Method of determining the effective scattering cross section

Abstract

This paper considers the method of determining the effective acoustical scattering cross section (Seff) for an object of arbitrary form or determining the contribution of its part into Seff. The method is based on the determination of transfer coefficients by direct and reciprocal methods and calculation of Seff using the equation (without the diagram coefficient): Seff(Ω)/S∼〈Krec2(Ω)〉F×〈K dir2 (Ω)〉V, where S is the total square of the object, Ω is the angular position of the point in the external field, 〈Krec2(Ω)〉F is the root-mean-square value of the transfer coefficient linking the force F with the acoustic field, which is determined by the reciprocal method, 〈Kdir2(Ω)〉V is the root-mean-square value of the transfer coefficient linking the vibrovelocity V on the surface of the object with the acoustic field, which is determined by the direct method. The root-mean-square values of K are determined over the necessary number of points on the surface of the object. The method proposed shows high noise protection in the experimental investigations. This method allows one to use a powerful generator and vibrator to increase the signal/noise ratio. The experimental results are presented.