Name: centrifugal pump flow rate calculation
Uploaded: 2025-02-13T15:43:22.000Z
Duration: 1 min 4 s
Channel: JoVE

אם יש לחשב את קצב הזרימה של משאבה צנטריפוגלית המפעילה לחץ של 7500 ג'אול לשנייה כדי להרים מים ממאגר במפלס נמוך יותר למאגר במפלס עליון, ניתן להשתמש במשוואת האנרגיה.
הפרש המפלס בין המאגרים הוא 10 מטרים, ואובדן הראש הוא 5 מטרים.
מכיוון שפני השטח של שני המאגרים פתוחים לאטמוספירה, הלחץ והמהירות הן בכניסה והן במוצא הם אפס, מה שמפשט עוד יותר את משוואת האנרגיה.
כאן, ראש המשאבה מתקבל על ידי המנה של קלט כוח פיר נטו ואת המוצר של משקל היחידה של המים ואת קצב הזרימה.
אם ראש המשאבה מוחלף במשוואת האנרגיה הפשוטה, ניתן לקבל את קצב הזרימה של המשאבה.
יתר על כן, החלפת הערכים הניתנים בביטוי לקצב הזרימה נותנת את הערך הסופי המציין את קצב שאיבת המים.

יישום משוואת האנרגיה

<div style="direction:rtl">יישום משוואת האנרגיה למשאבות צנטריפוגליות הוא עיקרון יסוד בדינמיקת נוזלים ובהנדסה. במקרה זה, משוואת האנרגיה משמשת לחישוב קצב הזרימה של משאבה צנטריפוגלית, האחראית על העברת מים בין שני מאגרים בגבהים שונים. המשאבה מספקת אנרגיה בהספק של 7500 ג׳ול לשנייה, והפרש הגובה האנכי בין המאגר התחתון לעליון הוא 10 מטרים. בנוסף, אובדן הגובה עקב חיכוך והתנגדויות אחרות הוא 5 מטרים. פרמטרים אלו חיוניים לפתרון קצב הזרימה באמצעות משוואת האנרגיה. מכיוון ששני המאגרים פתוחים לאטמוספירה, הלחץ בנקודות הכניסה והיציאה של המשאבה שווה ללחץ האטמוספרי. עובדה זו מאפשרת לבטל את איברי הלחץ במשוואת האנרגיה. יתרה מכך, מכיוון שהמהירות בנקודות הכניסה והיציאה זניחות, גם איברי המהירות במשוואה מתבטלים. לכן, משוואת האנרגיה עבור מקרה זה תלויה רק בגובה הכבידה ובגובה שמספקת המשאבה. הגובה המיוצר על ידי המשאבה מחושב על ידי חלוקת הספק הציר נטו במכפלת קצב הזרימה במשקל הסגולי של המים. הצבת גובה זה במשוואת האנרגיה ופתרון עבור קצב הזרימה של המשאבה מאפשרים לקבוע את הערך המבוקש.</div>

אם קצב הזרימה של משאבה צנטריפוגלית המפעילה לחץ של 7500 ג'אול לשנייה כדי להרים מים ממאגר במפלס נמוך יותר למאגר ב ...

Education

JoVE Core

Civil Engineering

הנדסה אזרחית

Unit 1

יחידה 1

Finite Control Volume Analysis

ניתוח נפח בקרה סופי

KEY TERMS AND CONCEPTS

מונחים ומושגים מרכזיים

Application of the Energy Equation

centrifugal pump flow rate calculation

Centrifugal pump flow rate can be calculated with the energy equation. In this problem, water moves between two reservoirs at different elevations, and the pump provides the energy needed for the transfer. The pump input is 7500 joules per second, the elevation difference is 10 meters, and the head loss from friction and other resistances is 5 meters.

Both reservoirs are open to the atmosphere, so the pressure at the inlet and outlet is the same. That means the pressure terms in the energy equation cancel. The flow at the inlet and outlet is also negligible, so the velocity terms drop out as well.

With pressure and velocity terms removed, the equation depends on the gravitational head and the pump head. The pump head is found by dividing the net shaft power input by the product of the flow rate and the specific weight of water. Substituting that head into the energy equation makes it possible to solve for the pump flow rate.

Centrifugal Pump Flow Rate Calculation

conservation of mass in finite cotrol volume

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Continuity Equation for a Fixed Control Volume

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conservation of mass in fixed, nondeforming control volume

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Continuity and Velocity in Pipe Flow

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conservation of mass in moving, nondeforming control volume

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Stormwater Detention Basin Mass Balance

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linear momentum in control volume

Momentum Balance for Fluid Control Volumes

Linear momentum balance for a fluid control volume links Newton’s second law to moving fluid. The law says that the rate of change of linear momentum equals the sum of the external forces acting on the system. In a fluid system, this idea helps explain how motion and force are related. A control volume can match the fluid system at a specific moment. When that happens, the forces on the control volume and the system are the same. Reynolds transport theorem explains this connection by splitting...

application of the linear momentum equation

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Forces in a 180° Pipe Bend

Forces in a 180-degree pipe bend can be found by applying the linear momentum equation to flowing water. The pipe has a constant cross-sectional area of 0.01 square meters, and the water moves at 15 meters per second. The pressure at the inlet is 0.2 megapascals, and the pressure at the outlet is 0.16 megapascals. The goal is to find the force components in the x and y directions that hold the bend in place. In this case, the flow is only in the y direction at both the entrance and the exit.

moment-of-momentum equation

Wind Turbine Torque and Angular Momentum

The moment-of-momentum equation helps explain how wind turbine blades create torque. Torque is the turning effect of a force around an axis. In rotating systems, this equation links the motion of the wind with the force acting on it. The equation begins with Newton's second law for a fluid particle. That law says the rate of change of linear momentum equals the external force on the particle. To find torque, the position of the particle relative to the rotation axis is combined with that force.

conservation of energy in control volume

Turbine Work from Energy Changes

A turbine can turn fluid energy into shaft work when flow passes through a control volume. The fluid enters the turbine at one point and leaves at another. Under steady-flow conditions, there is no energy buildup inside the control volume, so the stored energy does not change with time. This steady-flow setup makes the energy equation simpler. The turbine is treated as doing mechanical work, and heat transfer is taken as negligible, so Q̇ is approximately zero. The flow at the inlet and outlet...

application of the energy equation

Centrifugal pump flow rate can be calculated with the energy equation. In this problem, water moves between two reservoirs at different elevations, and the pump provides the energy needed for the transfer. The pump input is 7500 joules per second, the elevation difference is 10 meters, and the head loss from friction and other resistances is 5 meters. Both reservoirs are open to the atmosphere, so the pressure at the inlet and outlet is the same. That means the pressure terms in the energy...

design example: forces in sluice gate

Sluice Gate Water Pressure and Reaction Force

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key terms and concepts

Use the energy equation to find the flow rate of a centrifugal pump lifting water between reservoirs. Includes elevation change, head loss, and pump head.

Centrifugal Pump Flow Rate Calculation | 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

Centrifugal Pump Flow Rate Calculation

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