LHV
Lower heating value, kJ/kg fuel
m
Mass, kg
_
m
Mass flow rate, kg/s
M
Molar mass, kg/kmol
MEH
Mechanical equivalent of heat
MTH
Mechanical theory of heat
n
Normal unit vector
N
Number of moles, kmol
p
Pressure, kPa
p i
Partial pressure, kPa
p 0
Surroundings pressure, kPa
p 0
Pressure at 1 atm (101.325 kPa)
p
r
Under constant reservoir pressure
PE
Potential energy, kJ
PETH Predicative entropic theory of heat
q
Heat transfer per unit mass, kJ/kg
q
Heat transfer per unit molar mass, kJ/kmol
Q
Heat transfer, kJ
_
Q
Heat transfer rate, kW
Q H
Heat transfer with high-temperature body
Q A
Heat transfer with high-temperature body
Q L
Heat transfer with low-temperature body
Q C
Heat transfer with low-temperature, i.e., cold body
Q B
Heat transfer with low-temperature body
Q rev
System heat exchange of reversible event
Q spon
System heat exchange of spontaneous event
D ^
Q
Additional heat extracted for the reversible event, ¼ Q rev À Q spon
R
Universal gas constant, 8.31447 kJ/kmol-K
R i
Gas constant of ith specie, kJ/kg-K
s
Specific entropy, kJ/kg-K
s
Molar specific entropy, kJ/kmol-K
S
Entropy, kJ/K
t
Time, s
T
Temperature,
o C or K
T H
Temperature of high-temperature body, K
T A
Temperature of high-temperature body, K
T L
Temperature of low-temperature body, K
T C
Temperature of low-temperature cold body, K
T B
Temperature of low-temperature body, K
T 0
Surroundings temperature, K
T 0
Standard temperature at 298.15 K
T
r
Under constant reservoir temperature
u
Specific internal energy, kJ/kg
u
Molar specific internal energy, kJ/kmol
xviii
Symbols and Abbreviations