B Hydrodynamics Effects: Are They the Same?

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The discussion clarifies that the Coanda effect and ram pressure are distinct hydrodynamic phenomena. The Coanda effect involves fluid flow parallel to a surface, remaining attached due to viscosity and boundary layer velocity variations. In contrast, ram pressure arises from perpendicular flow creating pressure due to unbalanced kinetic energy. Observations of a hose nozzle being "sucked in" during an experiment relate to the Bernoulli effect, where fluid velocity beneath the nozzle exceeds that above it. Understanding these principles is crucial for accurately explaining observed fluid dynamics.
dom_quixote
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Are these hydrodynamic effects the same?

 
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No, they are different effects.
Coanda effect; https://en.wikipedia.org/wiki/Coandă_effect
Ram pressure; https://en.wikipedia.org/wiki/Ram_pressure

In one, the flow is parallel to the surface and remains attached due to fluid viscosity and the velocity variation in the boundary layer.

In the other, the flow is perpendicular and provides a pressure due to unbalanced kinetic energy; KE = ½·m·v² .

Maybe you are seeing some other phenomenon. You need to explain the process you are referring to, or observing, in each case.
 
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Thanks Baluncore!

mang.JPG

I did a variation of the second experiment with a bucket. I did not film the experiment due to the difficulty of observing the phenomenon. However, the hose nozzle is also "sucked in" even when the water level rises. Would it be the same effect "RAM Pressure"?
 
dom_quixote said:
I did a variation of the second experiment with a bucket. I did not film the experiment due to the difficulty of observing the phenomenon. However, the hose nozzle is also "sucked in" even when the water level rises. Would it be the same effect "RAM Pressure"?
Then, for the second part of the video you were referring to the sucking effect between hose end and flat lid.
This happens because the Bernoulli effect, as the fluid velocity under the hose nozzle is greater than the one above.

Please, see:
https://en.wikipedia.org/wiki/Bernoulli's_principle

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