Effects of shear waves on boundary-coupled vector sensors

Area of Science:

• Acoustics
• Solid Mechanics
• Oceanography

Background:

• Acoustic vector sensors are crucial for underwater acoustic field measurements.
• Understanding sensor response at fluid-solid interfaces is vital for accurate data interpretation.
• The acoustic properties of solid media can significantly influence wave propagation and sensor readings.

Purpose of the Study:

• To investigate how the acoustic properties of a solid medium affect an acoustic vector sensor at a water-solid boundary.
• To analyze the normal and tangential components of the acoustic vector field at this interface.
• To identify potential processing challenges arising from these interactions.

Main Methods:

• Theoretical analysis of acoustic wave propagation at a fluid-solid interface.
• Examination of acoustic vector sensor response, considering both normal and tangential velocity components.
• Modeling the influence of shear waves in the solid medium.

Main Results:

• The tangential velocity component is significantly affected by shear waves in the solid.
• Amplitude and phase discontinuities are observed across the water-solid boundary.
• These discontinuities can create mismatches in vector sensor components, hindering coherent processing.

Conclusions:

• The acoustic properties of solid media, particularly shear effects, introduce complexities in acoustic vector sensor measurements at fluid-solid boundaries.
• These findings have direct implications for the design and data processing of ocean bottom- and hull-mounted acoustic systems.
• Mitigation strategies for discontinuities may be necessary for reliable underwater acoustic sensing.