To identify azimuthal acoustic modes in cylindrical ducts, multiple sensors must be mounted at different azimuthal locations. For large-scale, expensive facilities or testing campaigns, such as engine testing, access points can be limited and must be chosen with great care amongst a host of other competing instrumentation and operational needs. This paper introduces a methodology to determine the optimal sensor locations, defined as the locations that minimize the variance of the estimated amplitude of azimuthal eigenmodes, for a given number of sensors and candidate acoustic modes . Given that access may not always be possible at these optimal locations, the same formulation also quantifies the tradeoffs with nonoptimal sensor locations. We present explicit results for optimal sensor locations for identifying a single mode, as well as illustrative computed results for optimal locations to identify multiple modes. For identifying a single mode, it is shown that the optimal placements decrease the uncertainty of the estimated wave amplitudes by and that of the estimated pressure by . We also present a table summarizing optimal locations for and various combinations of the first three azimuthal modes.
Optimal Sensor Placement for Azimuthal Acoustic Modes in Cylindrical Ducts
AIAA Journal ; 60 , 6 ; 3874-3883
2022-02-15
10 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Natural frequencies and modes of cylindrical polygonal ducts
Online Contents | 1993
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