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

A pressão é definida como a magnitude da força por unidade de área. Considerando um fluido incompressível, a força pode ser expressa em termos de peso específico ou densidade do fluido.
Considere quatro pontos na água. A pressão é a mesma para todos os pontos na mesma profundidade da superfície, mas menor em profundidades rasas. A pressão aumenta linearmente com a profundidade da superfície.
De acordo com a lei de Pascal, a intensidade da pressão em qualquer ponto de um fluido estático incompressível é a mesma em todas as direções.
Suponha um elemento fluido infinitesimal em forma de cunha de largura unitária. A força de cada lado é expressa como o produto da pressão e da área.
Como o líquido está em repouso, a soma dos componentes horizontal e vertical das forças deve ser zero.
Tomando os componentes horizontais e usando relações trigonométricas, as equações são simplificadas para obter px igual a ps.
Da mesma forma, considerando os componentes verticais, as equações são simplificadas para obter py igual a ps. 
Portanto, a pressão em qualquer ponto é a mesma em todas as direções.

<ol>
	<li>Hibbeler, R.C. (2016). Engenharia Mecânica: Estática. Décima quarta edição, Nova Jersey: Pearson. Pág. 512.</li>
</ol>

pressão dos fluidos

Em engenharia mecânica, a pressão dos fluidos desempenha um papel crítico no projeto de sistemas que utilizam fluxo de líquido, como sistemas hidráulicos, bombas e válvulas. Ao projetar esses sistemas, os engenheiros devem garantir que eles possam suportar as forças criadas pela pressão dos fluidos, a fim de evitar danos ou falhas.

De acordo com a lei de Pascal, um fluido em repouso gerará pressão igual em todas as direções. Essa pressão é medida como uma força por unidade de área, e sua magnitude depende do peso específico ou densidade de massa do fluido e da profundidade do ponto de medição a partir da superfície do fluido. Podemos expressar essa relação matematicamente como p = ρgz, onde ρ é a densidade do fluido, g é a aceleração devida à gravidade e z é a profundidade.

Deve-se notar que a equação, mencionada acima, é válida para fluidos incompressíveis, como a maioria dos líquidos, mas não para gases, cuja densidade varia consideravelmente com a temperatura e pressão. Para entender como essa equação se aplica aos líquidos, considere três pontos localizados dentro da água. Na mesma profundidade da superfície, a pressão é idêntica para os três pontos. No entanto, a pressão é mais baixa em profundidades rasas. A pressão aumenta linearmente com a profundidade à medida que nos afastamos da superfície.

Pressão dos Fluidos

Na engenharia mecânica, a pressão do fluido desempenha um papel crítico no projeto de sistemas que utilizam fluxo de líquido, como sistemas hidráulicos, bombas e ...

Education

JoVE Core

Mechanical Engineering

Engenharia Mecânica

Unit 1

Unidade 1

Center of Gravity and Centroid

Centro de Gravidade e Centroide

KEY TERMS AND CONCEPTS

TERMOS-CHAVE E CONCEITOS

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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