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

水門は、水路内の水の流れを制御する垂直バリアです。
水門に作用する力を計算するには、水門の下を流れる水を考慮します。
力は、上流と下流の水深に依存します。
上流側では深さが z1 で、下流側では深さが z2 です。
両側の圧力差により、ゲートに正味の力が生じます。
ベルヌーイの原理を使用すると、圧力差と高さ低下に基づいて、ゲートの下の水の速度V2を計算できます。
ゲートの反力は、両側の水柱によって作用する静水力から計算されます。
ゲートが閉じているときは、圧力差が大きいため、力が大きくなります。
ゲートが開くと、ゲートの下を水が自由に流れるため、反力が減少し、正味の静水圧差が減少します。
この原理により、運転中にゲートを所定の位置に保持するために必要な固定力を決定できます。

設計例: 水門の力

Design Example: Forces in Sluice Gate

水理工学では、水門は水路、貯水池、灌漑システムを通る水の流れを管理するために不可欠です。水門は垂直の障壁として機能し、水門の開口高さを調整して水を制御します。これにより、水門の下を流れる水の速度と圧力が変わります。関連する力を理解することは、特に水門が閉じているときや部分的に開いているときに、動圧差に耐えられる水門を設計するために重要です。

 水門の力を分析する際の重要な変数には、上流の深さ z_1​ と下流の深さ z_2​ があります。水門が閉じているときは、上流側の水深が深くなり、水門全体に大きな圧力差が生じます。この圧力差によって正味の力が生じ、水門をしっかりと固定するためのアンカーシステムが必要になります。上流側にかかる静水圧は水深と重力に比例しますが、下流の圧力は z_2​ に依存します。結果として生じる水門全体の圧力勾配により、下流側に向かって水門を押し付ける正味の力が生じます。

 水門が部分的に開いている場合、水門の下を水が流れ、ベルヌーイの原理を使用して下流の速度 V_2​ を決定できます。

<img alt="Equation 1" src="/files/ftp_upload/18056/18056_Equation_1.svg" style="text-align: center; height: 90px;">

 上流と下流の深さが与えられている場合、原理は水位の差による圧力の変化を関連付け、高さの差と圧力勾配に基づいて V_2 を計算できるようにします。この流れにより、蓄積ではなく移動が可能になり、水が自由に流れるため、水門にかかる圧力が減少します。

 水門に対する総反力は、主に上流の水柱からの静水力の影響を受けます。この静水力は、水門が完全に閉じているときに最大になります。水門が開き、水がその下を流れると、圧力差が減少するため、反力が低下します。

<img alt="Equation 2" src="/files/ftp_upload/18056/18056_Equation_2.svg" style="text-align: center; height: 90px;">

水門は、水路内の水の流れを制御する垂直バリアです。
水門に作用する力を計算するには、水が水門の下を流れることを考慮します...

Education

JoVE Core

Civil Engineering

土木工学

Unit 1

ユニット1

Finite Control Volume Analysis

有限コントロールボリューム法による解析

KEY TERMS AND CONCEPTS

主要用語と概念

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.

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civil engineering

Sluice Gate Water Pressure and Reaction Force

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