Venturi Meter Calculator — Formula
## Venturi Meter Flow Measurement
A Venturi meter uses a converging-diverging section to measure flow with minimal permanent pressure loss.
### Formula
**Q = Cd A2 sqrt(2 delta_P / (rho (1 - beta^4)))**
where A2 is the throat area, beta = D2/D1 is the diameter ratio, and the (1 - beta^4) term accounts for the velocity change between upstream and throat. Cd for Venturi meters is typically 0.95-0.99.
A Venturi meter uses a converging-diverging section to measure flow with minimal permanent pressure loss.
### Formula
**Q = Cd A2 sqrt(2 delta_P / (rho (1 - beta^4)))**
where A2 is the throat area, beta = D2/D1 is the diameter ratio, and the (1 - beta^4) term accounts for the velocity change between upstream and throat. Cd for Venturi meters is typically 0.95-0.99.
Exemplo Resolvido
A Venturi with 100 mm upstream and 50 mm throat, 15 kPa differential, water.
- beta = 50/100 = 0.5, beta^4 = 0.0625
- A2 = pi x 0.05^2 / 4 = 0.001963 m^2
- sqrt(2 x 15000 / (1000 x (1 - 0.0625))) = sqrt(30000/937.5) = sqrt(32) = 5.657 m/s
- Q = 0.98 x 0.001963 x 5.657 = 0.01088 m^3/s = 10.88 L/s