Name: sluice gate water pressure and reaction force
Uploaded: 2025-02-13T15:43:22.000Z
Duration: 1 min 11 s
Channel: JoVE

Una paratoia è una barriera verticale che controlla il flusso d'acqua in un canale.
Per calcolare le forze che agiscono su una paratoia, si consideri l'acqua che scorre sotto la paratoia.
Le forze dipendono dalle profondità dell'acqua a monte e a valle.
Sul lato a monte, la profondità è z1 e sul lato a valle la profondità è z2.
La differenza di pressione tra i due lati crea una forza netta sul cancello.
Utilizzando il principio di Bernoulli, la velocità dell'acqua sotto la paratoia, V2, può essere calcolata in base alla differenza di pressione e alla caduta di altezza.
La forza di reazione sul cancello è calcolata dalla forza idrostatica che agisce a causa della colonna d'acqua su entrambi i lati.
La forza è maggiore quando il cancello è chiuso a causa della maggiore differenza di pressione.
Quando il cancello viene aperto, la forza di reazione diminuisce man mano che l'acqua scorre liberamente sotto il cancello, riducendo la differenza di pressione idrostatica netta.
Questo principio consente di determinare la forza di ancoraggio necessaria per mantenere il cancello in posizione durante il funzionamento.

esempio di progettazione: forze in una paratoia

Design Example: Forces in Sluice Gate

Nell'ingegneria idraulica, le paratoie sono essenziali per gestire il flusso d'acqua attraverso canali, bacini e sistemi di irrigazione. Le paratoie, che agiscono come barriere verticali, regolano l'acqua modificando l'altezza di apertura della paratoia, che modifica la velocità e la pressione dell'acqua che scorre sotto la paratoia. Comprendere le forze coinvolte, è fondamentale per progettare paratoie in grado di resistere a differenze di pressione dinamiche, soprattutto quando la paratoia è chiusa o parzialmente aperta.

Le variabili chiave nell'analisi delle forze della paratoia, includono la profondità a monte z_1​ e la profondità a valle z_2​. Quando la paratoia è chiusa, la profondità dell'acqua è maggiore sul lato a monte, creando una significativa differenza di pressione attraverso la paratoia. Questa differenza di pressione produce una forza netta, che richiede un sistema di ancoraggio per mantenere la paratoia saldamente in posizione. La pressione idrostatica esercitata sul lato a monte, è proporzionale alla profondità dell'acqua e alla forza gravitazionale, mentre la pressione a valle dipende da z_2​. Il gradiente di pressione risultante attraverso la paratoia, crea una forza netta che spinge contro di essa verso il lato a valle.

Quando la paratoia è parzialmente aperta, l'acqua scorre sotto di essa e può essere utilizzato il principio di Bernoulli, per determinare la velocità a valle, V_2​.

<img alt="Equation 1" src="/files/ftp_upload/18056/18056_Equation_1.svg" style="text-align: center; height: 90px;">

Date le profondità a monte e a valle, il principio mette in relazione la variazione di pressione dovuta alle differenze di altezza dell'acqua, consentendo di calcolare V_2 in base alle differenze di altezza e ai gradienti di pressione. Questo flusso riduce la pressione esercitata sulla paratoia, consentendo il movimento anziché l'accumulo, riducendo la forza netta mentre l'acqua scorre liberamente.

La forza di reazione totale sulla paratoia, è influenzata principalmente dalla forza idrostatica della colonna d'acqua a monte, che è al massimo quando la paratoia è completamente chiusa. Quando la paratoia si apre e l'acqua scorre sotto di essa, la riduzione della differenza di pressione, abbassa la forza di reazione.

<img alt="Equation 2" src="/files/ftp_upload/18056/18056_Equation_2.svg" style="text-align: center; height: 90px;">

Esempio di Progettazione: Forze in una Paratoia

Una paratoia è una barriera verticale che controlla il flusso d'acqua in un canale.
Per calcolare le forze che agiscono su una paratoia, si consideri l'acqua che scorre sotto ...

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Finite Control Volume Analysis

Analisi a volume di controllo finito

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sluice gate water pressure and reaction force

Sluice gates control water flow in channels, reservoirs, and irrigation systems. They work as vertical barriers with an opening that can be raised or lowered. Changing the opening height changes the water velocity and pressure below the gate.

The forces on a sluice gate depend on the water depths upstream and downstream, written as z1 and z2. When the gate is closed, the upstream water depth is greater. That creates a strong pressure difference across the gate and a net force toward the downstream side. In that case, the gate needs an anchoring system to keep it secure.

The pressure on the upstream side is hydrostatic pressure, which depends on water depth and gravity. The downstream pressure depends on z2. Together, these pressures create the pressure gradient that pushes on the gate.

When the sluice gate is partially open, water flows beneath it. Bernoulli's principle can then be used to find the downstream velocity, V2, from the upstream and downstream depths. As the water moves through the opening instead of building up, the pressure difference becomes smaller and the reaction force on the gate decreases. The total reaction force is therefore highest when the gate is fully closed and lower as the gate opens.

Sluice Gate Water Pressure and Reaction Force

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design example: forces in sluice gate

Sluice gates control water flow in channels, reservoirs, and irrigation systems. They work as vertical barriers with an opening that can be raised or lowered. Changing the opening height changes the water velocity and pressure below the gate. The forces on a sluice gate depend on the water depths upstream and downstream, written as z1 and z2. When the gate is closed, the upstream water depth is greater. That creates a strong pressure difference across the gate and a net force toward the...

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Learn how upstream and downstream water depths affect pressure, flow speed, and reaction force on a sluice gate when it is closed or partially open.

Sluice Gate Water Pressure and Reaction Force | 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.

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Sluice Gate Water Pressure and Reaction Force

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