Pressure theory applied to a Venturi tube

AI Thread Summary
In a Venturi tube, the pressure in the inlet and outlet is greater than in the throat due to the principles of Bernoulli's equation, which describes the conservation of energy in fluid dynamics. As the fluid flows into the narrower section of the tube, its speed increases, resulting in higher kinetic energy density and lower pressure. This relationship illustrates that pressure is inversely related to fluid velocity in a confined space. Understanding this concept is essential for self-learning about fluid mechanics. The discussion emphasizes the importance of energy conservation in explaining pressure variations within the tube.
extricate
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Hi,

I'm a little confused about the pressure in the inlet/outlet and the throat of a Venturi tube.

Why is the pressure in the inlet/outlet greater than in the throat? I thought that because air is needed to flow into a smaller space so the pressure has to be greater?

Pardon me. I've self-learning.

Thanks for your time.
 
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welcome to pf!

hi extricate! welcome to pf! :smile:

it's conservation of energy (density) …

Bernoulli's equation is simply a conservation of energy (density) equation

(and pressure is energy density: pressure = work done per displaced volume = energy per displaced volume)

where the tube is narrower, the speed is faster, so the kinetic energy density is greater

so the pressure must be less :wink:
 
Thanks a lot for the reply.
 

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