Cubic spline interpolation-based time-domain equivalent source method for modeling transient acoustic radiation

Abstract Transient acoustic radiation from an arbitrarily-shaped source is modeled using a cubic spline interpolation-based time-domain equivalent source method. In the method, the cubic spline interpolation function is introduced to approximate the equivalent source strengths in the time domain for establishing the relationships between the acoustic quantities in the field, the normal acceleration on the source surface and the equivalent sources, and the least-squares solution of the equivalent source strengths at each time step is determined by an iterative solving process with the singular value decomposition technique. The proposed method has the abilities of calculating the acoustic quantities directly in the time domain and applying to arbitrarily-shaped sources. Numerical examples of calculating the transient acoustic fields from a baffled planar piston and an impulsively accelerating sphere demonstrate that the proposed method can model the transient acoustic radiation very well. The experimental results also further verify the validity of the proposed method.