AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
Monte Carlo Simulations of Particle Formation Processes
GREGOR KOTALCZYK, Ivan Skenderović, Frank Einar Kruis, University Duisburg-Essen
Abstract Number: 436 Working Group: Aerosol Physics
Abstract We discuss the application of Monte Carlo (MC) simulation techniques for the description of typical particle production processes. The discussed modelling techniques encompass the decomposition of a precursor, which leads to the formation of a metallic vapour. Different temperature profiles (especially cooling rates) lead to a drastic increase of a supersaturation and thus to the onset of the nucleation of novel particles as well as their subsequent growth due to condensation and coagulation. The evaporation of particles has also to be taken into account in certain simulation scenarios, especially in those, in which temperature profiles (originating from turbulent carrier gas flows) describe an increase of the temperature after the nucleation took place and thus to the formation of unstable particles (i.e. whose diameter is smaller than the Kelvin diameter).
In a first part, we give a quick overview of the applied simulation techniques, which couples stochastic discrete events (for the coagulation and nucleation) with continuous processes (such as condensation, evaporation and precursor decomposition). We validate the MC method by comparison with the discrete-sectional method. The demanding simulation scenario incorporating all of the process discussed above poses special requirements not only on the MC method but also on the discrete-sectional method. We show the requirements (gird settings for the sectional methods, parameters for the MC simulations) for a correct description of the process.
In a second part, we discuss the application of the method on typical particle production processes for various materials (Fe, Ag, Cu, etc.). Special interest is given to the correct description of the nucleation process: several nucleation theories exist in the literature, which result in nucleation rates, which differ in several orders of magnitude. We propose a numerical methodology, which allows the identification of experimental conditions for the identification of the correct nucleation theory.