Page 303 - Formulas and Calculations for Petroleum Engineering

296 Formulas and calculations for petroleum engineering

5.88 Influence of changing interfacial area on mass transfer

Input(s)
c AO : Concentration (g mol/cm)
2
D AB : Diffusivity (cm /s)
t: Time (s)
a: Constant (dimensionless)

Output(s)
M A : Molar Rate (mol/s)

Formula(s)

0:5

2 0:667 + 1
4 D AB t
M ¼ c
A AO
p 2 0:667 + 1Þ
ð
Reference: Bird, R.B., Stewart, W.E. and Lightfoot, E.N. (2002). Transport Phenomena (Second Ed.). John Wiley & Sons.
Chapter: 20, Page: 623.

5.89 Knudsen flow
Input(s)

m: Molecular Mass (g)
2
1
K: Boltzmann Constant (m kg s 2 K )
T: Temperature (Kelvin)
R: Radius (m)
po: Pressure at Initial point (Pa)
pL: Pressure at point L (Pa)
L: Length (m)

Output(s)
w: Mass Rate Flow (kg/s)

Formula(s)

m 4 3 po pL

w ¼ sqrt 2 R ’
K T 3 L

Reference: Wikipedia.org.

5.90 Krieger Dougherty equation viscosity ratio

Input(s)

ø: Porosity (fraction)
A: Dimensionless Constant (dimensionless)
ø max : Volume Fraction for the Spheres (fraction)