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

가장자리 치수가 정의된 작은 삼각형 쐐기를 임의의 위치에 있는 유체 덩어리에서 추출하는 것을 고려하십시오.
쐐기에 작용하는 유일한 힘은 주변 유체가 평평한 표면에 가하는 수직 압력과 유체 요소 자체의 무게입니다.
전단 응력을 고려하지 않고 가속 운동을 경험한다고 가정된 유체 요소에 대한 y 및 z 방향의 운동 방정식은 0과 같습니다.
압력에 의해 생성된 힘을 계산하기 위해 작용하는 면적을 곱합니다.
수직 및 수평 치수는 기하학적 관계를 기반으로 하는 경사면의 길이로 표현할 수 있습니다.
이러한 값을 운동 방정식에 대입하면 삼각형 쐐기의 평면에 작용하는 힘에 대한 표현이 형상에 관련된 측면의 길이로 단순화됩니다.
길이가 0에 가까워지면 결과는 유체 내의 각 표면에서 작용하는 압력이 서로 같다는 것을 나타냅니다. 이 중요한 발견을 파스칼의 법칙이라고 합니다.

지점에서의 압력 개념

유체 내 지점에서의 압력 개념은 유체 내 압력이 특정 위치에서 모든 방향으로 균일하다는 것을 확립합니다. 이러한 균일성은 유체 분자가 유체 내에서 무작위 운동과 지속적인 충돌로 인해 모든 지점에 균일하게 힘을 가하기 때문에 발생합니다. 지점에서의 압력은 주변 유체 분자에 의해 결정되며 모양이나 방향보다는 깊이와 밀도와 같은 요인의 영향을 받습니다.

정지 상태의 유체에서 압력은 방향과 무관한 분자 상호 작용으로 인해 모든 방향으로 동일하게 작용합니다. 유체 내 깊이가 증가함에 따라 압력은 비례적으로 상승하는데, 이는 특정 지점에서의 압력이 해당 지점 위의 유체 기둥 높이와 유체 밀도에만 의존한다는 원리를 따릅니다. 이는 파스칼의 법칙으로 이어지며, 이는 비압축성 유체의 한 지점에서 압력이 변하면 유체의 모든 지점에 동일하게 전달된다는 것을 주장합니다.

균일한 압력 분포의 이러한 기본 원리는 토목 공학 응용 분야에서 매우 중요합니다. 예를 들어, 댐을 설계할 때는 다양한 깊이에서 물이 가하는 압력을 신중하게 고려해야 합니다. 압력은 깊이에 따라 증가하고 댐의 구조적 무결성에 영향을 미치기 때문입니다.

가장자리 치수가 정의된 작은 삼각형 쐐기를 임의의 위치에 있는 유체 덩어리에서 추출하는 것을 고려하십시오.
쐐기에 작용하는 유일한 힘은 ...

Education

교육

JoVE Core

Civil Engineering

토목공학

Unit 1

제1단원

Fluid Statics

유체 정역학

KEY TERMS AND CONCEPTS

주요 용어 및 개념

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 offers a foundational exploration of essential construction materials such as bricks, stones, steel, wood, and concrete, along with fluid mechanics topics like flow over immersed bodies, open channel flow, and dimensional modeling. It also covers key surveying concepts, including leveling, traverse adjustments, curve design, topographic mapping, and geospatial technologies (GPS & GIS). Science-in-action videos showcase laboratory research on materials, fluids, and surveying practices in real-world engineering systems.

civil engineering

Fluid Pressure at One Point

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