Nonlinear photophoretic response of submicrometer coated aerosol particles to electromagnetic radiation

摘要: A numerical method, including dual Monte Carlo sampling, has been developed for simulation of the photophoretic force acting on an illuminated coated aerosol particle. At low light intensity, order solar constant, response system (photophoretic force, velocity) to beam is linear. However, at high intensity strong nonlinear dependence evaporation rate and reradiation temperature in boundary conditions expression can cause significant deviation from linear response. In simulated theoretical model photophoresis, mass, momentum, energy fluxes particle surface were obtained “free molecule” regime distribution heat sources within was calculated according extension electromagnetic theory scattering concentric spheres (A. L. Aden M. Kerker, J. Appl. Phys. 22, 1242, 1951). addition sampling before (M. Sitarski Atmos. Sci., press) we applied external Newton iteration condition volatile Test computations carried out two-layered particles accumulation mode (0.16 μm radius) atmospheric aerosols corresponding altitude 10 km. The consist spherical soot cores with shells dirty ice. effect ice sublimitation taken into account these calculations. two assumed radii, 0.09 0.15 μm, internal sphere correspond minimum maximum press), respectively. present computer study shows model. values luminous intensities 106 mW/cm2 are several times lower than estimations based extrapolation former results intensities.