An upstream pool spills over a broad-crested structure into a stepped chute and basin. Compare the ideal free-overflow discharge with a selected submerged-flow teaching correction.
• 3D scene parts: Upstream pool; broad spillway crest; stepped discharge chute; tailwater basin; overflow sheet. • Controls: Upstream head above crest (0.1–3 m); Crest width (2–12 m); SI discharge coefficient (1.3–1.9 m½/s); Tailwater above crest (0–3 m). • Live readouts: Free overflow (m³/s); Corrected discharge (m³/s); Tailwater/head ratio; Submergence factor; Critical-section velocity (m/s); Ideal critical depth (m). • Guided experiments: Double head; Drowned crest; Wide crest. • Four tabs (visual laboratory, curves and measurements, experiments, learn and assess), a model-verification run, a timestamped event log and a trial report.
Qfree=C b H^(3/2) Ideal broad-crest yc=2H/3 Teaching drowning factor F=√[1−min(tail/H,1)²] Q=Qfree F; tail≥H gives zero forward overflow
Idealized broad-crested overflow with independently selected SI coefficient. The drowning factor is explicitly a teaching approximation, not a validated structure rating. No approach loss, aeration, scour, reverse flow or dam-safety evaluation. Try the preset experiments, then compare the live readouts with the equations.
No. The free-overflow relation uses H to the power 1.5.
No. It is a declared teaching approximation.
Idealized broad-crested overflow with independently selected SI coefficient. The drowning factor is explicitly a teaching approximation, not a validated structure rating. No approach loss, aeration, scour, reverse flow or dam-safety evaluation.