Flow coefficients are determined experimentally and are a function of the
shape of the passage, the Reynolds number and Mach number of the flow, and
the gas properties. For a Mach number at the throat less than about 0.7 and for
passages of similar shape, the flow coefficient is essentially a function of Reynolds
number only.
Orifice plates are frequently used to measure gas flow rates. Standard
methods for determining flows through orifice plates can be found in Ref. 3.
REFERENCES
1. Lichtarowicz, A., Duggins, R. K., and Markland, E.: "Discharge Codficients for Incompressible
Non-Cavitating Flow through Long Orifices," J. Mech. Eng. Sci., vol. 7, no. 2, pp. 210-219,1965.
2. Taylor, C. F.: The Internal Combustion Engine in Theory and Practice, vol. I, p. 506, MIT Press,
1966.
3. Marks' Standmd Handbookjiw Mechanical Engineers, 8th ed., McGraw-Hi, 1978.
APPENDIX
DATA
ON
WORKING
FLUIDS
TABLE D.l
TABLE D.2
Thermodynamic properties of air at low density?
Standard entbalpy of formation and molecular weight of species
Sped-
Fornula
oxygen
Nitrogen
Carbon
Carbon
monoxide
Carbon
dioxide
Hydrogen
Water
Water
Methane
Propane
Ismtane
Isooctane
Cetane
Methyl
alwhol
Methyl
alcohol
Ethyl
alcohol
Ethyl
alcohol
0,
N,
C
CO
Mokeolu
mi*
g/de
32.00
28.01
12.011
28.01
(Graphs, Tables, and Computational Equations for Forty Substances), by W. C. Reynolds, Published by the Department of Mechanical Engineering, Stanford
University, Stanford,CA 94305,1979.
gas
gas
solid
gas
CO,
Hz
Hz0
H2O
CH4
C,H,
C,H,,
C,H,,
CH,OH
2.016
18.02
18.02
16.04
44.10
114.23
114.23
226.44
32.04
liquid
liquid
gas
CH,OH
32.04
liquid
46.07
liquid
'16~34
gas
gas
liquid
gas
gas
gaS
C,H,OH
C2H,0H
t At 298.15 K (25•‹C)and I atrn. '
t Abstracted with permission from Thermodynamic Properties in SI
Statet
MJ/kmol
@I
kd/mol
TABLE D3
Enthalpy of C, CO, CO, ,Hz, H,O, N, ,0,
h'q I) -&298.ls), kcd/mol
T(K)
c
CO
CO,
Ha
Ha0
N,
0,
Source: JANAF Tkmochemiul Tables, National Bureau of Standards Publication NSRDS
NBS37.1971.
qs3
*
"
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-
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c
CO
CO,
Ha
Ha0
h'q I) -&298.ls), kcd/mol
Enthalpy of C, CO, CO, ,Hz, H,O, N, ,0,
TABLE D3
T(K)
N,
0,
Source: JANAF Tkmochemiul Tables, National Bureau of Standards Publication NSRDS
NBS37.1971.
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*
"
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-
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xSsTdS $3 "32
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58 x