Event Type:

Applied Mathematics and Computation Seminar

Date/Time:

Friday, November 6, 2009 - 04:00

Location:

GLK 113

Event Link:

Guest Speaker:

Institution:

University of Texas at El-Paso

Abstract:

Recent experimental studies of downward migration of polydisperse,

micron-sized particles in porous media revealed that the classical

colloid filtration theory fails to adequately predict irreversibly

attached particle concentrations. This failure stems from an observed

non-linear decrease

in the irreversible particle attachment with transport distance. Here we

present

a theoretical analysis based on particle size distribution that captures

the

key features of these experimental results. We find that irreversible

attachment

rates are influenced by the surface area of particles rather than mass

or volume, as expressed by a strong correlation between the irreversible

attachment

rate and the radius of the particles squared. Our analysis reveals

that a small fraction (less than four percent) of the poly-disperse

particle population

is responsible for a decrease in the average irreversible attachment

with transport distance. These particles have a larger average diameter

than

the rest of the population and, consequently, a higher than average

irreversible

attachment rate. Hence, the dependence of irreversible particle

attachment

on transport distance is a consequence of the non-uniformity of the

particle

sizes.