Degree Type
Thesis
Date of Award
January 2009
Degree Name
Master of Science
Department
Aerospace Engineering
First Advisor
Paul A. Durbin
Abstract
A computational study is performed to study mixing characteristics in electrohydrodynamic flows at length scales of a micro-metre. A t-shaped microchannel is analyzed where two fluids of differing electrical conductivities are allowed to mix under the application of an external electric field. A two dimensional finite volume code based on the SIMPLE algorithm is employed. The effect of mixing is characterized in terms of a nondimensional parameter λ measuring the relative magnitude of the Coulombic force due to the electric field to the inertia force. Based on the relative concentrations of the two mixing streams a mixing efficiency is proposed and the mixing characteristics are studied by varying the value of the parameter λ (while keeping the concentration ratio fixed). Some observations regarding the time period of oscillation of the disturbance in the absence of any forcing are reported. Simulations are also performed by oscillating the applied external electric field to see the effect it has on the mixing compared to the case with the d.c. electric field. It was observed that oscillation of the electric field at the natural frequency significantly enhances the mixing quite in agreement with the general character of experimental observations. Simulation results for these different cases are presented.
Copyright Owner
Shibi Vasisht Kapisthalam Vasudevan
Copyright Date
2009
Language
en
Date Available
2012-04-29
File Format
application/pdf
Recommended Citation
Kapisthalam Vasudevan, Shibi Vasisht, "Electrohydrodynamic instabilities in microchannels: a computational study" (2009). Graduate Theses and Dissertations. Paper 10619.
http://lib.dr.iastate.edu/etd/10619