Radiated power and radiation efficiency of a point driven panel

Abstract

The partial radiation efficiency from a line-driven panel was previously defined and investigated by the authors [‘‘Partial radiation efficiency of line-driven panels,’’ J. Sound Vib. 144, 71–86 (1991)]. In the present paper, the counterpart to the previous work is presented. It is shown that the radiation efficiency, like the partial radiation efficiency, is dependent on the mechanical damping in the panel; and again, the efficiency increases with increase in the mechanical loss factor in the panel. Also, the dependence of the radiation efficiency on fluid loading is analogous to that of the partial radiation efficiency described in the previous work. In this paper, in addition, the radiated power as a function of frequency is investigated. It is shown that the radiated power appropriately diminishes with an increase in the mechanical damping. This result, in contrast, shows the fallibility of the conclusion that ‘‘a higher radiation efficiency implies, without further qualifications, more radiated power.’’ The results of computer experiments are cited in support of the various aspects in the paper.