WING LIFT THEORY SHAKEN – LA THÉORIE DE LA PORTANCE DE L’AILE ÉBRANLÉE

I had already written about that in my book UNE AUTRE HISTOIRE DE L’AVIATION, on pages 12; 13; 71; and others – Bernoulli’s principle does not explain everything. We know that aircraft fly. Strange as it may seem, Bernoulli’s principle has often been taught for decades as the explanation of the phenomenon.

Je l’avais déjà évoqué dans mon livre « Une autre histoire de l’aviation » aux pages 12, 13, 71, et d’autres: Le théorème de Bernoulli n’explique pas tout. Nous savons que les avions volent. Depuis des décennies, aussi bizarre que cela puisse paraître, on enseigne souvent le théorème de Bernoulli comme l’explication principale au phénomène.

This explanation would make sense if the air particles split at the leading edge of the wing and come together at the trailing edge. However, Cambridge researchers had debunked this flying myth in 2012, and have recently confirmed that Bernoulli’s principle cannot explain everything in wing lift. As you can see on the video above, the upper wing air stream travels much faster than the lower wing one. Last but not least, these air streams do not come together at the trailing edge since the upper wing air stream reaches the trailing edge well before the lower wing airflow. Isn’t this amazing?

Cette explication tiendrait si les particules d’air se séparaient au bord d’attaque de l’aile et se rejoignaient au bord de fuite. Cependant, des chercheurs de Cambridge avaient démonté ce mythe du vol en 2012 et viennent de confirmer que le principe de de Bernoulli ne peut pas tout expliquer dans la portance de l’aile. Comme vous pouvez le voir sur la vidéo ci-dessus, le flux d’air en extrados voyage beaucoup plus vite que celui d’intrados. Enfin et surtout, ces flux d’air ne se rejoignent pas au bord de fuite puisque le flux d’air d’extrados atteint le bord de fuite bien avant le flux d’intrados. Étonnant, n’est-ce pas?

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FLIGHT RADIOTELEPHONY VARIANTS

GREAT VIDEO – Watch for pleasure, first. Listen carefully to the figures and phrases uttered and compare with the various texts that are enforced in the world, and in Europe. In such an extreme situation, you may understand that the procedures are turned into a faster phraseology. So, why not adopt it in GAT (General Air Traffic), after all? 😉

SUPERBE VIDÉO: Regardez d’abord pour le plaisir. Écoutez attentivement les chiffres et expressions et comparez les avec les textes en vigueur dans le monde et en Europe. Dans une situation aussi extrême, on peut comprendre que les procédures se fassent plus rapidement dans la phraséologie. Alors pourquoi ne pas l’adopter dans la CAG (Circulation Aérienne Générale), après tout? 😉

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CHINESE J-31 STEALTH FIGHTER AIRCRAFT

The brand new 5th-generation fighterjet Shenyang J-31 – or F60, which would be nicknamed Gyrfalcon – took off on October 31, 2012. She thus performed a test flight – probably her maiden flight – on Wednesday.

This futuristic PLAAF (People’s Liberation Army Air Force) stealth multirole jetfighter looks like an F-35 Lightning II though the Gyrfalcon (or Falcon Eagle?) turns out to be a twin-engine a/c. She would be more maneuverable but smaller than the latest Chengdu J-20 Black Eagle stealth fighter. Her radar cross section (RCS) might be very small, and stealthier than recent 5th-generation fighter aircraft as the radome mounting looks as if it were – like the rest of the airframe – designed with reentrant shapes.

This fighter aircraft would not exceed Mach 2, and she features a DSI (Diverterless Supersonic Inlet) so that the airspeed can be reduced while entering the air intake, thus preventing the engine from breaking up.

Here are a few pictures, and videos:

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Mach-3 SR-71 Blackbird’s HOT COCKPIT

Blackbird onboard USS Intrepid – Photo © Xavier Cotton http://www.passionpourlaviation.fr

As you may have heard, the mythical Lockheed SR-71 Blackbird was a strategic reconnaissance aircraft able to fly at more than Mach 3 – Mach 3.3 ie around 3,500 km/h; or 1,900 kts; and at a maximum flight level of… FL 850 or 26 kilometers high!

The Blackbird indeed had a unique flight envelope with a particular doghouse plot (since she could not exceed 3.5 G), and an exceptionnal coffin corner limited by her CIT – Compressor Inlet Temperature of 427°C maximum.

This aircraft was also unique for her engines were two J58 ramjets fuelled by JP-7 especially refined for extreme flying purpose. This special fuel could drip and leak abundantly as the airframe made up of titanium was retracted while taxiing, and became airtight only when it got its operating shape while flying very fast and very high because of the air density, and surrounding pressure plus the heating caused by the air friction at such speeds. In short, the whole structure considerably expanded when airborne.

The irony – I heard it on the grapevine, or read it somewhere on the web – that titanium which turned into dark blue while flying (SR-71s probably deserved those unofficial other nicknames « Bluebird », or « Habu » viper) was « imported » from… USSR!

Pilots must have taken significant risks inherent in flying such an aircraft as mentioned in this previous post. These pilots used to fly over the USSR to take strategic reconnaissance photographs during the Cold war. They wore pressurized spacesuits so that their blood could not boil in case of decompression or ejection at such altitudes.

The Blackbird travelled faster than a rifle bullet, and the air friction could have melt aluminum-skinned aircraft. At Mach 3.2, fuel cycled behind the chine surface in order to cool the aircraft! The inner windshield temperature could reach 120°C even though a heavy-duty cooling system was on a full function. On landing, the outside temperature of the canopy could reach 300°C, and it must have been far beyond on the fuselage, and wing surfaces while flying at high speeds. The pilot could feel the heat behind his protective gloves!

Special thanks to Xavier Cotton for the Blackbird photos. Please, visit his website on http://www.passionpourlaviation.fr

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SKYDIVER Felix BAUMGARTNER’s TOP 5 JUMPS

Felix Baumgartner, the famous Austrian skydiver, is still waiting for better meteorological conditions to make a new attempt in the Red Bull Stratos project to break the sound barrier while freefalling. This new feat might happen within the next few days as it has already been scheduled on October 14.

According to the video below, Felix BAUMGARTNER’s top 5 jumps are:

  1. Wingsuit Channel Crossing
  2. Taipei 101 BASE Jump
  3. Petronas Towers BASE Jump
  4. Seating of the Spirits Cave Jump
  5. Man vs. Plane

 


Felix BAUMGARTNER was to jump on the 9th of October 2012. However, this jump which could have become the highest skydive in the aerospace history has been put off due to gusty winds.

In this new record attempt Felix BAUMGARTNER will be so high up – 120,000 ft, or 36.6 km – that if his suit leaks, his blood will boil. When he jumps, he will fall so fast that he will break the sound barrier as explained in this video:

 

 

A 3-hour ascent is expected to reach such an altitude, and it could take him more than a quarter of an hour to fall down back to the earth, and land… And now the animation on how it could unfold from the stratosphere right over Roswell, New Mexico, USA: (Click on the link below – MUST SEE!)

 

http://www.redbullstratos.com/gallery/?mediaId=media1859674064001

 

 

GO FELIX!

 

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