Bernoulli Tube
INTERACTIVE PHYSICS DEMO
Air speeds up through the narrow throat — and pressure drops. Drag the slider to squeeze the tube.
Bernoulli's Principle
P + ½ρv² = const  ·  ↑v at throat → ↓P  ·  ↑P wide sections
Throat ratio: 40%
Inlet
Low velocity
High pressure
Wide cross-section → air moves slowly
Throat
High velocity
Low pressure
Narrow section → air must speed up
Outlet
Low velocity
High pressure
Widens again → slows down, pressure recovers
INLET
Wide Section A
P
V
—
PRESSURE
—
m/s
THROAT
Narrow Throat B
P
V
—
PRESSURE
—
m/s
OUTLET
Wide Section C
P
V
—
PRESSURE
—
m/s
Flow Speed 6 m/s
Throat Size 40%
A1v1 = A2v2  (continuity)
P1 + ½ρv1² = P2 + ½ρv2²