|
Gases, kinetic theory
|
|
symbol
|
standard
units
|
description
|
alternative
units
|
|
P
|
Pa
|
Pressure
|
Torr, atm
|
|
V
|
m3
|
volume
|
cm3, liter
|
|
N
|
moles
|
number of moles
|
|
|
R
|
J/mole K
|
universal gas constant
|
liter atm/mole °C, torr liter/mole
°C
|
|
T
|
K
|
temperature
|
°C
|
|
m
|
kg
|
molecular mass
|
gm, amu
|
|
k
|
joules/K
|
Boltzmann's constant
|
ev/K, erg/K
|
|
v
|
m/s
|
molecular velocity
|
cm/s
|
|
c
|
m/s
|
average molecular velocity (various)
|
cm/s
|
|
J
|
#/m2 sec
|
flux (number crossing unit area/time)
|
#/cm2 sec
|
|
n
|
#/m3
|
molecular density
|
#/cm3
|
|
M
|
g/mole
|
molar mass
|
kgm/mole
|
|
Lambda
|
m
|
mean free path
|
cm
|
|
a
|
m
|
effective molecular diameter
|
cm
|
|
|
Reactor analysis
|
|
X
|
[dimensionless]
|
utilization
|
|
|
Rs
|
moles/second
|
surface reaction rate
|
molecules/second
|
|
Ks
|
m/sec
|
surface reaction rate constant (first order)
|
cm/second
|
|
S
|
m2
|
surface area
|
cm2
|
|
[species]
|
moles/m3
|
concentration of species
|
moles/cm3, molecules/cm3
|
|
Q
|
moles
|
total reactant
|
molecules
|
|
Fin
|
m3/sec
|
volumetric flow in (or out)
|
cm3/sec
|
|
tres
|
seconds
|
residence time
|
|
|
tcon
|
seconds
|
consumption time
|
|
|
NAv
|
#/gm mole
|
Avogadro's number
|
|
|
|
Mass Transport
|
|
D
|
m2/sec
|
diffusion constant
|
cm2/sec
|
|
A
|
m2
|
cross-sectional area
|
cm2
|
|
Ld
|
m
|
diffusion length
|
cm
|
|
L
|
m
|
characteristic system length
|
cm
|
|
Pe
|
[dimensionless]
|
Peclet number = (feature size/diffusion
length)^2
|
|
|
Rhom
|
moles/m3
|
molar density
|
moles/cm3
|
|
Rho
|
kg/m3
|
mass density
|
g/cm3
|
|
U
|
m/sec
|
fluid velocity
|
cm/sec
|
|
Mu
|
kg/m sec
|
viscosity
|
gm/cm sec = Poise
|
|
Re
|
[dimensionless]
|
Reynolds number = (feature size/momentum
diffusion length)^2
|
|
|
Fsccm
|
std. cm3/min
|
molar flow (standard units)
|
|
|
H
|
m
|
height of chamber
|
cm
|
|
r
|
m
|
radial distance
|
cm
|
|
Rc
|
m
|
radius of chamber
|
cm
|
|
Fm
|
moles/second
|
molar flow
|
|
|
C
|
molecules/m3
|
molar concentration
|
moles/cm3
|
|
LTh
|
m
|
Thiele length
|
cm
|
|
Nu
|
m2/sec
|
kinematic viscosity, mu/rho
|
cm2/sec
|
|
|
Heat Transport
|
|
cp
|
J/kgm
|
heat capacity at constant pressure
|
J/gm
|
|
cvol
|
J/m3
|
volumetric heat capacity
|
J/cm3
|
|
Kth
|
W/m K
|
thermal conductivity
|
W/cm K
|
|
c
|
m/s
|
velocity of light
|
cm/s
|
|
Sigma
|
W/m2 K4
|
Stefan-Boltzmann constant
|
W/cm2 K4
|
|
Epsilon
|
[dimensionless]
|
emissivity
|
|
|
Pm
|
W/m2
|
radiated power
|
W/cm2
|
|
d
|
m
|
gap between planes
|
cm
|
|
|
Chemistry
|
|
G
|
Joules/mole
|
free enthalpy or Gibbs Free Energy
|
calories/mole
|
|
S
|
Joules/mole K
|
entropy
|
calories/mole
|
|
E
|
Joules/mole
|
internal energy
|
calories/mole
|
|
H
|
Joules/mole
|
enthalpy
|
calories/mole
|
|
Hvap
|
Joules/mole
|
heat of vaporization
|
calories/mole
|
|
E sub a
|
Joules/mole
|
activation energy
|
calories/mole
|
|
Theta
|
[dimensionless]
|
fraction of occupied surface sites
|
|
|
RSC
|
[dimensionless]
|
reactive sticking coefficient
|
|
|
