TY - GEN
T1 - Reflected shock tunnel noise measurement by focused differential interferometry
AU - Parziale, N. J.
AU - Shepherd, J. E.
AU - Hornung, H. G.
PY - 2012
Y1 - 2012
N2 - A series of experiments is conducted where a quantitative non-intrusive optical technique is used to investigate disturbances in the free-stream of T5, the free-piston driven reflected shock tunnel at Caltech. The optical technique, focused laser differential interferometry (FLDI), measures fluctuations in density. In the test matrix, reservoir enthalpy is varied while the reservoir pressure is held fixed. The results show the perturbations in density are not a strong function of the reservoir enthalpy. During one experiment, exceptional levels of noise were detected; this unique result is attributed to non-ideal operation of the shock tunnel. The data indicate that rms density fluctuations of less than 0.75% are achievable with attention to tunnel cleanliness. In addition, the spectral content of density fluctuation does not change throughout the test time.
AB - A series of experiments is conducted where a quantitative non-intrusive optical technique is used to investigate disturbances in the free-stream of T5, the free-piston driven reflected shock tunnel at Caltech. The optical technique, focused laser differential interferometry (FLDI), measures fluctuations in density. In the test matrix, reservoir enthalpy is varied while the reservoir pressure is held fixed. The results show the perturbations in density are not a strong function of the reservoir enthalpy. During one experiment, exceptional levels of noise were detected; this unique result is attributed to non-ideal operation of the shock tunnel. The data indicate that rms density fluctuations of less than 0.75% are achievable with attention to tunnel cleanliness. In addition, the spectral content of density fluctuation does not change throughout the test time.
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U2 - 10.2514/6.2012-3261
DO - 10.2514/6.2012-3261
M3 - Conference contribution
AN - SCOPUS:85015892522
SN - 9781600869334
T3 - 42nd AIAA Fluid Dynamics Conference and Exhibit 2012
BT - 42nd AIAA Fluid Dynamics Conference and Exhibit 2012
T2 - 42nd AIAA Fluid Dynamics Conference and Exhibit 2012
Y2 - 25 June 2012 through 28 June 2012
ER -