Orifice Area

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orifice liquid 1

Tags:  Area Orifice and Nozzle

Orifice area refers to the area cross-section of an orifice, which is a small opening or hole through which fluid flows.  The orifice area is an important parameter in fluid dynamics and flow calculations, particularly in applications such as pipes, nozzles, and valves.

  • Geometric Orifice Area (GOA)  -  The orifice opening
  • Effective Orifice Area (EOA)  -  The minimal cross-section area of the downstream jet.
  • Contraction Coefficient (\(C_c\))  -  The ratio of the area measured at the vena contracta (EOA), to the area of the orifice (GOA) or \(C_c = \frac{EOA}{GOA}\)
  • Discharge Coefficient (\(C_d\))  -  The ratio of actual flow to ideal flow or \(C_d = \frac{Q_a}{Q_i}\)

 

Orifice Area formula

\(\large{ A_0 =  \frac{ Q  }{ C_d \; \sqrt{ 2 \; G \; h }  }   }\)     (Orifice Area)

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

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

\(\large{ G =  \frac{  \left(  \frac{ Q }{ C_d \; A_o } \right)^2  }{ 2  \; h  }   }\) 

\(\large{ h =  \frac{  \left(  \frac{ Q }{ A_o \; C_d } \right)^2  }{  2  \; G  }   }\) 

Solve for Ao

orifice flow rate, Q
orifice discharge coefficient, Cd
orifice gravitational constant, G
orifice center of head, h

Solve for Q

orifice area, Ao
orifice discharge coefficient, Cd
orifice gravitational constant, G
orifice center of head, h

Solve for Cd

orifice flow rate, Q
orifice area, Ao
orifice gravitational constant, G
orifice center of head,h

Solve for G

orifice flow rate, Q
orifice area, Ao
orifice discharge coefficient, Cd
orifice center of head, h

Solve for h

orifice flow rate, Q
orifice area, Ao
orifice discharge coefficient, Cd
orifice gravitational constant, G

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

 

Piping Designer Logo Slide 1

Tags: Area Orifice and Nozzle