Engineering & mechanics
Venturi liquid flow estimate
Calculate volume flow from upstream/throat diameters and differential pressure.
A clear answer. Here’s how.
Uses Q=Cd·A₂·sqrt(2ΔP/[ρ(1−β⁴)]), β=D₂/D₁, for steady incompressible flow at equal elevation. Throat diameter must be smaller than upstream diameter. The supplied coefficient accounts approximately for non-ideal flow. No gas expansion correction, installation standard, pressure-tap specification or uncertainty is inferred.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- Upstream internal diameter (mm)
- 50
- Throat diameter (mm)
- 25
- Upstream minus throat pressure (kPa)
- 10
- Fluid density (kg/m³)
- 1000
- Supplied discharge coefficient
- 0.98
Example result
- Volume flow (L/min)
- 133.314253271
- Throat velocity (m/s)
- 4.52642611045
- Upstream velocity (m/s)
- 1.13160652761
- Diameter ratio beta
- 0.5