Summary: INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
Int. J. Numer. Meth. Engng 2003; 56:1023≠1050 (DOI: 10.1002/nme.598)
Transient analysis of electro-osmotic transport by a
reduced-order modelling approach
and N. R. Aluru2;;
1Department of Mechanical and Industrial Engineering; University of Illinois at Urbana-Champaign;
Urbana; IL 61801; U.S.A.
2Department of General Engineering and Beckman Institute for Advanced Science and Technology;
University of Illinois at Urbana-Champaign; Urbana; IL 61801; U.S.A.
Transient behaviour of electro-osmotic transport in typical electrokinetic channels is studied in this
paper. The time needed for the electro-osmotic ow to reach steady-state exhibits multiple time scales
depending on whether the ow is governed by either a viscous force, electrokinetic force or by a
combination of both. When an intersection is present in the electrokinetic channel, such as in a cross or
a T-channel, the ow in the main channel and in the intersection gets to steady-state at di erent times.
A weighted Karhunen≠Lo¬eve (KL) decomposition method is proposed in this paper to generate the
global basis function for reduced-order simulation. The key idea in a weighted KL approach is that,
instead of minimizing a least-squares measure of `error' between the linear subspace spanned by the
basis functions and the observation space, we minimize the weighted `error' between the two spaces.