Izvorni znanstveni članak
A LAGRANGIAN PARTICLE MODEL WITH CHEMICAL REACTIONS: APPLICATION IN REAL ATMOSPHERE
Stefano Alessandrini
; CESI RICERCA, Milano, Italy
Enrico Ferrero
; Università del Piemonte Orientale, Alessandria, Italy
Sažetak
In this work a lagrangian particle model able to account for simple chemical reactions between NO and O3 (Alessandrini
et al., 2007) has been improved in order to consider the photolysis of NO2. A system of chemical equations is numerically solved on
an eulerian grid, while the particles trajectories are moved in a lagrangian frame. The NOx emissions of a power plant in real
atmosphere, situated in a complex topography environment, have been considered as a test case. The meteorological model RAMS
has been applied to build the wind field together with the interface code MIRS to compute turbulence parameters, requested for the
dispersion simulations. The plume transitions over an air quality station, allowing for a comparison between the measured and
computed concentrations of all the reaction’s compounds (NO, NO2 and O3), have been simulated by the lagrangian particle model.
The simulated episodes refer to the diurnal time, when the ultraviolet radiation activates the NO2 photolysis making necessary the
model complete set of chemical equations. In order to reduce computational cost and improve the accuracy of the background O3
concentration representation, the concept of concentration deficit carried by the particles is proposed and tested. This new method
does not need to release a big amount of particles filling the whole domain, but only the inside plume particles should be accounted
for. Comparisons between NO/NO2’s concentrations ratio are presented in term of scatter plots and statistical indexes analysis. The
satisfactory results suggest that the model can be used in practical applications in real atmosphere also for regulatory purposes when
the NO2 concentration limits are imposed by the legislation.
Ključne riječi
Atmospheric dispersion; NO; chemistry model; Lagrangian Particle Model; photo-stationary equilibrium
Hrčak ID:
64248
URI
Datum izdavanja:
12.12.2008.
Posjeta: 1.003 *