Experimental and numerical investigation of aerosol scavenging by sprays /

Bibliographic Details
Main Author: Goldmann, Andrew S.
Other Authors: Hassan, Y. A. (Thesis advisor)
Format: Thesis eBook
Language:English
Published: [College Station, Tex.] : [Texas A&M University], [2011]
Subjects:
Online Access:Link to OAK Trust copy
Description
Abstract:In the event of a hypothetical nuclear reactor accident, the combination of plant design, operator training, and safety procedures result in low level risks to the general public; however, an additional offsite consequence mitigation system has the potential to substantially decrease the amount of radioactive material that could reach a population zone in a postulated accident scenario. An experimental and numerical investigation of airborne particulate scavenging by water sprays was conducted as part of a consequence mitigation study. Previous researchers have experimentally studied the removal of aerosols by sprays, but only in a confined region. The experiment conducted in this research used an expansive region where sprays could significantly affect the flow fields in the spray region. Experimentation showed an expected trend of higher particle collection efficiencies with increased residency time within the spray region, with the highest average overall collection efficiency found to be 70.6±-3.2% at an air flow rate of 0.53 m/s and a water flow rate of 0.84 gpm. This general trend is expected because a longer residency time leads to an increased probability of particle-drop interaction. Collection efficiencies were also found to increase with increased particle number density. The numerical investigation was done using a deterministic method and a Monte Carlo method. Each model shows promise based on theoretical limitations of drop size for the experimental conditions. The theory demonstrates that particle-drop relative velocity as well as the sizes significantly affect collection efficiency. An alternative study was conducted to determine the collection efficiency of non-wettable particles since the dust used in the experiment is hydrophobic. Computational Fluid Dynamics (CFD) models were also performed to determine the flow fields that developed within the experiment spray region and substantiate differences in the experimental and numerical models.
Item Description:"Major Subject: Nuclear Engineering"
Title from author supplied metadata (automated record created 2011-02-28 11:02:00).
Electronic resource.
Physical Description:1 online resource.
Bibliography:Includes bibliographical references.