Spherical-wave expansions of piston-radiator fields

Area of Science:

• Acoustics
• Wave Propagation
• Numerical Methods

Background:

• Understanding sound fields from transducers is crucial in acoustics.
• Circular piston radiators are common sources, but their near-field analysis can be complex.
• Existing methods may lack efficiency for detailed near-field computations.

Purpose of the Study:

• To develop a computationally efficient method for analyzing the continuous-wave fields of a circular piston radiator.
• To provide accurate representations of the sound field in the near-field region.
• To derive closed-form expressions for multipole coefficients.

Main Methods:

• Derivation of spherical-wave expansions for continuous-wave fields.
• Application to a circular piston radiator in a rigid baffle.
• Development of recursive methods for evaluating multipole coefficients.

Main Results:

• Simple spherical-wave expansions valid throughout the illuminated half-space were obtained.
• The derived expansions facilitate efficient numerical computation, particularly in the near-field.
• Closed-form expressions for multipole coefficients were successfully derived and can be evaluated recursively.

Conclusions:

• The developed spherical-wave expansions offer an efficient and accurate approach for near-field acoustic analysis of circular piston radiators.
• Recursive evaluation of multipole coefficients simplifies numerical implementation.
• This method enhances the understanding and simulation of acoustic fields in practical applications.