TY - GEN
T1 - Disturbance speed measurements in a circular jet via double focused laser differential interferometry
AU - Jewell, Joseph S.
AU - Hameed, Ahsan
AU - Parziale, Nicholaus J.
AU - Gogineni, Sivaram
N1 - Publisher Copyright:
© 2019 by German Aerospace Center (DLR). Published by the American Institute of Aeronautics and Astronautics, Inc.
PY - 2019
Y1 - 2019
N2 - Measurements and calculations of the phase speed of disturbances observed in turbulent jets of three diameters are made at speeds between 80 m/s and 300 m/s, via cross-correlation of signals from a double focused laser differential interferometer (D-FLDI). A consistent trend in correlation-derived disturbance propagation speeds is observed with varying jet velocity, and the strength of the correlation decreases as the jet is moved lat-erally through the interferometer away from the focus point. The correlation curves also collapse across varying jet velocities when normalized. The dual FLDI beams are im-aged and separation distances characterized using a beam profiler. Spectral density curves from the D-FLDI and hotwire anemometer at similar locations are compared. The effect of orienting FLDI bundles parallel with and at a 45° angle to the mean flow direction is assessed and shown to be minimal in terms of the disturbance velocity computed via cross-correlation.
AB - Measurements and calculations of the phase speed of disturbances observed in turbulent jets of three diameters are made at speeds between 80 m/s and 300 m/s, via cross-correlation of signals from a double focused laser differential interferometer (D-FLDI). A consistent trend in correlation-derived disturbance propagation speeds is observed with varying jet velocity, and the strength of the correlation decreases as the jet is moved lat-erally through the interferometer away from the focus point. The correlation curves also collapse across varying jet velocities when normalized. The dual FLDI beams are im-aged and separation distances characterized using a beam profiler. Spectral density curves from the D-FLDI and hotwire anemometer at similar locations are compared. The effect of orienting FLDI bundles parallel with and at a 45° angle to the mean flow direction is assessed and shown to be minimal in terms of the disturbance velocity computed via cross-correlation.
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U2 - 10.2514/6.2019-2293
DO - 10.2514/6.2019-2293
M3 - Conference contribution
AN - SCOPUS:85083943951
SN - 9781624105784
T3 - AIAA Scitech 2019 Forum
BT - AIAA Scitech 2019 Forum
T2 - AIAA Scitech Forum, 2019
Y2 - 7 January 2019 through 11 January 2019
ER -