Interactive engineering model
Manning open-channel prism
Compare rectangular, trapezoidal, and triangular cross-sections while flow area and wetted perimeter drive Manning discharge.
Preparing the 3D model...
An earth channel with a translucent near bank exposes the water prism, with the wetted perimeter traced in rose across the downstream face and an amber free-surface line at the top width. Far-bank roughness elements coarsen as Manning's n rises, with their size limited to preserve narrow sections. A velocity arrow scales with the solved velocity, and the reach tilts by a stated exaggeration of the bed slope. Readouts report area, perimeter, hydraulic radius, velocity, and discharge; near-critical denotes the teaching tolerance from Froude 0.95 to 1.05.
Diagram labels
Numbers match the callouts in the view. Drag to inspect the model; crowded callouts remain listed here.
Focus the 3D view and use the arrow keys to orbit, plus or minus to zoom, and Home to reset the view.
Text explanation and non-WebGL fallback
An earth channel with a translucent near bank exposes the water prism, with the wetted perimeter traced in rose across the downstream face and an amber free-surface line at the top width. Far-bank roughness elements coarsen as Manning's n rises, with their size limited to preserve narrow sections. A velocity arrow scales with the solved velocity, and the reach tilts by a stated exaggeration of the bed slope. Readouts report area, perimeter, hydraulic radius, velocity, and discharge; near-critical denotes the teaching tolerance from Froude 0.95 to 1.05.
The numeric controls and readouts remain usable if WebGL is unavailable. Drag or swipe the 3D view to orbit and use a wheel or pinch gesture to zoom. With the 3D view focused, use the arrow keys to orbit, plus or minus to zoom, and Home to reset. The complete numeric lesson is also keyboard-accessible in the adjacent controls and readouts. This model is an educational aid and does not replace applicable design standards or professional review.