Field-driven dynamics of dilute gases, viscous liquids and polymer chains

This thesis is concerned with the exploration of field-induced dynamical phenomena arising in dilute gases, viscous liquids and polymer chains. The problems considered herein pertain to the slip-induced motion of a rigid, spherical or nonspherical particle in a fluid in the presence of an inhomogeneous temperature or concentration field or an electric field, and the dynamics of charged polymers animated by the application of an electric field. The problems studied in this thesis are unified by the existence of a separation of length scales between the macroscopic phenomena of interest and their microscopic underpinnings, and are treated by means of coarse-graining principles that exploit this scale separation. Specifically, the first part of this thesis investigates the dynamics caused by the existence of a slip velocity at a fluid-solid interface. The macroscopic slip boundary condition obtains from the asymptotic matching of the velocity within the microscale layer of fluid adjoining the solid surface, and the velocity in the bulk fluid. In the case of a gas, the microscopic length scale is constituted by the mean free path, and the layer of gas adjoining the solid boundary having a thickness of the order of the mean free path is referred to as the Knudsen layer. The parameter representing the ratio of the mean free path to the macroscopic length scale is the Knudsen number, denoted Kn. The widely-used Navier-Stokes and Fourier equations are valid away from the solid boundary at distances large compared to the mean free path in the limit Kn < 1, and necessitate the imposition of continuum boundary conditions on the gas velocity and temperature at the outer limit of the Knudsen layer. These macroscopic equations are typically solved subject to the no-slip of velocity and the equality of the gas and solid temperatures at the solid boundary.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Chemical Engineering

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Mohan, Aruna, 1981-

Advisor dc:contributor.advisor

• Patrick S. Doyle and Howard Brenner.

• Chemical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/42429
• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Identifier URI

http://dspace.mit.edu/handle/1721.1/42429

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/42429