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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SOLUTIONS TO SAVE JET FUEL

NASA Langley Research Center in Hampton, Virginia – New energy-efficient airplanes could be designed. Researchers work on designs for viable commercial aircraft which could leave a low to zero carbon footprint.

In order to save jet fuel, they look at new concepts, processes, and designs that could be lighter. They try to reduce drag, and they try to increase the propulsive efficiency. For this purpose, they try to get rid of metallic airframes, and parts as often as possible.

For instance NASA has a newer composite 10 percent lighter than carbon fiber composite. This advanced material is called « Pultruded rod stitched efficient unitized structure » or PRSEUS.

The new sleeker designs look like large wings without any traditional tube-shaped fuselage in the central part since it is blended with the wings. These futuristic designs are more fuel efficient as the more lift the plane has, the less it consumes fuel.

The researchers also look at new energy sources as it is showed in this video, and in the end there is further information about the NextGen project which could save fuel too, thanks to this new form of air traffic management:

 

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Volcanic ash posing a threat to flight safety

Sunday 5/22/2011 – Breaking news:

The Grimsvötn volcano began erupting yesterday. It is located underneath the uninhabited Vatnajokull glacier in southeastern Iceland. As it has been sending ash into the skies up to flight level 650 i.e. 65,000 ft or around 20 kilometers or 12 miles.

The European fleets might be grounded due to the spreading of an ash cloud which is forecast to drift over Scotland on Tuesday – May 24, 2011 – and expected to reach France and Spain by Thursday or Friday. Here is an interesting short documentary about how the scientists examine the volcanic ash, and how they determine that it can pose a threat to aircraft.

Watch the video:

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Russian forces crackdown on pirates off Somali coast

RIA Novosti courtesy

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NASA tests on X-48B blended wing body

Click on the picture below to watch the video:

Boeing X-48B Blended wing body - NASA photo / Tony Landis
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