Name: venturi meter flow rate from pressure
Uploaded: 2026-01-30T03:08:31.000Z
Duration: 1 min 16 s
Channel: JoVE

벤투리 계량기는 폐수 유량을 측정하기 위해 하수 시스템에 설치됩니다. 유속이 알려져 있고 점성 효과가 무시할 수 있는 경우 유량계에 부착된 압력계에 표시된 압력 차이는 무엇입니까?
먼저, 각각의 직경을 사용하여 파이프와 목구멍의 단면적을 계산합니다.
그런 다음 연속성 방정식을 사용하여 주어진 유속을 기반으로 두 섹션의 속도를 결정합니다.
면적과 속도는 반비례하기 때문에 폐수는 직경이 큰 파이프에서 작은 목구멍으로 이동함에 따라 속도가 빨라집니다.
다음으로, 흐름의 두 점 사이의 압력 차이를 속도 변화와 관련시키는 베르누이 방정식을 적용합니다.
이 방정식은 물이 더 큰 파이프에서 더 작은 목구멍으로 이동할 때 속도가 증가함에 따라 해당 압력 강하가 있음을 보여줍니다.
마지막으로, 속도를 베르누이 방정식에 대입하여 파이프와 목 사이의 압력 차이를 계산합니다.
유량계에 부착된 압력계는 최종 압력 차이를 나타냅니다.

베르누이 방정식-문제 해결

벤투리 미터는 파이프라인에서 유체 유량을 측정하는 데 필수적입니다. 베르누이 방정식에서 설명하는 유체 속도와 압력 간의 관계를 활용합니다. 하수 시스템에 설치하면 벤투리 미터는 압력 차이를 측정하여 폐수 유량을 정확하게 결정합니다.

첫 번째 단계는 파이프와 벤투리 목의 단면적을 계산하여 압력 게이지에서 표시된 압력 차이를 분석하는 것입니다. 다음으로 연속 방정식을 적용하는데, 이는 비압축성 유체의 경우 체적 유량(Q)이 파이프라인을 따라 일정하게 유지된다는 것을 나타냅니다.

<img alt="Equation 1" src="/files/ftp_upload/18035/18035_Equation_1.svg" style="text-align: center; height: 12px;">

A_1과 A_2는 파이프와 목의 단면적이고 V_1과 V_2는 이러한 구간에서의 유체 속도입니다. 방정식을 재배열하면 목구멍의 속도는 다음과 같이 표현할 수 있습니다.

<img alt="Equation 2" src="/files/ftp_upload/18035/18035_Equation_2.svg" style="text-align: center; height: 30px;">

따라서 주어진 유량에 대해 속도 V_1과 V_2를 계산할 수 있습니다.

베르누이 방정식은 이상적인 유체의 압력과 속도를 다음과 같이 나타냅니다.

<img alt="Equation 3" src="/files/ftp_upload/18035/18035_Equation_3.svg" style="text-align: center; height: 27px;">

여기서 P_1과 P_2는 파이프와 목구멍의 압력이고 ⍴는 유체의 밀도입니다. 압력 차이(P_1 - P_2)는 속도 V_1과 V_2를 이 방정식에 대입하여 계산할 수 있습니다. 압력 게이지로 표시된 이 압력 강하(ΔP)는 폐수가 좁은 목구멍을 통과할 때 속도가 증가함을 반영하며, 이는 에너지 보존과 일치합니다.

벤투리 계량기는 폐수 유량을 측정하기 위해 하수 시스템에 설치됩니다. 유속이 알려져 있고 점성 효과가 무시할 수 있다면 무엇입니까 ...

Education

교육

JoVE Core

Civil Engineering

토목공학

Unit 1

제1단원

Fluid Dynamics

유체역학

KEY TERMS AND CONCEPTS

주요 용어 및 개념

Bernoulli's Equation: Problem Solving

venturi meter flow rate from pressure

A Venturi meter measures fluid flow rate in a pipeline by using pressure changes and Bernoulli's equation. In a sewage system, it can be used to determine wastewater flow rate by reading the pressure difference across the meter. The narrowed throat makes the fluid speed up, and that change in speed is linked to pressure drop.

The first step is to find the cross-sectional areas of the pipe and the Venturi throat. These areas are needed to interpret the pressure difference shown on the pressure gauge. Next, the continuity equation is applied. For an incompressible fluid, the volumetric flow rate Q stays constant, and the pipe and throat areas are written as A1 and A2 with velocities V1 and V2.

From the continuity equation, the throat velocity can be rearranged and calculated from the flow rate. Once V1 and V2 are known, Bernoulli's equation is used to relate pressure and velocity in an ideal fluid. With the fluid density included, the pressures P1 and P2 in the pipe and throat can be compared to find the pressure difference.

Substituting the velocities into Bernoulli's equation gives the pressure drop, ΔP. That pressure drop is the value indicated by the pressure gauge. It reflects the increase in fluid speed as wastewater moves through the narrower throat, which follows energy conservation.

Venturi Meter Flow Rate from Pressure

bernoulli's equation for flow along a streamline

bernoulli-s-equation-for-flow-along-a-streamline

Pressure and Speed in Bernoulli's Equation

Bernoulli's equation links pressure, speed, and height in a moving fluid along a streamline. It is used for incompressible, inviscid fluids under steady flow. The idea comes from applying Newton's second law to a small fluid element. That element feels forces from pressure differences, gravity, and changes in velocity. The resulting equation shows how fluid energy is shared. In the equation, P is pressure, ρ is fluid density, v is velocity, g is the acceleration due to gravity, and h is...

bernoulli's equation for flow normal to a streamline

bernoulli-s-equation-for-flow-normal-to-a-streamline

Pressure Changes Across Curved Streamlines

Bernoulli's equation for flow normal to a streamline describes how pressure changes across curved streamlines. When a fluid follows a curved path, the outer side of the curve experiences centrifugal force, which pushes the fluid outward. The pressure is therefore higher on the inner side, near the center of curvature, and lower farther out. The size of this pressure difference depends on the fluid's velocity and the radius of curvature. In flows with nearly straight streamlines, the pressure...

bernoulli's equation: problem solving

A Venturi meter measures fluid flow rate in a pipeline by using pressure changes and Bernoulli's equation. In a sewage system, it can be used to determine wastewater flow rate by reading the pressure difference across the meter. The narrowed throat makes the fluid speed up, and that change in speed is linked to pressure drop. The first step is to find the cross-sectional areas of the pipe and the Venturi throat. These areas are needed to interpret the pressure difference shown on the pressure...

static, stagnation, dynamic and total pressure

static-stagnation-dynamic-and-total-pressure

Pitot-Static Measurement in Bernoulli Flow

Static pressure, dynamic pressure, stagnation pressure, and total pressure are key ideas in fluid dynamics. They are often explained with Bernoulli's equation. In that equation, p is static pressure, 1/2ρV^2 is dynamic pressure, γz is hydrostatic pressure or potential energy pressure, and pT is total pressure. For incompressible flow, the total pressure stays constant along a streamline. Static pressure is the pressure a fluid exerts when it is at rest, or when flowing fluid is brought to rest...

free jet

Liquid Speed from Reservoir Outlets

Free jets show how liquid moves after leaving a reservoir through an opening and flowing into the air without resistance. The jet speed is found with Bernoulli’s principle, and it depends on the height of liquid above the opening. This relationship assumes atmospheric pressure at both the reservoir surface and the jet exit. The liquid column’s height controls the speed at the nozzle because the fluid’s potential energy changes into kinetic energy during flow. As the liquid leaves the...

continuity equation

Fluid Flow and Area Changes

Fluid flow and area changes are linked by the continuity equation. For a steady flow of an incompressible fluid in a confined system, the mass flow rate stays constant. This idea is useful in nozzles, syringes, and pipes where the cross-sectional area changes. The mass flow rate is written as an equation that connects density, area, and velocity. For incompressible flow, the density stays the same, so the equation becomes simpler. When the area gets smaller, the fluid speed must increase. When...

energy line and hydraulic gradient line

Fluid Head Profiles in Pipes and Channels

Fluid head profiles in pipes and channels show how pressure, speed, and height change in a flowing fluid. These profiles come from Bernoulli's equation for steady, incompressible, inviscid flow. In that equation, total head includes pressure head, velocity head, and elevation head. The energy line (EL) shows the total head available in the flow. It sits above the datum and includes all three energy parts. Under ideal conditions, the EL stays horizontal because the total energy does not change...

design example: designing water slide

Water Slide Speed and Bernoulli's Principle

Water slide speed is controlled by Bernoulli's principle and the height of the slide. Engineers use these ideas to keep the ride exciting while making sure the water stays safe for riders. As water moves downhill, gravity makes it speed up. The water at the bottom depends on the height it starts from. A taller slide gives the water more potential energy at the top. That energy changes into kinetic energy as the water descends, so the flow becomes faster. Bernoulli's principle helps describe...

key terms and concepts

See how a Venturi meter uses continuity and Bernoulli's equation to turn pressure differences into wastewater flow rate in a sewage system.

Venturi Meter Flow Rate from 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.

civil engineering

Venturi Meter Flow Rate from Pressure

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