Skip to main content
Speclore

Open channel 流量 — manning's 方程

Manning's 方程 用于 open channel 流量, hydraulic radius 計算 與 channel 設计.

openchannelflow計算器數據表

Overview

Open channel flow is the flow of a liquid with a free surface exposed to atmospheric pressure. It occurs in rivers, canals, sewers, and partially filled pipes. The driving force is gravity, not pressure.

Key Formulas

Manning's Equation

Q=1nARh2/3S1/2Q = \frac{1}{n} A R_h^{2/3} S^{1/2}

Standard equation for open channel flow.

Froude Number

Fr=vgDhFr = \frac{v}{\sqrt{g D_h}}

Determines subcritical vs supercritical flow.

Reference Data

3
Open channel flow regime classification
Flow Regime
Froude Number
Characteristics
SubcriticalFr < 1Tranquil, slow flow; disturbances propagate upstream
CriticalFr = 1Standing waves form; minimum specific energy
SupercriticalFr > 1Rapid, shooting flow; disturbances cannot travel upstream

來源: engineeringtoolbox.com

References