AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Prediction of Balloon-Borne Impactor Collection Efficiency at Different Altitudes
Gyuho Kim, SE-JIN YOOK, Kang-Ho Ahn, Hanyang University
Abstract Number: 156 Working Group: Instrumentation and Methods
Abstract For the analysis of particles airborne in the atmosphere, it is important to collect those particles efficiently. Inertial impactors are commonly used for sampling atmospheric aerosol particles. The inertial impactors have advantages in miniaturization owing to simple geometry and easy operation, and therefore are appropriate for being loaded on balloons. However, impactor cut-off size can vary according to altitude, since the atmospheric pressure and temperature change with increasing altitude. In this study, a numerical simulation technique was developed for predicting collection efficiency of inertial impactors, and validated at low as well as normal pressure levels by comparing the numerically obtained collection efficiencies with the experimental data of previous studies. Balloon-borne inertial impactors, having cut-off sizes of 1, 2.5, and 10 micrometers, were designed. A simple equation was suggested for predicting the sampling flow rate required for keeping the impacotor cut-off sizes constant at different altitudes. When the sampling flow rate was adjusted as predicted, the cut-off sizes of the balloon-borne inertial impactors were estimated to remain unchanged even at different altitudes in the troposphere.
This work was supported by the Korea Ministry of Environment as "The Eco-innovation project."
ysjnuri@hanyang.ac.kr