AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Application of Combined Particle Charging Mechanism to Computational Fluid Dynamics
RAVI SANKAR VADDI, Igor Novosselov, University of Washington
Abstract Number: 648 Working Group: Aerosol Physics
Abstract Exposure to complex environmental agents such as ultrafine particulate matter derived from combustion sources or engineered nanomaterials can trigger or exacerbate diseases, including asthma and cardiovascular disease. Compact electrostatic collectors can be used to collect ultrafine particles based on mobility to assess environmental exposure. Devices with diffusion charging are most widely used in the air quality monitoring systems and are usually large and difficult to use. The simpler way is, corona discharging which combines both field and diffusion charging and it is easy to implement in a low-cost compact device.
This work primarily focuses on developing a numerical model for particle charging using combined diffusion and field charging and particle transport in the electrical field. The numerical model is carried out by coupling the interactions between fluid mechanics, electrostatics, particle charging and particle transport. Unsteady, 2-D axisymmetric computational fluid dynamics modelling was used to develop the particle charging and particle transport model. The combined field-diffusion particle charging model is dependent on the ion concentration through which a particle passes by and the particle exposure time to ions. The results from the model are compared with the experimental results of needle to ring ionizer and wire-and-tube collector. The effect of flow rate and electric field on the particle charging is evaluated and compared with experiments.