Youngjin Seo
I joined the Aerosol Technology Laboratory (ATL) in January 2003. From then until August 2004, I conducted two projects for my Masters degree. The two projects I worked on were the “Mixing” project and the “Inlet” project. The objective of the “Mixing” research was to design mixing elements for HVAC ducts to achieve the Environmental Protection Agency (EPA) limit for a single representative sample from a turbulent flow through HVAC ducts and optimize the placement of airborne radioactivity monitors. Regarding the “Inlet” project, an inlet is the device through which samples are extracted from the ambient environment. The effectiveness of an inlet is dependent upon both the size of the aerosol and the wind speed in the ambient environment. In addition, inlets need to prevent precipitation, debris, and insects from entering a bioaerosol sampler while also permitting the penetration of aerosol particles in the size range of interest (Aerodynamic Diameter: 10 µm). The objective of the research was to design an inlet of atmospheric aerosol sampler that would meet the above requirements. Since August 2004, I have been conducting research, for my dissertation, regarding “Bioaerosol Sampling Cyclone”. Cyclones are used by the military to facilitate the detection of biological weapons in the particle size of interest (Aerodynamic Diameter: 1 µm) and by the postal service as an Anthrax detection system. The existing cyclone needed to be upgraded because of several problems such as a recirculation ring and liquid bypass. In addition, the concept of the cyclone is to utilize liquid to collect particulates effectively. What if the cyclone were to be out in the field in the state of Minnesota in January? Any liquid in the cyclone would be frozen, which would make the cyclone malfunction. In order to prevent this problem, a study of turbulent heat transfer for cold temperature operation was conducted, both numerically and experimentally. In addition, a smaller version of the cyclone is being developed that can be operated at one-twelfth of the air flow rate that is used for the main sampling cyclone. Numerical studies are being conducted using commercial software, employing turbulent mixing and cyclones. All of the above projects are being sponsored by the U.S. Army RDECOM.
Comparison of two cyclones in terms of Aerosol-to-Hydrosol efficiency, Left: Old cyclone, Right: New cyclone
Heater and temperature sensor configuration (on the new cyclone) for experimental validation of heat transfer simulations
Temperature Transitions (Incoming Air Temperature: -25 deg C). All the data were obtained from the above cyclone
Placement of heaters and temperature sensors (upgraded) on cyclone assembly
•Master Thesis
“Degree of Mixing Downstream of Rectangular Bends and Design of
an Inlet for Ambient Aerosol.” Texas A&M University, December 2004.
•Paper
o Hu, S., Seo, Y., McFarland, A., Haglund, J. Turbulent Heat Transfer
Study on a Bioaerosol Sampling Cyclone. In Progress.
o Seo, Y., McFarland, A., Ortiz, C., O’Neal, D. (2006). Mixing in a Square
and a Rectangular Duct Regarding Selection of Locations for Extractive
Sampling of Gaseous Contaminants. Health Physics 91(1):47-57.
•Conference
o Seo, Y., Haglund, J., McFarland, A. (2006). Experimental Study of Bioaerosol
Sampling Collector. 2006 AAAR, Minneapolis, MN.
o Seo, Y., Hu, S., Thien, B., King, M., Haglund, J., McFarland, A. (2006).
A Wetted-Wall Bioaerosol Sampling Cyclone. 2006 Scientific Conference
on Obscuration and Aerosol Research, Aberdeen, MD.
o Phull, M., Seo, Y., Moncla, B., Thien, B., Haglund, J., McFarland, A.
(2005). Design and Characterization of Two Wetted-Wall Cyclones for Bioaerosol
Collection. 2005 Scientific Conference on Obscuration and Aerosol Research,
Aberdeen, MD.
o Seo, Y., Ortiz, C., Hari, S., McFarland, A. (2003). Inlets for Bioaerosol
Sampling System. 2003 Joint Scientific Conference on Chemical & Biological
Defense Research, Towson, MD.
Email: yjseo@neo.tamu.edu