AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Aerosol Mixing in Concentric Jets
MATTHEW BROWN, Suresh Dhaniyala, Clarkson University
Abstract Number: 378 Working Group: Instrumentation and Methods
Abstract A large number of aerosol instruments rely on detailed knowledge of aerosol-flow interaction to accurately count and size particles. In the DMA, the locational distribution of particles at the introduction to sheath flow is one of the critical factors in the accurate sizing of particles. High-resolution sizing in the DMA requires particles to be in a narrow set of streamlines when introduced at the outer cylinder. The mixing of the aerosol and sheath flows in the DMA may, however, spread particles into a broader set of streamlines, limiting the highest possible instrument resolution. In our study, we experimentally investigate the fundamental processes of laminar shear flow interaction using a particle-laden and clean flow in double concentric jets to better understand the flow field and resulting particle dispersion inside the DMA. The experimental results suggest that there is inherent mixing of jets even under highly laminar flow and the extent of mixing is strongly dependent on the ratio of velocities of the two flows. The experimental setup, obtained results, and their implications in limiting the performance of existing aerosol instruments will be discussed.