Page 13 - Advanced thermodynamics for engineers

xxii NOTATION

Specific Gibbs energy (specific Gibbs function)
g
Specific Gibbs energy at datum temperature (or absolute zero)
g 0
Acceleration due to gravity
g
Gibbs energy (Gibbs function)
G
Specific enthalpy
h
Specific enthalpy at datum temperature (or absolute zero)
h 0
Height
h
Enthalpy
H
Irreversibility
I
Electrical current
i
Thermodynamic velocity, or flow
J
~ Joule’s mechanical equivalent of heat
J
Electrical flow rate
J I
Heat flow rate
J Q
Entropy flow rate
J S
Isothermal compressibility, isothermal bulk modulus
k
Thermal conductivity
k 23
Boltzmann constant (1.38062 10 J/K)
k
Adiabatic, or isentropic, compressibility
k s
Rate of reaction
k
0
Karlovitz number ½ðu =[ T Þðd [ =u [ ފ
K
Specific thrust coefficient of nozzle
K F
Equilibrium constant
K p
l Length
Taylor microscale
l T
Coefficient relating thermodynamic force and velocity
L
Lewis number½l=pc p DŠ
Le
Mass
m
_ Mass flow rate
m
Molecular weight
m w
MCFC Molten carbonate fuel cell
Polytropic index
n
Amount of substance, chemical amount (sometimes referred to as number of moles)
n
Reaction order
n
Engine speed (rev/min)
N
~ Avogadro constant (6.023 10 26 kmol )
1
N
Pressure
p
Mean effective pressure
p
Partial pressure of component i
p i
Datum pressure (often 1 bar or 1 atm)
p 0
Preparation rate (Whitehouse and Way equation.)
P
Power output
P
PAFC Phosphoric acid fuel cell
PEMFC Proton exchange membrane fuel cell
Prandtl number ½c p m=kŠ
P r