

I am not sure I will ever be able to access the volumes you refer to, here in AUstralia in hardcopy form, thought there may just be one or two universities who have them, such as Monash UNiversity. I may pursue some Europan libraries online.

thanks again ! If you find anything further I'd be most interested.

[Varese2002]

Returning to the tail configuration of Coanda, much information is in patents taken out by Henri Coanda in France, Germany and Great Britain.

The configuration of the tail is described by Coanda as a Saint Andrew's Cross. The idea behind was -

A new and improved means for the control of aeroplanes wherein are arranged and combined a rudder having vanes and the configuration of whose successive cross-sections gradually approaches the form of a Saint Andrew's Cross; wings; manually operated means for warping the wings; foot-levers and means operated thereby to swing or bend the rudder-vanes upwards or downwards, said means being also capable of being manually operated to move the rudder-vanes to the left or right.

In an aeroplane a rudder having vanes wherin the configuration of the successive cross-sections of said rudder and vanes from the front to rear gradually approaches the form of a Saint Andrew's Cross, the said vanes being capable of being swung or flexed either simultanuously with or independently of the warping of the wings, in combination with means for affecting such swinging or flexing.

I have attached an English and German patent of Coanda, which are incidentally different. The English one has much more detail of the whole controlling mechanismus of an aeroplane.

Cheers

Kees

[PALG]

Thankyou again Kees - I'm getting far more resources than I thought were even available !

I cant seem to open the English one, it 'contains an error'.

So far, everywhere I have looked, there doesnt seem to be any evaluation of the design in flight, that I have seen. The Coanda Twin 1911 actually flew, did it not ? was there any analysis arising out of that ?

I'd really appreciate any opinions on what people might consider the strengths/weaknesses of such a tail design. It wasnt taken up in any kind of significant way, so either it was not suitable - for example - in combat conditions, or it was unecessarily complex to manufacture and master ...so many questions.

I am assuming it must have flight characteristics in common with V-tail designs (such as the much later Mystere jet), and that must have worked well-enough...

Any opinions out there would be more informed than mine.

I am not sure if this thread should be moved or not to Pioneer Aviation, as suggested earlier, but I understand if it has to be.

[SCMc]

The English version opened without problem for me. I was able to view 11 of 11 pages.

Steve

[Varese2002]

No problems with the English patent here, it loads all 11 pages correctly, probably computer gremlins.

About the success of the St. Andrews tail one can only speculate, but it is a fact that the 1911 twin-engined Coanda machine was not very successfull in the Reims Millitary Concours of 1911.

Given the difference from ordinary tails (rudders / elevators) it might be that the military brass was not very enthusiastic about these experiments and would not have it in the army. That's - if the client don't want it, it will not sell. So the St. Andrews Cross tail construction became history.

A few snippets of Coanda -

• He was scientific and methodical, this is a picture of the wind tunnel model for the Eiffel soufflerie ('wind tunnel') for the 1910 Coanda biplane (note differences in the model)

• Coanda patented almost all of his inventions as far as I can see, also the engine construction of the 1911 machine, which drove a single a double irscrew

AFAIK nothing was seen after the 1910/1911 invention of Coanda of the St. Andrew's Cross tail construction.

Cheers

Kees