How much water can a canal, ditch, or storm drain carry? Set the geometry and slope and Manning's equation gives you the velocity, discharge, and flow regime.
Open-Channel Flow (Manning)Live
rivers, canals & storm drains
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Manning’s equation predicts flow in an open channel: V = (1/n)·R^⅔·√S, where R is the hydraulic radius and n the roughness. The Froude number tells you whether flow is tranquil (Fr < 1) or rapid. Educational tool.
Reading this result: Froude number 0.55 is below 1: the flow is subcritical (deep, slow, tranquil), so disturbances can travel upstream and downstream depth controls the flow.
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How it works
Manning's equation, V = (1/n)·R^⅔·√S, predicts open-channel velocity from the hydraulic radius R (area ÷ wetted perimeter), bed slope S, and roughness n. The Froude number classifies the flow as subcritical (tranquil) or supercritical (rapid). Educational tool.
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The solver uses established numerical methods, but results are for research and educational purposes and should be validated against experiment or professional review before you rely on them.