Orifice Discharge Coefficient

Written by Jerry Ratzlaff on . Posted in Flow Instrument

orifice liquid 1Orifice discharge coefficient, abbreviated as \(C_d\), a dimensionless number, is the ratio of actual discharge to the theoretical discharge.

 

Orifice Discharge Coefficient formula

\(\large{ C_d =   \frac { Q }  { A_o \; \sqrt { 2 \; G \; h }     }   }\)  

Where:

 Units English Metric
\(\large{ C_d  }\) = orifice discharge coefficient \(\large{ dimensionless }\)
\(\large{ A_o }\) = orifice area \(\large{ in^2 }\) \(\large{ mm^2 }\)
\(\large{ h }\) = orifice center of head \(\large{ in }\) \(\large{ mm }\)
\(\large{ Q }\) = orifice flow rate \(\large{\frac{ft^3}{sec}}\) \(\large{\frac{m^3}{s}}\)
\(\large{ G }\) = orifice gravitational constant \(\large{\frac{lbf-ft^2}{lbm^2}}\)  \(\large{\frac{N - m^2}{kg^2}}\) 

 

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Tags: Coefficient Equations Orifice and Nozzle Equations