The Numerical Computation of Radiation Impedance of Zonal Arrays on a Hard Prolate Spheriodal Baffle

摘要

This report consists of two parts. In the first part the mechanical radiation impedance between 'tesseral section' sound sources in an acoustically hard prolate spheriodal baffle is analyzed and formulas derived for calculating the impedance in terms of prolate spheriodal wave functions. The particular case of the interaction between zonal sound sources is treated in detail. In the second part a complete numerical study is made of the interaction between eight zones on prolate spheriodal baffle 2.3 lambda long having a radius alpha at the equator such that ka nearly equals 3. The zones have an axial height of lambda/10 and are spaced lambda/10 units apart. Theoretical radiation impedance interaction coefficients are calculated, and tables are presented of mutual and self impedances of all eight zones. Theoretical acoustic beam patterns are calculated and plotted for the condition of equal zonal surface velocities. (Author)