Study of Numerical Diffusion in a Discrete-Sectional Model and Its Application to Aerosol Dynamics Simulation

Document Type

Article

Publication Date

1-1-1998

Abstract

The discrete-sectional model is an important tool used to study aerosol dynamics, although it suffers inherent numerical diffusion errors that are dependent on the model parameters including section spacing, numerically conserved aerosol property, and number of discrete sizes. An analytical evaluation of the errors due to the deviations of the derived aerosol properties in the sectional formulation and the interchange between discrete-size and sectional aerosols is carried out. The errors are larger if the difference in the aerosol property function index (ξ) between the derived and conserved properties is larger. Results of parametric studies are reported for condensation and coagulation systems. The results for condensation systems show that the υ-model is better than the n-model and the υ2-model in predicting the integral properties of the size distribution. However, the deviation in the results between the n-model, υ-model, and υ2-model reduces as the section spacing is decreased. A finite value of the geometric standard deviation (σg) is obtained for a specific section spacing and is independent of the chosen conserved aerosol property. The results for coagulation systems also show that the υ-model is better in predicting N, V, and υg, although the υ2-model is better in predicting the second volume moment, V2, and σg. The inclusion of a larger number of discrete sizes gives more precise description of aerosol dynamics for the molecular clusters, although the effect is rather insignificant for the number greater than 20. It is also found that the discrete formulation possesses numerical diffusion in simulating a condensation process. © 1998 Taylor & Francis Group, LLC.

Identifier

0032212785 (Scopus)

Publication Title

Aerosol Science and Technology

External Full Text Location

https://doi.org/10.1080/02786829808965576

e-ISSN

15217388

ISSN

02786826

First Page

359

Last Page

378

Issue

5

Volume

29

Grant

OCRC 94-4.13

Fund Ref

U.S. Department of Energy

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