Reconstruction of nonstationary sound fields based on a time domain angular spectrum method

Area of Science:

• Acoustics
• Signal Processing
• Computational Physics

Background:

• Nonstationary sound fields pose challenges for traditional acoustic analysis.
• Accurate reconstruction of dynamic sound fields is crucial for applications in noise control and structural health monitoring.

Purpose of the Study:

• To develop a real-time method for reconstructing nonstationary sound fields.
• To provide a stable and accurate approach for analyzing time-varying acoustic phenomena.

Main Methods:

• A time domain angular spectrum method is proposed, expressing the sound field as a superposition of plane wave bases.
• The method utilizes an impulse response function incorporating propagating and evanescent waves.
• Discretization of time convolution and Tikhonov regularization enable step-by-step reconstruction.

Main Results:

• The proposed method allows for real-time reconstruction of nonstationary sound fields.
• Numerical simulations and experimental validation with unsteady and impacted plates demonstrate feasibility.
• The non-recursive nature ensures stable reconstruction, and Tikhonov regularization aids in accurate plane wave strength estimation.

Conclusions:

• The time domain angular spectrum method is effective for reconstructing nonstationary sound fields.
• The approach offers advantages in real-time analysis and stability compared to existing methods.
• Further investigation into numerical parameters can optimize reconstruction accuracy.