A Simplified Algorithm for Impedance Calculation of Arbitrarily Shaped Radiators

It is well known that a computationally efficient model for calculation of radiation impedance of an arbitrarily shaped piston has been developed. We simplify the proposed algorithm by using geometric characteristics and intrinsic relationship between the analytic expressions. As an example, the method accuracy is illustrated and the radiation impedance of a right-angled triangular piston is calculated. The numerical results are in good agreement with that obtained directly by the quadruple integral method.     

A Fast Field Scheme for the Parametric Sound Radiation from Rectangular Aperture Source

A virtual complex source approach has been developed to calculate numerically the ultrasound field generated by a rectangular planar source with high efficiency. The sound field can be treated as the resultant sound pressure from a set of complex virtual sources located at a complex distance, and then by exploiting the integrability of Gaussian function, a substantial analytical reduction to single integral is derived for the second-order field of the sum-, difference-frequency and second harmonic components. The validity of this fast field scheme is confirmed by comparison of numerical results and the experimental data published previously.