Measurements of Aeroacoustic Sound Sources in Turbulent Jets

Time Resolved PIV for Space-Time Correlations in Hot Jets

“…At the NASA Glenn Research Center (GRC), PIV has been extensively used to characterize the first and second order statistical properties of both cold and hot jet flows from internally and externally mixed nozzles in the Nozzle Acoustic Test Rig (NATR) [1] and from simple and chevron equipped nozzles in the Small Hot Jet Acoustics Rig (SHJAR) [2]. These PIV measurements provide an extensive and accurate database of 1 st and 2 nd order statistics for validation of Computational AeroAcoustic codes (CAA).…”

Dynamic measurement of temperature, velocity, and density in hot jets using Rayleigh scattering

“…TR-PIV data were acquired at the lower temperature flow conditions (set point 23) in the same facility prior to this test (Wernet 2007) and are included here for comparison with the Rayleigh measurements. Conventional 10 Hz PIV data were available at set point 46 flow conditions (Bridges and Wernet 2003). Both the nozzle flow and ambient air were seeded in the PIV work to achieve velocity measurements in the core as well as the mixing layer.…”

“…The density measured by PMT 5 and the temperature estimate from MLE analysis were used to determine the local pressure using the ideal gas law. Temporally-resolved velocity data previously acquired using TR-PIV at 10 kHz data rate and conventional 10 Hz PIV data were compared to the Rayleigh data (Wernet 2007, Bridges andWernet 2003). Reynolds-Averaged Navier-Stokes (RANS) CFD predictions from the work of Kenzakowski (2007a, 2007b) were also compared with mean and rms velocity and temperature values estimated by the Rayleigh technique.…”

Progress Toward Improving Jet Noise Predictions in Hot Jets

“…Comparisons were made with available PIV data collected at the SHJAR facility (ref. 4) at NASA Glenn Research Center.…”