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

정지해 있는 작은 유체 요소를 생각해 보십시오. 유체 가속도는 0이고 그에 따라 운동의 일반 방정식이 단순화됩니다.
이러한 조건에서는 수직 구성 요소만 유체에 작용하는 힘을 갖습니다.
서로 다른 유체 수준의 압력이 변하는 경우 수직 힘 구성 요소를 통합하면 두 수준 간의 압력 차이가 발생합니다.
두 수준 사이의 거리가 h이면 압력 차이는 h로 나타낼 수 있습니다.
여기서, h는 압력수(pressure head)라고 불리며, 이는 하한점과 상부점 사이의 영역에서 유체로 인한 하한점에서의 압력을 나타낸다.
상단 참조가 물의 표면이라고 가정하면 표면의 압력은 종종 대기압입니다.
그런 다음 유체 표면 아래의 모든 깊이 h에서의 압력은 대기압으로 표현됩니다.
이는 정지 상태인 유체의 경우 표면 아래 지점의 압력이 깊이와 표면에 작용하는 대기압에 따라 달라진다는 것을 나타냅니다.

정지 상태의 유체에서 압력 변화

정지 상태의 유체에서 유체 표면 아래의 모든 지점의 압력은 용기의 모양이나 크기가 아닌 깊이에만 의존합니다. 정수압이라고 알려진 이 원리는 정지 유체에서는 가속도가 없기 때문에 유체 내부의 힘이 균형을 이룹니다. 위에 있는 유체의 무게로 인해 발생하는 수직력만이 깊이에 따른 압력 변화에 기여합니다.

유체 내의 두 가지 다른 수준에서 압력을 측정할 때 압력 차이는 이러한 지점 사이의 유체 무게 때문입니다. 이 차이는 압력 수두로 표현할 수 있는데, 이는 유체의 깊이와 유체가 가하는 압력을 연결하는 개념입니다. 압력 수두는 두 지점 사이의 수직 거리 또는 깊이에 직접 비례합니다. 유체 내의 지점이 깊을수록 그 위에 있는 유체의 무게로 인해 압력이 커집니다.

유체 표면이 기준점인 경우(압력은 종종 대기압임) 표면 아래의 모든 깊이에서 압력은 대기압과 해당 지점 위의 유체가 가하는 추가 압력과 같습니다. 이러한 관계는 수중 압력 이해, 탱크 내 수압 결정, 유체력을 견딜 수 있는 구조물 설계 등 여러 가지 실제 응용 분야의 기초가 됩니다.

정지해 있는 작은 유체 요소를 생각해 보십시오. 유체 가속도는 0이고 그에 따라 운동의 일반 방정식이 단순화됩니다.
이러한 조건에서 ...

Education

교육

JoVE Core

Civil Engineering

토목공학

Unit 1

제1단원

Fluid Statics

유체 정역학

KEY TERMS AND CONCEPTS

주요 용어 및 개념

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 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

Hydrostatic Pressure and Fluid Depth

Description

Transcript