Transient Models of a Photophoretically Filtering Structure in the Stratosphere

Abstract

The stratosphere has very little convection and tends to trap any dust and gases that enter this region from the atmosphere. This study suggests how dust and particles can be filtered from the stratosphere by a 2-plated parallel-walled infinite rotatable, levitating vertical/horizontal channel (preferably) perforated with holes which have pockets on the cooler upper wall for collecting particles. A movement of particles by light called photophoresis, is caused by the radiative warming layer of a sandwich structure. Collisions of gases with surface of structure and thermal gradients between the two thin plates will also deflect particles. Equations of momentum and energy are solved using an implicit finite difference scheme while exact solutions are presented for steady state dimensionless velocity, concentration and temperature for a fully developed flow. Heat and mass transfer characteristics of parameters like time are displayed graphically. Combined photophoretic and thermophoretic effect on water particles  is negligible when compared to soot or dust particles Sc=600.