Affiliations: School of Mechanical, Industrial and Manufacturing
Engineering, Oregon State University, 204 Rogers Hall, Corvallis, Oregon
97331-6001, USA. E-mail: [email protected]
Abstract: Spatially varying surface temperature oscillations in a nominally
steady reattaching slot jet at a Reynolds number (Re) of 5000 are analyzed
using Proper Orthogonal Decomposition (POD) for two nozzle-to-surface
spacings, and three exit openings of the nozzle. The surface temperature data
in these experiments were recorded using infrared thermography at a frequency
of 20 Hz along two selected lines on the impingement surface corresponding to
geometrically similar and dissimilar regions within the reattachment curtain.
The magnitude of temperature oscillations were found to increase with an
increase in exit opening for the larger nozzle spacing. The POD analysis
results indicate that a majority of the temperature flucutations are well
captured by 15 dominant modes. In many cases, the three dominant modes
accounted for approximately 60 percent of the variance in surface temperature
fluctuation.