IHS ESDU Sound power radiation from isotropic plates. 00002

ESDU 00002 describes how vibrating plates radiate sound power by setting the surrounding fluid in motion, and it allows the estimation of the sound power radiated from an isotropic plate to a fluid with properties similar to those of air (low fluid loading). It covers two types of plate configurations: a single plate and a double plate (corresponding to a double wall construction). The ability of the single plate to radiate sound power is described by its radiation efficiency which depends on the properties of the plate and of the fluid, the boundary conditions of the plate and the nearby surrounding structure referred to as a baffle. Analytical expressions are given that allow the calculation of the radiation efficiency. A number of graphs enable these values to be corrected for the influence of the boundary conditions and the influence of the baffle. For real plate constructions the boundary conditions will be somewhere between simply-supported and clamped. An auxiliary program, ESDUpac A0002, allows the boundary conditions to be determined approximately from one or several measured resonance frequencies. For a double plate, the fluid in the gap between the plates will influence the sound power radiation and a theory different from that used for the single plate must therefore be employed. This theory is incorporated in the program, ESDUpac B0002, which allows the estimation of the radiated sound power from a double plate construction. Finally, analytical expressions are given from which SEA (Statistical Energy Analysis) coupling loss factors between fluids and plate structures may be calculated. The programs are provided with this Item. Full details of input and output formats are given and illustrated by worked examples.