Record Details
Field | Value |
---|---|
Title | An experimental investigation of aerosol coagulation in the shock tube |
Names |
Yun, Kyung Woo
(creator) Boubel, Richard W. (advisor) |
Date Issued | 1970-05-11 (iso8601) |
Note | Graduation date: 1970 |
Abstract | Ammonium chloride aerosols of submicron size generated by condensation and dispersion methods were treated, shortly after aerosol charging, with shock waves originating from diaphragm pressure ratios of up to 5.75. The fraction of the particulate matter remaining in suspension after a given time was measured as an indication of coagulation rate. The coagulation rate increased with increasing shock strength, but the rate of increase became gradually less as the shock strength increased. The initial particle concentration, the degree of dispersion, and the polydispersity were three major factors that influenced the rate of coagulation upon shock treatment. Organic vapors, i.e., acetone, carbon tetrachloride, and acetic acid, stabilized the aerosol but their presence enhanced the coagulation process upon shock treatment. The presence of water vapor resulted in a slight increase of coagulation rate, but the rate became relatively insensitive to increasing shock strength. Analysis of the particles showed substantial increases in size and a distinct change in their distribution after shock treatments. The experimental results could be explained in terms of increased particle collision probability. A model for the increased collision probability among particles in the shock tube was proposed. The total number of collision per unit volume per unit time was expressed in terms of particle size, particle number, and differential velocity acquired due to the differential acceleration of the particles. A vertically arranged shock tube was recommended for further investigation in order to minimize the problem of particle reentrainment. |
Genre | Thesis/Dissertation |
Topic | Aerosols |
Identifier | http://hdl.handle.net/1957/45811 |