Directional characteristic of a circular membrane vibrating under The effect of a force with uniform surface distribution

In this paper. the acoustio pressure of a ciroular membrane is analysed
on the assumption that the distance between the field point and the membrane
is muoh longer, both in terms of its linear dimensions and the wavelengths
radiated. It was 8.8l:!umed that the membrane woo exoited to induced harmonic
vibration - including nOnresonance one - by a force with uniform surface
distribution. The membrane was placed in a rigid, planar ba.:Hle, and the gas
medium, into whioh it radiated, was 108s1088. Numerical examples of the directional
characteristic were represented graphically.