Kimberly Pickett defended her MSEE final oral defense on Friday, May 6th

Particle Investigation in the Near-wake of an Elliptical Cylinder to Predict Exposure
Wind tunnel experiments were conducted to investigate size-specific particle concentrations in the near-wake of an elliptical cylinder serving as a human surrogate. An ultrasonic atomizer was placed downstream of the cylinder, inside the wake, to generate a poly-disperse liquid aerosol. Cascade impactors were used to determine the atomizer mass generation rate and aerosol concentrations for 6.3 – 9.7 mm oil particles. The mass generation rate was 7.2 mg/s, representing 67.2 % of the oil particles in the respirable size range. Particle concentrations were measured at locations representing the breathing, elbow, and hip regions.

The concentrations were expressed as dimensionless numbers relating concentration to the atomizer mass generation rate (mo), the height (H) and breadth (D) of the cylinder, and the freestream velocity (U). The dimensionless concentrations were 6.7, 65.5, and 4.3 for the breathing, elbow, and hip regions, respectively. For a worker facing downstream, a dimensionless breathing zone concentration of 7.0 is a reasonable estimate for respirable aerosols generated in the wake. The primary significance of the work is to extend a simple model of human exposure to aerosols and to provide a simple estimator for assessment and control studies.

Committee:

Academic/Research Advisor: Dr. Michael Flynn
Reader: Dr. David Leith
Reader: Dr. Leena Nylander-French

For further information please contact Rebecca Riggsbee Lloyd by email at Rebecca_Lloyd@unc.edu