Name: fire extinguisher nozzle flow and pressure
Uploaded: 2025-02-13T15:43:18.000Z
Duration: 1 min 12 s
Channel: JoVE

소화기는 가압수를 사용하여 노즐을 통해 강력한 흐름을 생성합니다.
내부의 물은 주변 대기보다 훨씬 높은 압력으로 저장되어 소화기가 작동될 때 물이 흐르도록 합니다.
유체 역학 방정식은 물이 노즐에서 얼마나 빨리 나오고 시간이 지남에 따라 얼마나 많이 배출되는지를 결정하기 위해 적용됩니다.
첫 번째 단계는 소화기 내부와 노즐 외부의 압력 사이의 압력 차이를 이해하는 것입니다.
이 압력 차이는 물의 움직임을 주도합니다. 압력과 속도를 관련시키는 베르누이 방정식을 적용하여 노즐에서 나오는 물의 속도를 계산합니다.
노즐 직경이 작을수록 물이 떠날 때 가속되어 압력이 속도로 변환됩니다.
출구 속도를 계산한 후 유량을 결정합니다. 유속은 연속성 방정식을 사용하여 계산되며, 이는 노즐을 통해 흐르는 물의 양이 일정하도록 합니다.
유속은 물의 속도에 노즐의 단면적을 곱하여 계산됩니다.

설계 사례: 소화기를 통한 흐름

Design Example: Flow Through a Fire Extinguisher

압력수를 사용하는 소화기는 유체 역학 원리에 따라 화염을 억제할 수 있는 고속 흐름을 생성합니다. 물은 소화기 내부에서 주변 대기보다 훨씬 높은 압력으로 저장됩니다. 이 압력 차이로 인해 소화기가 작동하면 물이 빠르게 흐르게 되고, 노즐에서 물이 빠져나갈 때의 거동은 유체 역학의 기본 방정식을 사용하여 이해할 수 있습니다.

물이 어떻게 가속되는지 이해하는 열쇠는 소화기 내부와 외부 환경 사이의 압력 차이에 있습니다. 압력과 속도를 연관시키는 베르누이 방정식은 물이 노즐에서 얼마나 빨리 빠져나갈지 계산합니다.

<img alt="Equation 1" src="/files/ftp_upload/18047/18047_Equation_1.svg" style="text-align: center; height: 45px;">

이 원리에 따르면 압력이 감소함에 따라 속도가 증가합니다. 즉, 소화기 내부의 높은 내부 압력이 물이 흘러나갈 때의 속도로 변환됩니다. 물이 노즐에 접근함에 따라 노즐 직경이 감소함에 따라 흐름이 더욱 가속화되어 압력 에너지가 운동 에너지로 변환됩니다.

물의 배출 속도를 결정한 후, 유량 또는 시간에 따라 배출되는 물의 양이 계산됩니다. 계산에는 연속성 방정식이 사용되어 시스템을 흐르는 물이 일정하게 유지됩니다. 유량은 물의 속도와 노즐의 단면적의 곱입니다.

<img alt="Equation 2" src="/files/ftp_upload/18047/18047_Equation_2.svg" style="text-align: center; height: 40px;">

노즐의 직경이 작기 때문에 물이 고속으로 배출되어 화재 진압에 필요한 일관되고 강력한 흐름을 제공합니다. 이러한 원리를 적용하면 소화기의 성능을 최적화하여 효과적인 작동을 보장할 수 있습니다.

소화기는 가압수를 사용하여 노즐을 통해 강력한 흐름을 생성합니다.
내부의 물은 훨씬 더 높은 압력으로 저장됩니다 ...

design-example-flow-through-a-fire-extinguisher

Education

교육

JoVE Core

Civil Engineering

토목공학

Unit 1

제1단원

Fluid Kinematics

유체 운동학

KEY TERMS AND CONCEPTS

주요 용어 및 개념

fire extinguisher nozzle flow and pressure

A pressurized water fire extinguisher uses fluid dynamics to create a fast stream of water. The water is stored at a much higher pressure inside the extinguisher than the surrounding air. When the extinguisher is activated, that pressure difference forces water to flow out quickly.

Bernoulli's equation helps predict the exit speed of the water. This equation links pressure and velocity. As pressure drops, velocity increases. In the extinguisher, the high internal pressure is converted into the water's speed as it leaves the nozzle.

The nozzle also plays an important role because its diameter becomes smaller near the exit. A smaller opening increases the flow speed even more. This turns pressure energy into kinetic energy, which is the energy of motion.

After the exit velocity is found, the flow rate can be calculated. Flow rate is the volume of water expelled each second. The continuity equation is used to keep track of how much water moves through the system, and the flow rate equals the water speed times the nozzle's cross-sectional area. Because the nozzle is small, the water comes out at high velocity and forms a strong, steady stream for fire suppression.

Fire Extinguisher Nozzle Flow and Pressure

fire-extinguisher-nozzle-flow-and-pressure

eulerian and lagrangian flow descriptions

eulerian-and-lagrangian-flow-descriptions

Tracking Fluid Motion in Space and Time

Fluid flow can be described with the Eulerian and Lagrangian methods. These two approaches give different views of the same moving fluid. They are useful in science and engineering because the best method depends on the problem being studied. The Eulerian method looks at fixed points in space. At each location, it measures fluid properties such as velocity, pressure, and temperature as the fluid moves past. This stationary view is useful when studying how a fluid interacts with a solid object.

introduction to types of flows

Flow Patterns by Direction and Time

Fluid flow can be grouped by direction and by how it changes over time. The simplest case is one-dimensional flow. In this type, properties such as velocity and pressure change along only one axis. Water moving through a straight pipe is a common example, because changes in other directions are very small. Two-dimensional flow changes in two directions. It varies in both length and height, so the analysis is more complex than one-dimensional flow. Air moving over a flat surface, such as a...

streamlines, streaklines, and pathlines

Tracing Fluid Motion: Three Flow Paths

Streamlines, streaklines, and pathlines are three ways to describe fluid motion. Each one shows flow from a different angle. Together, they help students compare how a fluid moves in steady and unsteady flow. A streamline is a line that stays tangent to the fluid’s velocity vector at each point. That means the fluid velocity points along the streamline. Streamlines give an instant picture of the flow field, so they are useful for showing the overall direction of flow in a fluid system. In...

control volume and system representations

control-volume-and-system-representations

Tracking Fluid Through Space or Mass

Fluid analysis often uses two linked ideas: the control volume approach and the system approach. Both help describe mass, energy, and momentum transfer, but they focus on different things. One follows a region in space. The other follows a fixed mass of fluid over time. The control volume approach looks at a stationary area in space through which fluid moves. That area is bounded by a control surface, which is the outer edge of the region. A pipe with water flowing through it is a clear...

velocity and acceleration in steady and unsteady flow

velocity-and-acceleration-in-steady-and-unsteady-flow

How Flow Changes Affect Particle Motion

Velocity and acceleration help describe how a fluid particle moves in steady and unsteady flow. A fluid particle follows a pathline, and its velocity depends on both position and time. Acceleration is found by differentiating velocity with respect to time, so it shows how the particle’s motion changes. In a flow field, acceleration can be written using three perpendicular components. These components show how velocity changes over time in different spatial directions. This gives a general way...

reynolds transport theorem

Reynolds Transport and Control Volumes

Reynolds transport theorem links a fluid system to a control volume. It helps explain how the time rate of change of a property can be tracked in fluid dynamics. The theorem uses extensive properties, such as mass, velocity, acceleration, temperature, and momentum. These properties depend on the size of the system. Their intensive forms are the values per unit mass. The total amount of an extensive property in a system at any instant is the sum of the amounts carried by each tiny fluid...

design example: flow through a fire extinguisher

A pressurized water fire extinguisher uses fluid dynamics to create a fast stream of water. The water is stored at a much higher pressure inside the extinguisher than the surrounding air. When the extinguisher is activated, that pressure difference forces water to flow out quickly. Bernoulli's equation helps predict the exit speed of the water. This equation links pressure and velocity. As pressure drops, velocity increases. In the extinguisher, the high internal pressure is converted into the...

key terms and concepts

Explore how pressure, Bernoulli's equation, and nozzle size control the water speed and flow rate in a pressurized fire extinguisher.

Fire Extinguisher Nozzle Flow and Pressure | 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.

Fire Extinguisher Nozzle Flow and Pressure

Description

Transcript