Symbol
A
aw
B
b
C
c
D
D
D
d
E
F
f
f
G
G
g
H
H
H
h
~
h
∆h v
I
J
K
K
L
M
~
M
&
M
&
m
N
N
&
N
n
n
n
n&
P
P
p
&
Q
q&
R
R
~
R
r
Alternative
Quantity or parameter
Symbol
surface area
water activity
nucleation rate
breakage function
constant or coefficient
specific heat capacity
equipment diameter
diffusion coefficient
Γ, δ
transport tensor
diameter or size of solids
energy
mass flux function
relative (normalized) drying rate
multi-dimensional number density
shear function or modulus
growth rate
acceleration due to gravity
height
enthalpy
Heaviside step function
specific enthalpy (dry basis)
hN
molar enthalpy
specific enthalpy of evaporation
total number of intervals
numerical flux function
constant
dilatation function or bulk modulus
length
m
mass
M, MN
molecular mass
W
mass flow rate
J
mass flux, drying rate
number
molar amount
WN
molar flow rate
molar density, molar concentration
number density
outward normal unit vector
molar flux
JN
power
total pressure
partial pressure / vapour pressure of component
Q
heat flow rate
q
heat flux
equipment radius
individual gas constant
RN
universal gas constant
radial coordinate
Units
m2
kg-1m-1s-1
m-3
J/kgK
m
m²/s
m²/s
m
J
Pa
kg/s
m/s2
m
J
J/kg
J/mol
J/kg
m
kg
kg/kmol
kg/s
kg/m²s
mol
mol/s
mol/m³
m-3
mol/m²s
W
kg m/s2
kg m/s2
W
W/m2
m
J/kgK
J/kmolK
m
r
S
S
s
T
t
u
u
V
&
V
v
v
v
W
w
X
x
x
x
x
x0
~
x
Y
y
y
~y
z
pore (throat) radius
saturation
selection function
boundary layer thickness
temperature
time
velocity in z-direction
displacement
volume
volumetric flow rate
specific volume
velocity in x-direction
general velocity vector
weight force
velocity in y-direction
solids moisture content (dry basis)
mass fraction in liquid phase
particle volume in population balances
lateral coordinate
general eulerian coordinate
general lagrangian coordinate
molar fraction in liquid phase
gas moisture content (dry basis)
lateral coordinate
mass fraction in gas phase
molar fraction in gas phase
axial coordinate
m
1/s
m
K, °C
s
m/s
m
m3
m³/s
m3/kg
m/s
ms-1
N
m/s
m³
m
m
m
m
m
∇⋅
∆
Special symbols
gradient operator
divergence operator
difference operator
-
α
β
β
δ
ε
ε
ε
η
θ
κ
λ
µ
µ
ν
π
Greek letters
heat transfer coefficient
mass transfer coefficient
aggregation kernel
Dirac-delta distribution
voidage
emissivity
strain
efficiency
angle, angular coordinate
thermal diffusivity
thermal conductivity
dynamic viscosity
moment of the particle size distribution
kinematic viscosity
circular constant
F
xN
yN
∇
h
k
W/m²K
m/s
1/s
rad
m²/s
W/mK
kg/ms
m2/s
-
ρ
Σ
σ
σ
σ
σ
τ
Φ
ϕ
ω
density, mass concentration
summation operator
surface tension
Stefan-Boltzmann constant for radiative heat transfer
standard deviation (of pore size distribution)
stress
dimensionless time
characteristic moisture content
relative humidity
angular velocity
a
as
bed
c
c
cr
D
dry
dp
eff
eq
f
g
H
i
i,1,2,…
i,j,k
in
l
m
max
mf
min
N
o
out
P
p
pbe
ph
r
rel
s
S
surf
V
v
w
w
Subscripts
at ambient conditions
at adiabatic saturation conditions
bed
cross section
capillary
at critical moisture content
drag
dry
at dewpoint
effective
equilibrium (moisture content)
friction
gas (dry)
wet (humid) gas
inner
component index, particle index
coordinate index, i,j,k = 1 to 3
inlet value
liquid (alternative: as a superscript)
mean value
maximum
at minimum fluidisation
minimum
molar quantity
outer
outlet value
at constant pressure
particle
population balance equation
at the interface
radiation
relative velocity
solid (compact solid phase), alternative: as a superscript
at saturation conditions
surface
based on volume
vapour, evaporation
water
wall
kg/m3
N/m
W/m2K4
m
Pa
rad
wb
wet
∞
at wet bulb conditions
wet
at large distance from interface
Superscripts
average, phase average
α
v
*
*
intrinsic phase average
volumetric strain
rheological strain
at saturation conditions
Multiple subscripts should be separated by a colon, e.g.: ρ p ,dry : density of dry particle.
Bold symbols denote vector or tensor quantities