Open Channel (Manning) Calculator
Calculate normal and critical depth with Manning in rectangular, trapezoidal, and triangular sections, with curves, table, and CSV export.
Open channels (Manning): normal and critical depth
Solve uniform flow, critical depth, Froude, and specific energy. Includes curves, table, comparison, and CSV export.
Input data
Basic
Increase y_max if the bracket is not found.
Advanced
Results
Normal depth y_n
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Critical depth y_c
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Velocity V(y_n)
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Froude Fr(y_n)
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Area A(y_n)
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Hydraulic radius R(y_n)
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Top width T(y_n)
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Specific energy E(y_n)
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Assumptions: uniform flow, slope S ≈ energy slope, constant n.
Section and depths
Curves and sweep table
Q(y) uses Manning; V, Fr, and E(y) use the target discharge.
Manning Q(y)
Specific energy E(y)
Froude Fr(y)
| y | A | P | R | T | Q(y) | V(y) | Fr(y) | E(y) |
|---|
Compare scenarios
Compare depths, Froude, and capacity Q(y_max) for two scenarios.
Scenario A
Scenario B
Comparative Q(y)
Step by step
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