Page 238 - Modelling in Transport Phenomena A Conceptual Approach

218 CHAPTER 7. UNSTEADY-STATE MACROSCOPIC BALANCES

L length, m
m mass flow rate, kg/s
M molecular weight, kg/ kmol
n molar flow rate, kmol/s
P pressure, Pa
Q heat transfer rate, W
Q volumetric flow rate, m3/ s
r rate of a chemical reaction, kmol/ m3. s
R gas constant, J/mol. K
T temperature, "Cor K
t time, s
U internal energy, J
V volume, m3
V velocity, m/ s
w rate of work, W
ws rate of shaft work, W
X fractional conversion
Xi mole fraction of species i
CY thermal diffusivity, m2/ s
stoichiometric coefficient of ith species in the jth reaction
"ij
Y CP/G
A difference
AH,,, heat of reaction, J
E molar extent of a reaction, kmol
x latent heat, J
s
U kinematic viscosity (or, momentum diffusivity), m2/
P density, kg/ m3
7 residence time, s
Overlines

per mole
N
per unit mass
- partial molar

Bracket

(4 average value of a

Superscripts

0 standard state
S solid
sat saturation