Interactive Teaching Tool · Continuity · Bernoulli · Reynolds

🌊 Bernoulli Flow Lab

Push fluid through a venturi and watch it speed up in the throat (continuity), lose pressure (Bernoulli), and switch between laminar and turbulent flow (Reynolds). Squeeze the throat too hard and you'll see cavitation. Then take on the Flow Challenges. Built for fluid-mechanics & hydraulics students.

Flow rate, Q 40 L/s

Inlet diameter, D₁ 150 mm

Throat diameter, D₂ 60 mm

Automatically kept ≤ inlet diameter.

Inlet pressure, p₁ 200 kPa

Gauge pressure at the wide inlet.

Working fluid

Inlet velocity V₁

m/s

Throat velocity V₂

m/s

Throat pressure p₂

kPa gauge

Reynolds (throat)

— — Contraction ratio —

The physics behind the game

Continuity forces the fluid faster through the narrow throat; Bernoulli's equation then trades that kinetic energy for a pressure drop:

A = πD²/4 • V = Q/A • p₂ = p₁ + ½ρ(V₁² − V₂²) • Re = ρV₂D₂/μ

Flow is laminar for Re < 2300, transitional up to ~4000, and turbulent above. If the throat's absolute pressure falls below the fluid's vapour pressure, the liquid boils locally — cavitation — the effect that erodes pumps, valves and propellers. The model assumes steady, incompressible, ideal flow (losses neglected), so treat the numbers as teaching illustrations rather than a calibrated design.