Development of an aerosol size classifier. Progress report, May 31, 1977--January 31, 1978
The purpose of this research is to characterize the performance of rectangular slit virtual impactors. A mathematical description of two-dimensional jets of ideal fluid impinging upon a void has been developed using conformal mapping techniques. The analysis includes fluid deflecting plates of finite length inclined at arbitrary angles to the incident jet. Particle trajectories were simulated for various theoretically admissible instrument geometries. Salient features of the particle sizing effectiveness of such devices were determined for a range of void space openings h/w > 1 combined with jet to plate spacing s/w ranging from 0 to 2. Visual observations of two-dimensional jets impinging upon a void were conducted with a scaled-up water model. It was found that excess fluid flux into the void is minimized for a range of jet Reynolds numbers of 750 < Re < 1500. At smaller values of Re wall boundary layers interfere while at larger Re jet core instabilities develop. Modifications were made on an existing prototype virtual impactor to eliminate internal wall losses. Experiments are being performed using mono-dispersed 2.5 ..mu..m DOP particles to determine the magnitude of the internal losses and to fully characterize the instrument response.
- Research Organization:
- Illinois Univ., Urbana (USA)
- OSTI ID:
- 6801624
- Report Number(s):
- COO-4319-1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
47 OTHER INSTRUMENTATION
500200* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AEROSOLS
COLLOIDS
DESIGN
DISPERSIONS
MEASURING INSTRUMENTS
MEASURING METHODS
PARTICLE SIZE
SAMPLING
SIZE
SOLS
TRAJECTORIES