Name: bernoulli's principle in fluid devices
Uploaded: 2023-05-16T08:18:41.000Z
Duration: 1 min 17 s
Channel: JoVE

Le principe de Bernoulli a plusieurs applications pratiques, telles que les becs Bunsen, les flacons de parfum et les buses de tuyau d'incendie.
Un tube venturi est l’une de ces applications, utilisé pour mesurer la vitesse d’un fluide s’écoulant dans un tuyau.
Il se compose d’une partie convergente, la gorge, et d’une partie divergente.
Deux minces tubes verticaux sont reliés à un tube venturi, l’un avant la partie convergente et l’autre dans la région de la gorge.
Son fonctionnement est basé sur l'équation de continuité et le principe de Bernoulli.
Selon l'équation de continuité, si la section transversale du tuyau diminue, la vitesse de l'écoulement doit augmenter.
Selon le principe de Bernoulli, l'augmentation de la vitesse d'écoulement s'accompagne d'une diminution de la pression.
Ainsi, la pression près de l’entrée est élevée et la pression au centre de la région de la gorge est faible. La différence de hauteur dans le niveau de fluide dans les tubes verticaux est la mesure de la différence de pression.
Si les sections transversales sont connues, on peut résoudre ces équations pour obtenir la vitesse du fluide qui s’écoule dans le tube.

<ol>
	<li>OpenStax. (2019). Physique universitaire Vol. 1. [Version Web]. Extrait de la section 14.6, pp-719-720. <a href="https://openstax.org/books/university-physics-volume-1/pages/14-6-bernoullis-equation">https://openstax.org/books/university-physics-volume-1/pages/14-6-bernoullis-equation</a></li>
</ol>

principe de bernoulli: applications

Il existe de nombreux dispositifs et situations dans lesquels un fluide s'écoule à une hauteur constante et peut donc être analysé en utilisant le principe de Bernoulli. Ces dispositifs comprennent, entre autres, des dispositifs d'entraînement et des dispositifs de mesure de l'écoulement des fluides.

Les dispositifs d'entraînement utilisent une vitesse élevée du fluide pour créer des basses pressions et ainsi entraîner un fluide dans un autre. Voici quelques exemples de ces dispositifs :

<ol>
	<li>Un bec Bunsen utilise une buse de gaz réglable pour entraîner de l'air afin d'obtenir une combustion correcte.</li>
	<li>Un atomiseur utilise une poire d'aspiration pour créer un jet d'air qui entraîne des gouttes de parfum.</li>
	<li>Les pistolets pulvérisateurs de peinture et les carburateurs utilisent des techniques très similaires pour déplacer leurs liquides respectifs.</li>
	<li>Un aspirateur classique utilise un jet d'eau à grande vitesse pour créer une région de basse pression. Les aspirateurs peuvent être utilisés comme pompes d'aspiration dans des situations dentaires et chirurgicales, pour vider une cave inondée, ou pour réduire la pression dans un récipient.</li>
	<li>La cheminée d'un chauffe-eau est conçue pour entraîner de l'air dans le tuyau qui traverse le plafond.</li>
</ol>

Certains dispositifs utilisent le principe de Bernoulli pour mesurer la vitesse d'un fluide. Parmi ces dispositifs, on retrouve les tubes de Prandtl, également connus sous le nom de tubes de Pitot, les tubes de Venturi, et un manomètre relié à deux tubes qui sont suffisamment proches et assez petits pour ne pas perturber l'écoulement.

Principe de Bernoulli: Applications

Il existe de nombreux appareils et situations dans lesquels le fluide s'écoule à une hauteur constante et peut donc être analysé en utilisant le principe de Bernoulli. Ces appareils ...

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Bernoulli's Principle: Applications

bernoulli's principle in fluid devices

Bernoulli's principle helps explain how many fluid devices work when the fluid moves at a constant height. It is useful for devices that use fast flow to create low pressure and for devices that measure fluid speed.

Some devices use this pressure change to pull one fluid into another. These are called entrainment devices. A Bunsen burner uses an adjustable gas nozzle to entrain air for proper combustion. An atomizer uses a squeeze bulb to make a jet of air that pulls perfume drops into the flow. Paint sprayers and carburetors work in a very similar way to move their liquids.

Other examples include a common aspirator, which uses a high-speed stream of water to create a lower-pressure region. Aspirators can act as suction pumps in dental and surgical settings. They can also help drain a flooded basement or reduce the pressure in a vessel. A water heater chimney is also designed to entrain air into the pipe leading through the ceiling.

Bernoulli's principle is also used to measure fluid speed. Prandtl tubes, also called pitot tubes, Venturi tubes, and a manometer connected to two close tubes can all be used for this purpose. The tubes must be close together and small enough not to disturb the flow.

Bernoulli's Principle in Fluid Devices

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bernoulli's principle: applications

Bernoulli's principle helps explain how many fluid devices work when the fluid moves at a constant height. It is useful for devices that use fast flow to create low pressure and for devices that measure fluid speed. Some devices use this pressure change to pull one fluid into another. These are called entrainment devices. A Bunsen burner uses an adjustable gas nozzle to entrain air for proper combustion. An atomizer uses a squeeze bulb to make a jet of air that pulls perfume drops into the...

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key terms and concepts

See how Bernoulli's principle explains entrainment devices and fluid speed tools like Bunsen burners, aspirators, pitot tubes, and Venturi tubes.

Bernoulli's Principle in Fluid Devices | JoVE K12

physics

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Bernoulli's Principle in Fluid Devices

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