Date of Award
Master of Science (MS)
Civil, Environmental & Architectural Engineering
Experimental Investigation of Flow Field Patterns Resulting from Air Impingement by a Commercial Synthetic Jet Actuator on Wall Surfaces
The goal of this study was to characterize the flow field generated by a commercial, annular, multi-orifice synthetic jet actuator (SJA) as it impinged on a wall of varying surface textures. This experimental study determined the effect of SJA-to-wall distance on the airflow velocities near the impingement surface. The velocity profiles generated by the SJA were compared to those generated by a commercial axial computer fan (ACF) on smooth and rough surfaces. The results suggest that an SJA-to-wall distance of 215 mm had the greatest reduction on the peak airflow velocities, while an SJA-to-wall distance of 315 mm resulted in a velocity dampening effect furthest (225 mm) from the wall surface. Both the ACF and high-surface roughness resulted in increased turbulence at the wall surface. Increased surface roughness correlated to a decrease in the distance of the wall dampening effect.
Effect of Annular, Multi-Orifice Synthetic Jet Actuators on the Photocatalytic Degradation Rate of Nitrogen Dioxide (NO2)
The effect of airflow velocities generated by an annular, multi-orifice synthetic jet actuator (SJA) and an axial computer fan (ACF) on the rate of photocatalytic degradation of nitrogen dioxide (NO2) by a titanium dioxide (TiO2)-doped reactive surface was experimentally studied in a closed chamber. The impact of flow characteristics generated by the SJA and ACF, namely surface velocity and velocity distribution across the reactor surface, on the removal rates was investigated herein. The results demonstrate that the use of active flow devices (SJA or ACF) enhanced the removal rate of NO2 compared to ambient passive (control) conditions. However, increases in air velocity did not enhance the removal rate of NO2. The highest removal rate (k=0.0013 min-1) occurred when the SJA was located 315 mm from the reactor surface. This distance corresponded to a uniform surface velocity of approximately 0.1 m/s across the surface. A similar uniform surface velocity of approximately 0.1 m/s, when produced by the ACF, resulted in a lower removal rate (k=0.0011 min-1) compared to the passive case. Thus, the unique flow characteristics of the SJA, in conjunction with its location at the optimized distance from the reactor, resulted in the greatest enhancement of the reduction of NO2 by the TiO2 reactive surface.
Mauney, Denise Catherine, "Experimental Study of Active Flow on a Photocatalytic Material for Air Quality Applications" (2016). Civil Engineering Graduate Theses & Dissertations. 59.