Venturi / Bernoulli

Venturi tube — incompressible continuity gives A₁v₁=A₂v₂. Bernoulli then predicts a pressure drop at the constriction: Δp=½ρ(v₂²−v₁²). Educational inviscid model at equal height (water ρ≈998 kg/m³). Equal diameters are allowed as a zero-pressure-drop check. A non-positive throat pressure marks the limit of this ideal model; cavitation and losses are omitted.