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

Ciśnienie definiuje się jako wielkość siły na jednostkę powierzchni. Biorąc pod uwagę płyn nieściśliwy, siła może być wyrażona w postaci ciężaru właściwego lub gęstości płynu.
Rozważ cztery punkty w wodzie. Ciśnienie jest takie samo dla wszystkich punktów na tej samej głębokości od powierzchni, ale mniejsze na płytkich głębokościach. Ciśnienie wzrasta liniowo wraz z głębokością od powierzchni.
Zgodnie z prawem Pascala natężenie ciśnienia w dowolnym punkcie nieściśliwego płynu statycznego jest takie samo we wszystkich kierunkach.
Załóżmy, że nieskończenie mały element płynu w kształcie klina ma szerokość jednostki. Siła działająca z każdej strony jest wyrażona jako iloczyn ciśnienia i powierzchni.
Gdy ciecz jest w spoczynku, suma składowych poziomych i pionowych sił powinna wynosić zero.
Biorąc składowe poziome i stosując relacje trygonometryczne, równania są uproszczone, aby uzyskać px równe ps.
Podobnie, biorąc pod uwagę składowe pionowe, równania są uproszczone, aby uzyskać py równe ps. 
Tak więc ciśnienie w każdym punkcie jest takie samo we wszystkich kierunkach.

<ol>
	<li>Hibbeler, R.C. (2016). Mechanika inżynierska: Statyka. Czternasta edycja, New Jersey: Pearson. Strony 512.</li>
</ol>

ciśnienie płynu

W inżynierii mechanicznej ciśnienie płynu odgrywa kluczową rolę w projektowaniu systemów wykorzystujących przepływ cieczy, takich jak układy hydrauliczne, pompy i zawory. Projektując te systemy, inżynierowie muszą zapewnić, że są one w stanie wytrzymać siły wywołane przez ciśnienie płynu, aby uniknąć uszkodzeń lub awarii.

Zgodnie z prawem Pascala, płyn w spoczynku generuje równomierne ciśnienie we wszystkich kierunkach. To ciśnienie jest mierzone jako siła na jednostkę powierzchni, a jego wielkość zależy od gęstości masy płynu i głębokości punktu pomiaru od powierzchni płynu. Możemy wyrazić tę zależność matematycznie jako p = ρgz, gdzie ρ to gęstość płynu, g to przyspieszenie ziemskie, a z to głębokość.

Należy zauważyć, że powyższe równanie jest prawdziwe dla nieściskalnych płynów, czyli większości cieczy, ale nie dla gazów, których gęstość zmienia się znacząco zarówno wraz z temperaturą, jak i ciśnieniem. Aby zrozumieć, jak to równanie dotyczy cieczy, warto rozważyć trzy punkty znajdujące się wewnątrz wody. Na tej samej głębokości od powierzchni ciśnienie jest takie samo dla wszystkich trzech punktów. Jednak ciśnienie jest niższe przy płytszych głębokościach. Ciśnienie zwiększa się liniowo wraz z głębokością, gdy oddalamy się od powierzchni.

Ciśnienie płynu

W inżynierii mechanicznej ciśnienie płynu odgrywa kluczową rolę w projektowaniu systemów wykorzystujących przepływ cieczy, takich jak układy hydrauliczne, pompy i ...

Education

JoVE Core

Mechanical Engineering

Inżynieria mechaniczna

Unit 1

Jednostka 1

Center of Gravity and Centroid

Środek ciężkości i środek geometryczny

KEY TERMS AND CONCEPTS

Kluczowe terminy i pojęcia

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 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

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mechanical engineering

How Depth Changes Fluid Pressure

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