AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Solving the General Dynamic Equation for Nucleation, Surface Growth, and Coagulation, using the Nodal Method
JAMES CORSON, George Mulholland, Michael Zachariah, University of Maryland
Abstract Number: 122 Working Group: Aerosol Physics
Abstract We present a MATLAB-based code for solving the general dynamic equation using the nodal method, where particles exist at discrete size nodes instead of in bins, as in the sectional method. The MATLAB version of NGDE is based on an earlier version of the code written in C but includes several notable improvements. These improvements include a dynamic timestep that significantly decreases code execution time and enhances numerical stability, a more modular structure whereby the various physics packages are consolidated in subroutines (as opposed to appearing multiple times in different sections of the code) to simplify code maintenance, and a post-processing feature that generates static figures as well as animations that show changes in the particle size distribution in time. The post-processing tool also incorporates a Mie scattering calculation to illustrate changes in the extinction and scattering coefficients with the changes in size distribution. Results for the particle size distribution are in excellent agreement with exact solutions (where available) and with the previous iteration of the code. This MATLAB-based NGDE code and post-processing routine can be a useful teaching tool because the code is relatively simple, yet it incorporates the important physics of particle nucleation, surface growth, and coagulation. The following examples will be given: coagulation of an initially monodisperse aerosol, surface growth of a monodisperse aerosol, and the full GDE (nucleation, surface growth, and coagulation) for condensing aluminum vapor.