Name: how depth changes fluid pressure
Uploaded: 2023-09-22T11:49:33.000Z
Duration: 1 min 14 s
Channel: JoVE

La pressione è definita come l'entità della forza per unità di area. Considerando un fluido incomprimibile, la forza può essere espressa in termini di peso specifico o densità del fluido.
Considera quattro punti in acqua. La pressione è la stessa per tutti i punti alla stessa profondità dalla superficie, ma minore a basse profondità. La pressione aumenta linearmente con la profondità dalla superficie.
Secondo la legge di Pascal, l'intensità della pressione in un dato punto in un fluido statico incomprimibile è la stessa in tutte le direzioni.
Supponiamo un elemento fluido infinitesimale a forma di cuneo di larghezza unitaria. La forza su ciascun lato è espressa come il prodotto della pressione e dell'area.
Poiché il liquido è a riposo, la somma delle componenti orizzontali e verticali delle forze dovrebbe essere zero.
Prendendo le componenti orizzontali e utilizzando le relazioni trigonometriche, le equazioni vengono semplificate per ottenere px uguale a ps.
Allo stesso modo, considerando le componenti verticali, le equazioni vengono semplificate per ottenere py uguale a ps. 
Quindi, la pressione in qualsiasi punto è la stessa in tutte le direzioni.

<ol>
	<li>Hibbeler, R.C. (2016). Ingegneria Meccanica: Statica. Quattordicesima edizione, New Jersey: Pearson. Pagine 512.</li>
</ol>

pressione dei fluidi

Nell'ingegneria meccanica, la pressione dei fluidi svolge un ruolo cruciale nella progettazione di sistemi che utilizzano il flusso di liquidi, come i sistemi idraulici, le pompe e le valvole. Quando si progettano questi sistemi, gli ingegneri devono assicurarsi che possano resistere alle forze create dalla pressione dei fluidi per evitare danni o guasti.

Secondo il principio di Pascal, un fluido in quiete genera una pressione uguale in tutte le direzioni. Questa pressione viene misurata come una forza per unità di area e la sua grandezza dipende dal peso specifico del fluido o dalla densità di massa e dalla profondità del punto di misurazione dalla superficie del fluido. Possiamo esprimere questa relazione matematicamente come p = ρgz, dove ρ è la densità del fluido, g è l'accelerazione di gravità e z è la profondità.

Va notato che l'equazione, come menzionato sopra, è valida per i fluidi incomprimibili, come la maggior parte dei liquidi, ma non per i gas, la cui densità cambia considerevolmente sia con la temperatura che con la pressione. Per capire come questa equazione si applica ai liquidi, consideriamo tre punti situati all'interno dell'acqua. Alla stessa profondità dalla superficie, la pressione è uguale per tutti e tre i punti. Tuttavia, la pressione è più bassa alle basse profondità. La pressione aumenta linearmente con la profondità mano a mano che ci si allontana dalla superficie.

Pressione dei fluidi

Nell'ingegneria meccanica, la pressione del fluido svolge un ruolo fondamentale nella progettazione di sistemi che utilizzano il flusso del liquido, come sistemi idraulici, pompe e ...

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Center of Gravity and Centroid

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KEY TERMS AND CONCEPTS

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Fluid Pressure

how depth changes fluid pressure

Fluid pressure changes with depth in liquids used in engineering systems. It matters in hydraulic systems, pumps, and valves, where the forces from moving and resting fluid must be considered to prevent damage or failure.

For a fluid at rest, Pascal’s law says the pressure is equal in all directions. Pressure is force per unit area. Its size depends on the fluid’s specific weight, or mass density, and on how deep the measurement point is below the fluid surface.

This relationship can be written as p = ρgz. In this equation, ρ is fluid density, g is the acceleration due to gravity, and z is depth. The equation applies to incompressible fluids, such as most liquids, but not to gases, because gas density can change greatly with temperature and pressure.

The pattern is easy to see in water. If three points are at the same depth, their pressure is the same. A point closer to the surface has lower pressure. As depth increases, pressure rises in a linear way.

How Depth Changes Fluid Pressure

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fluid pressure

Fluid pressure changes with depth in liquids used in engineering systems. It matters in hydraulic systems, pumps, and valves, where the forces from moving and resting fluid must be considered to prevent damage or failure. For a fluid at rest, Pascal’s law says the pressure is equal in all directions. Pressure is force per unit area. Its size depends on the fluid’s specific weight, or mass density, and on how deep the measurement point is below the fluid surface. This relationship can be...

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key terms and concepts

Explore how fluid pressure changes with depth, why Pascal’s law matters, and how the equation p = ρgz describes pressure in liquids like water.

How Depth Changes Fluid Pressure | JoVE K12

JoVE Core Mechanical Engineering offers concise, easy-to-understand animated videos covering key topics such as equilibrium, forces, truss analysis, and structural mechanics. Explore their real-world applications, and witness these concepts in action through scientist-led experiments.

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How Depth Changes Fluid Pressure

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