3C-4 A Fast Nearfield Method for Calculating Pressures Generated by Rectangular Pistons with Polynomial Apodization

A fast nearfield method for calculating the pressure generated by a polynomial apodized rectangular piston is obtained. The fast method is based on the instantaneous impulse response given by Scarano et al. A trigonometric transform of the integrand is performed and the order of integration is exchanged to obtain the 1D integral for the apodized FNM. Comparisons between the 1D polynomial apodized FNM and the Rayleigh-Sommerfeld integral show that the 1D polynomial apodized FNM is 18.58, 81.17, and 205.11 times faster than the Rayleigh-Sommerfeld integral for 10%, 1%, and 0.1% peak normalized errors, respectively.