AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Novel 3D Numerical Simulations to Calculate the Capacitance of Nanoparticle Aggregates with Necking Effect and Loose Agglomerates
LEO N.Y. CAO, Jing Wang, Heinz Fissan, Max L. Eggersdorfer, David Y. H. Pui, University of Minnesota
Abstract Number: 175 Working Group: Engineered Nanoparticles: Emissions, Transformation and Exposure
Abstract The electrical capacitance of aerosol particles is an important property for particle research as electric charging is frequently used to characterize the particles, e.g.measurement of agglomerates by their charging properties (Wang et al. 2010, Shin et al. 2010). Few 3D numerical simulations for the capacitance of loose agglomerates with large amounts of primary particles have been done; studies calculating the capacitance of compact aggregates with necking effect are even more scarce. In this work, we model the capacitance of loose agglomerates and obtain the charge distribution on the agglomerates by using a minimum energy method (Brown & Hemingway, 1995) in three dimensions. Diffusion limited cluster-cluster agglomerates are generated with a fractal dimension around 1.8. The change in the capacitance of such compact aggregates with necking effect in a sintering process is also modeled in this study. The complete arbitrary shaped aggregate is divided into finite elements using a mesh and every element is treated as a primary particle. The approximation provides satisfactory results when the mesh number is sufficiently high. There is only a 2 percentage overestimation for a big sintered sphere compared to the theoretical results.