Graduation Year


Document Type




Degree Name

MS in Mechanical Engineering (M.S.M.E.)

Degree Granting Department

Mechanical Engineering

Major Professor

David Murphy, Ph.D.

Committee Member

Andres E. Tejada-Martinez, Ph.D.

Committee Member

Rasim Guldiken, Ph.D.


Breathing, Concentration, Flow Pattern, Flowrate, OPS, Particle Size


It is important to understand the airborne transmission of infectious diseases due to the COVID-19 pandemic. Physical experiments were conducted to understand the dispersion of aerosols emitted from a mannequin simulator replicating human tidal breathing through the nose and mouth with and without a protective face mask in an enclosed space. Flow patterns are observed via high-speed visualization, and the concentration and size distribution of the particles is measured as a function of distance from the mannequin using an optical particle sizer. Masks were shown to effectively reduce the horizontal dispersion of aerosol for both mouth and nose breathing. Further, the masks were effective in decreasing the concentration of emitted aerosols and were particularly effective for the largest particles. The results provide insight into the dispersion of aerosol by breathing and into how masks may help contain that aerosol to prevent the spread of airborne diseases.