The real acoustic power of a planar annular membrane radiation for axially-symmetric free vibrations

The real part of the acoustic power radiated by a planar annular membrane is considered for axially-symmetric free vibrations. The membrane is located in a planar, rigid baffle and radiate acoustic wave into a lossless and homogeneous fluid medium. Sinusoidal in time processes are examined. The real power is obtained as elementary form for high-frequency radiated waves.