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

Wenn die Fördermenge einer Kreiselpumpe, die mit einem Druck von 7500 Joule pro Sekunde Wasser von einem Reservoir auf einer unteren Ebene in ein Reservoir auf einer oberen Ebene befördert, berechnet werden muss, kann die Energiegleichung verwendet werden.
Der Pegelunterschied zwischen den Reservoirs beträgt 10 Meter und der Druckverlust 5 Meter.
Da die Oberflächen beider Reservoirs zur Atmosphäre hin offen sind, sind der Druck und die Geschwindigkeit sowohl im Einlass als auch im Auslass Null, was die Energiegleichung weiter vereinfacht.
Dabei ergibt sich die Förderhöhe der Pumpe aus dem Quotienten aus der Netto-Wellenleistungsaufnahme und dem Produkt aus dem Stückgewicht des Wassers und der Fördermenge.
Wenn die vereinfachte Energiegleichung durch die Förderhöhe der Pumpe ersetzt wird, kann die Fördermenge der Pumpe ermittelt werden.
Des Weiteren ergibt das Einsetzen der in dem Ausdruck angegebenen Werte für die Durchflussrate den endgültigen Wert, der die Geschwindigkeit angibt, mit der das Wasser gepumpt wird.

anwendung der energiegleichung

Die Anwendung der Energiegleichung auf Kreiselpumpen ist ein grundlegendes Prinzip der Strömungsdynamik und des Ingenieurwesens. In diesem Szenario wird die Energiegleichung verwendet, um die Durchflussrate einer Kreiselpumpe zu berechnen, die für die Übertragung von Wasser zwischen zwei Reservoirs auf unterschiedlichen Höhen zuständig ist. Die Pumpe wendet eine Energiezufuhr von 7500 Joule pro Sekunde an, und der Höhenunterschied zwischen dem unteren und oberen Reservoir beträgt 10 Meter. Darüber hinaus beträgt der Druckverlust durch Reibung und andere Widerstände 5 Meter. Diese Parameter sind für die Berechnung der Durchflussrate mithilfe der Energiegleichung von entscheidender Bedeutung.

Da beide Reservoirs zur Atmosphäre hin offen sind, entspricht der Druck am Einlass und Auslass der Pumpe dem atmosphärischen Druck. Dadurch können sich die Druckterme in der Energiegleichung aufheben. Da außerdem die Geschwindigkeiten am Einlass und Auslass vernachlässigbar sind, werden auch die Geschwindigkeitsterme in der Gleichung eliminiert. Die Energiegleichung für diesen speziellen Fall hängt nur von der Gravitationshöhe und der Pumpenhöhe ab.

Die von der Pumpe erzeugte Förderhöhe wird ermittelt, indem die Nettowellenleistung durch das Produkt aus Durchflussrate und spezifischem Gewicht des Wassers geteilt wird. Durch Einsetzen dieser Förderhöhe in die Energiegleichung und Auflösen kann die Durchflussrate der Pumpe ermittelt werden.

Anwendung der Energiegleichung

Wenn die Durchflussmenge einer Kreiselpumpe, die einen Druck von 7500 Joule pro Sekunde anwendet, um Wasser aus einem Behälter auf einem niedrigeren Niveau in einen Behälter mit einem ...

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JoVE Core

Civil Engineering

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Unit 1

Einheit 1

Finite Control Volume Analysis

Finite-Kontrollvolumen-Analyse

KEY TERMS AND CONCEPTS

WICHTIGE BEGRIFFE UND KONZEPTE

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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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...

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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

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civil engineering

Centrifugal Pump Flow Rate Calculation

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