Acoustic characterization of panel materials under simulated ocean conditions using a parametric array source.

Area of Science:

• Acoustics
• Materials Science
• Ocean Engineering

Background:

• Evaluating underwater acoustic performance of materials is critical for naval and marine applications.
• Simulating realistic ocean conditions in a laboratory setting presents significant technical challenges.

Purpose of the Study:

• To describe and validate a laboratory technique for evaluating the underwater acoustic performance of panels.
• To enable measurements of reflection loss and transmission loss under simulated ocean conditions.

Main Methods:

• Utilized a parametric array as a sound source within a test vessel simulating ocean depths (up to 700 m) and temperatures (2-35°C).
• Employed an acoustic filter to create a source-free measurement region, simplifying the process.
• Determined reflection loss and transmission loss at frequencies from a few kHz to 50 kHz.

Main Results:

• Successfully validated the technique on test objects with predictable acoustic behavior.
• Demonstrated the method's capability by presenting experimental results for test panels under hydrostatic pressures up to 2.8 MPa.
• The parametric array facilitated wideband measurements with short pulses, minimizing diffraction effects.

Conclusions:

• The described technique provides a reliable method for evaluating underwater acoustic panel performance in a controlled laboratory environment.
• The method is suitable for a range of frequencies and hydrostatic pressures relevant to oceanographic applications.
• Further research can build upon this technique to explore a wider range of materials and conditions.