https://hal.science/hal-00327976Amundson, N. R.N. R.AmundsonDepartment of Mathematics - UBC - University of British ColumbiaCaboussat, A.A.CaboussatDepartment of Mathematics - UBC - University of British ColumbiaHe, J. W.J. W.HeDepartment of Mathematics - UBC - University of British ColumbiaMartynenko, A. V.A. V.MartynenkoDepartment of Mathematics - UBC - University of British ColumbiaSavarin, V. B.V. B.SavarinENSTA Paris - École Nationale Supérieure de Techniques AvancéesSeinfeld, J. H.J. H.SeinfeldDepartments of Chemical Engineering and Environmental Science and Engineering - Departments of Chemical Engineering and Environmental Science and EngineeringYoo, K. Y.K. Y.YooDepartment of Chemical Engineering - Department of chemical engineeringA computationally efficient inorganic atmospheric aerosol phase equilibrium model (UHAERO)HAL CCSD2005[SDU.OCEAN] Sciences of the Universe [physics]/Ocean, AtmosphereEGU, Publication2005-09-28 08:00:002022-05-11 12:06:062008-06-18 08:00:00enJournal articlesapplication/pdf1A variety of thermodynamic models have been developed to predict inorganic gas-aerosol equilibrium. To achieve computational efficiency a number of the models rely on a priori specification of the phases present in certain relative humidity regimes. Presented here is a new computational model, named UHAERO, that is both efficient and rigorously computes phase behavior without any a priori specification. The computational implementation is based on minimization of the Gibbs free energy using a primal-dual method, coupled to a Newton iteration. The mathematical details of the solution are given elsewhere. The model also computes deliquescence and crystallization behavior without any a priori specification of the relative humidities of deliquescence or crystallization. Detailed phase diagrams of the sulfate/nitrate/ammonium/water system are presented as a function of relative humidity at 298.15 K over the complete space of composition.