Abstract:
The computation of phase and chemical equilibria of aqueous organic electrolytes mixtures is of significant interest in atmospheric aerosol modeling. We present here computational methods for the prediction of the physical equilibrium state of atmospheric particles by investigating two optimization problems derived from the minimization of the total Gibbs energy.
In the case of inorganical aerosols, the computational difficulty is to identify the solid phases existing at the equilibrium. The method we propose is based on an active sets/Newton method for the solution of the Karush-Kuhn-Tucker (KKT) conditions. It takes advantage of the fact that the inequality constraints determining the presence of the solid salts are linear.
In the case of organical aerosols, liquid-liquid and liquid-solid equilibria as well as phase separation are considered. We propose a primal-dual interior-point method to solve the KKT conditions of a relaxed minimization problem.
We present numerical results for both inorganic and organic problems to show the ability of our approach, in the prediction of aerosol phases in the atmospheric particles.
Future talks in Scientific Computing Seminar
Oct. 5: M. F. Wheeler, TICAM, the University of Texas at Austin.
Oct. 7: J. Rappaz: Institute of Analysis and Scientific Computing, EPFL, Switzerland
Oct. 28: L. Fauci, Dept. of Mathematics, Tulane University.
Nov. 4: C. Carstensen, Institute of Mathematics, Humboldt University, Berlin
Nov. 18: Jiwen He, Department of Mathematics, University of Houston
Nov. 23: O. Pironneau, Universite Pierre-et-Marie-Curie, France
This seminar is easily accessible to persons with disabilities. For more information or for assistance, please contact the Mathematics Department at 743-3500.