Compressive spherical beamforming for localization of incipient tip vortex cavitation

Area of Science:

• Acoustics
• Fluid Dynamics
• Signal Processing

Background:

• Propeller tip vortex cavitation (TVC) generates distinct acoustic noises near the propeller tip.
• Accurate localization of these sparse acoustic events is crucial for understanding and mitigating cavitation.

Purpose of the Study:

• To develop and validate a compressive sensing (CS) method for localizing incipient propeller tip vortex cavitation (TVC) noise.
• To compare the performance of CS with traditional Bartlett spherical beamforming for cavitation source localization.

Main Methods:

• Formulating a sensing matrix for CS using spherical beamforming, treating initial TVC sound as a monopole source.
• Validating CS localization with known acoustic source measurements.
• Applying modified CS constraints, incorporating physical cavitation features, to enhance localization accuracy.

Main Results:

• CS accurately estimated source positions in controlled experiments.
• Cavitation localization using CS identified sources near the upper downstream propeller area with reduced ambiguity compared to Bartlett spherical beamforming.
• Modified CS constraints further suppressed ambiguity in TVC localization.

Conclusions:

• Compressive sensing offers a robust and accurate method for localizing propeller tip vortex cavitation noise.
• The developed CS approach, particularly with modified constraints, provides superior performance over conventional beamforming techniques for cavitation analysis.