Nozzle Coefficient Lookup Table

Detailed Description

These coefficients parameterize the quadratic flow-versus-pressure relationship for each nozzle type. Given a supply pressure \(P\) \([\unit{\psi}]\), the single-nozzle flow rate is computed as:

\begin{equation}\label{eq:compressed-air-nozzle-flow-rate} Q_{nozzle} = a \cdot P^2 + b \cdot P + c\end{equation}

where \(a\), \(b\), and \(c\) are the nozzle-type-specific empirical coefficients listed in the table below. Each index (0–12) represents a distinct nozzle geometry; the coefficients were fitted to measured flow data at known pressures.

Coefficient Table

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The following table lists the empirical quadratic coefficients \(a\), \(b\), and \(c\) for each of the 12 supported nozzle types. Select the row whose index matches the nozzle_type field of compressed_air_reduction::PressureMethodData.

Index	Nozzle Type	\(a\) \([\unit{\scfm\per\psi\squared}]\)	\(b\) \([\unit{\scfm\per\psi}]\)	\(c\) \([\unit{\scfm}]\)
0	1.0 mm nozzle	\(-2.200 \times 10^{-7}\)	0.018893	0.268476
1	1.5 mm nozzle	\(-2.800 \times 10^{-5}\)	0.038377	1.061905
2	1/4" pipe, open	\f$-7.600 \times 10^{-5}\f$	1.537424	14.300000
3	1/4" tubing	\f$-2.200 \times 10^{-5}\f$	0.345931	5.780952
4	1/8" pipe, open	\f$6.820 \times 10^{-4}\f$	0.643182	13.833330
5	1/8" tubing	\f$5.410 \times 10^{-6}\f$	0.228851	2.968095
6	2.0 mm nozzle	\(-2.100 \times 10^{-6}\)	0.075463	1.089857
7	2.5 mm nozzle	\(-2.800 \times 10^{-5}\)	0.148710	1.841905
8	3/8" pipe, open	\f$2.652 \times 10^{-3}\f$	2.250152	46.566670
9	3/8" tubing	\f$7.470 \times 10^{-4}\f$	0.842056	15.957140
10	5/16" tubing	\f$4.110 \times 10^{-4}\f$	0.560649	10.161900
11	Air Knife	\(9.350 \times 10^{-4}\)	0.130792	4.429524

See also

Orifice/Pressure Method Flow Rate Formula for the formula that uses these coefficients.

Modules
	Nozzle Coefficient Data