Name: fluid pressure at one point
Uploaded: 2025-02-13T15:43:11.000Z
Duration: 1 min 15 s
Channel: JoVE

Considere la posibilidad de extraer una pequeña cuña triangular con dimensiones de borde definidas de una masa de fluido en una ubicación arbitraria.
Las únicas fuerzas que actúan sobre la cuña son las fuerzas de presión normales ejercidas por el fluido circundante sobre las superficies planas y el peso del propio elemento fluido.
Las ecuaciones de movimiento en las direcciones y y z para el elemento fluido que se supone que experimenta un movimiento acelerado sin considerar las tensiones de cizallamiento son iguales a cero.
La presión se multiplica por el área sobre la que actúa para calcular la fuerza generada por la presión.
Las dimensiones vertical y horizontal se pueden expresar en términos de la longitud del plano inclinado en función de las relaciones geométricas.
Al sustituir estos valores en las ecuaciones de movimiento, las expresiones de las fuerzas que actúan sobre los planos de la cuña triangular se simplifican en términos de las longitudes de los lados involucrados en la geometría.
Si las longitudes se acercan a cero, el resultado indica que la presión que actúa en cada superficie dentro del fluido es igual entre sí. Este hallazgo clave se conoce como la ley de Pascal.

concepto de presión en un punto

El concepto de presión en un punto de un fluido establece que la presión dentro de un fluido es uniforme en todas las direcciones en una ubicación específica. Esta uniformidad se produce porque las moléculas del fluido ejercen fuerza de manera uniforme en cualquier punto debido a su movimiento aleatorio y a las colisiones continuas dentro del fluido. La presión en un punto está determinada por las moléculas del fluido circundante y está influenciada por factores como la profundidad y la densidad, en lugar de la forma o la orientación. En un fluido en reposo, la presión actúa de manera igual en todas las direcciones debido a interacciones moleculares que son independientes de la dirección. A medida que aumenta la profundidad dentro del fluido, la presión aumenta proporcionalmente, siguiendo el principio de que la presión en un punto específico depende únicamente de la altura de la columna de fluido por encima de ese punto y de la densidad del fluido. Esto conduce a la ley de Pascal, que afirma que cualquier cambio en la presión en un punto en un fluido incompresible se transmite de manera igual a todos los puntos del fluido. Este principio fundamental de distribución uniforme de la presión es crucial en aplicaciones de ingeniería civil. Por ejemplo, al diseñar presas, se debe considerar cuidadosamente la presión ejercida por el agua a diferentes profundidades, ya que la presión aumenta con la profundidad e impacta la integridad estructural de la presa.

Concepto de presión en un punto

Considere la posibilidad de extraer una pequeña cuña triangular con dimensiones de borde definidas de una masa de fluido en una ubicación arbitraria.
Las únicas fuerzas que actúan sobre la cuña ...

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

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 because the molecular motion does not favor one direction over another.

Pressure also increases as depth increases. The pressure at a specific point depends on the height of the fluid column above that point and on the fluid’s density. This idea leads to Pascal’s law, which says that a pressure change at one point in an incompressible fluid is transmitted equally throughout the fluid.

This principle is important in civil engineering. When engineers design dams, they must account for water pressure at different depths. Water pressure rises with depth, and that increase affects the dam’s structural strength.

Fluid Pressure at One Point

concept of pressure at a 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 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...

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

Explore how fluid pressure acts at a single point, why it is equal in all directions, and how depth, density, and Pascal’s law apply to dams.

Fluid Pressure at One Point | 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

Fluid Pressure at One Point

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