Name: hydrostatic pressure and fluid depth
Uploaded: 2025-02-13T15:43:11.000Z
Duration: 1 min 11 s
Channel: JoVE

Considere un pequeño elemento fluido en reposo. La aceleración del fluido es cero, y la ecuación general del movimiento se simplifica en consecuencia.
En estas condiciones, solo el componente vertical tiene una fuerza que actúa sobre el fluido.
Si las presiones en diferentes niveles de fluido varían, la integración de los componentes de fuerza vertical da la diferencia de presión entre los dos niveles.
Si la distancia entre dos niveles es h, la diferencia de presión se puede expresar en términos de h.
Aquí, h se denomina carga de presión, que indica la presión en el punto inferior debido al fluido en la región entre el punto inferior y el punto superior.
Si se supone que la referencia superior es la superficie del agua, entonces la presión en la superficie es frecuentemente la presión atmosférica.
Luego, la presión a cualquier profundidad h por debajo de la superficie del fluido se expresa en términos de la presión atmosférica.
Esto indica que para un fluido en reposo, la presión en cualquier punto debajo de la superficie depende de la profundidad y la presión atmosférica que actúa en la superficie.

variación de presión en un fluido en reposo

En un fluido en reposo, la presión en cualquier punto debajo de la superficie del fluido depende únicamente de la profundidad, no de la forma o el tamaño del recipiente. Este principio, conocido como presión hidrostática, surge porque, en fluidos estacionarios, no hay aceleración, lo que significa que las fuerzas dentro del fluido se equilibran. Solo las fuerzas verticales, causadas por el peso del fluido que se encuentra sobre él, contribuyen a los cambios de presión con la profundidad. Al medir la presión en dos niveles diferentes dentro del fluido, la diferencia de presión se debe al peso del fluido entre estos puntos. Esta diferencia se puede expresar en términos de carga de presión, un concepto que vincula la profundidad del fluido con la presión que ejerce. La carga de presión es directamente proporcional a la distancia vertical o profundidad entre dos puntos. Cuanto más profundo sea el punto dentro del fluido, mayor será la presión debido al peso del fluido que se encuentra sobre él. Si la superficie del fluido es el punto de referencia, donde la presión suele ser la atmosférica, entonces la presión a cualquier profundidad debajo de la superficie es igual a la presión atmosférica más la presión adicional ejercida por el fluido sobre ese punto. Esta relación es la base de muchas aplicaciones prácticas, como la comprensión de las presiones submarinas, la determinación de la presión del agua en tanques y el diseño de estructuras para soportar las fuerzas de los fluidos.

Variación de presión en un fluido en reposo

Considere un pequeño elemento fluido en reposo. La aceleración del fluido es cero, y la ecuación general del movimiento se simplifica en consecuencia.
En estas condiciones, ...

Education

Educación

JoVE Core

Civil Engineering

Ingeniería Civil

Unit 1

Unidad 1

Fluid Statics

Estática de Fluidos

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

Pressure Variation in a Fluid at Rest

hydrostatic pressure and fluid depth

Hydrostatic pressure describes how pressure changes with depth in a fluid at rest. In a stationary fluid, the fluid acceleration is zero, so the forces inside the fluid balance. That means pressure at a point below the surface depends on depth, not on the container’s shape or size.

Only vertical forces affect the pressure change in this situation. These forces come from the weight of the fluid above a point. When pressure is compared at two different levels, the difference in pressure equals the weight of the fluid between those points.

This pressure difference is often described using pressure head. Pressure head is the vertical distance, or depth, between two points in the fluid. It shows that pressure is directly proportional to depth. The deeper the point, the greater the pressure from the fluid above it.

If the fluid surface is used as the reference point, the pressure there is often atmospheric pressure. The pressure at any depth below that surface equals atmospheric pressure plus the extra pressure from the fluid above. This relationship helps explain underwater pressure, water pressure in tanks, and the forces that fluid can place on structures.

Hydrostatic Pressure and Fluid Depth

concept of pressure at a point

Fluid Pressure at One Point

Fluid pressure at one point is the focus of this lesson. It shows that pressure in a fluid is the same in every direction at a single location. This happens because fluid molecules move randomly and collide with nearby molecules in a balanced way. At a given point, the pressure depends on the surrounding fluid molecules. It is affected by depth and density, not by the shape of the container or the way the fluid is oriented. In a fluid at rest, the pressure acts equally in all directions...

basic equation for pressure field

Pressure Balance in a Fluid Element

The pressure field equation describes how forces stay balanced inside a small fluid element. In fluid mechanics, this balance helps explain how pressure changes from one place to another within a fluid. Two main force types act on a fluid segment: surface forces and body forces. Surface forces come from pressure differences across nearby points in the fluid, so they depend on the local pressure gradient, which is the rate of pressure change with position. Body forces are spread through the...

pressure variation in a fluid at rest

Hydrostatic pressure describes how pressure changes with depth in a fluid at rest. In a stationary fluid, the fluid acceleration is zero, so the forces inside the fluid balance. That means pressure at a point below the surface depends on depth, not on the container’s shape or size. Only vertical forces affect the pressure change in this situation. These forces come from the weight of the fluid above a point. When pressure is compared at two different levels, the difference in pressure equals...

measurement of fluid pressure

Manometers and Gauges for Fluid Pressure

Fluid pressure is measured with manometers and related gauges. These tools use a liquid column to show pressure differences. The height of the column gives a simple reading of the force the fluid exerts. A basic manometer is the piezometer. It is a vertical tube that is open at the top and filled with the same fluid being measured. When the tube connects to a container, the fluid height in the tube matches the pressure inside that container. For more detailed measurements, the U-tube...

hydrostatic pressure force on a plane surface

hydrostatic-pressure-force-on-a-plane-surface

Hydrostatic Pressure on Submerged Surfaces

Hydrostatic pressure creates force on submerged plane surfaces. The force depends on the fluid pressure and the area of the surface. The way that force acts changes with the surface position. For a horizontal surface, the depth stays the same across the whole area. That means the pressure is uniform. The resultant force equals the pressure at that depth multiplied by the surface area, and it acts through the centroid of the surface. For a vertical surface, pressure increases as depth...

hydrostatic pressure force on a curved surface

hydrostatic-pressure-force-on-a-curved-surface

Finding the Force on Curved Fluid Surfaces

Hydrostatic pressure on curved surfaces is an important idea in fluid mechanics. It helps explain how water pushes on curved structures in civil engineering. Examples include reservoirs, dams, and storage tanks. The pressure changes in both size and direction along the curve. To find the total hydrostatic force on a curved surface, engineers isolate the fluid volume next to that surface. They then study the forces on imaginary horizontal and vertical planes that cut through the volume. The...

buoyancy and stability for submerged and floating bodies

buoyancy-and-stability-for-submerged-and-floating-bodies

How Buoyancy Keeps Bodies Stable in Water

Buoyancy and stability explain how submerged and floating bodies behave in a fluid. When a body is fully or partly under water and stays still, the fluid pushes upward on it. That upward push is called the buoyant force. The buoyant force acts through the center of buoyancy. This is the center of the displaced fluid volume. Archimedes’ principle says the buoyant force equals the weight of the fluid displaced by the body. Stability describes whether a body can return to its original position...

design example: application of archimedes' principle

design-example-application-of-archimedes-principle

Floating Block Buoyancy and Center of Buoyancy

Archimedes' principle is used to analyze the buoyant force on a wooden block that floats in seawater. The block has a rectangular section, and its dimensions, specific gravity, and the specific weight of seawater are used in the calculation. This setup shows how floating bodies stay in equilibrium. The first step is to find the weight of the block from its volume and specific gravity. Then Archimedes' principle is applied. The weight of the displaced water must equal the weight of the block.

key terms and concepts

Learn how hydrostatic pressure changes with depth in a fluid at rest, why container shape does not matter, and how pressure head links depth to pressure.

Hydrostatic Pressure and Fluid Depth | JoVE K12

JoVE Core Civil Engineering provides a foundational exploration of essential construction materials in civil engineering, focusing on bricks, stones, steel, wood, and concrete through easy-to-understand animated videos. This collection covers the properties, manufacturing processes, and practical applications of these materials. Additionally, the accompanied science-in-action videos demonstrate the research experiments performed in laboratories.

civil engineering

Hydrostatic Pressure and Fluid Depth

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