Flow Measurement

Accurate measurement of fluid flow is essential in engineering.

Orifices

An opening in a tank through which fluid flows. Theoretical Velocity: $V_{th} = \sqrt{2gh}$ (Torricelli's Theorem) Actual Discharge: $Q = C_d A \sqrt{2gh}$

• $C_d$ = Coefficient of discharge ($C_d = C_c C_v$)

Venturi Meters

A converging-diverging pipe section used to measure flow. High accuracy, low head loss. $Q = C_d A_1 A_2 \sqrt{\frac{2g(h_1-h_2)}{A_1^2 - A_2^2}}$

Weirs

Barriers across open channels. Rectangular Weir (Francis Formula): $Q = 1.84 L H^{3/2}$ Triangular (V-Notch) Weir: $Q = C H^{5/2}$

Solved Problems