Acoustic baffle for high-pressure service, modular design

An acoustic array for application to submerged hull surfaces comprises:

• an acoustic baffle for attachment to the hull to reduce the transmission of shipboard noise, said acoustic baffle including layers of viscoelastic material disposed between layers of rigid material;
• an acoustic conditioning module connected to said acoustic baffle for coherently reflecting incident acoustic signals so that the reflected acoustic signals reinforce the incident acoustic signals, said conditioning module including spaced coverplates, a plurality of spacer elements extending between said coverplates to form sealed chambers therebetween and a plurality of damping elements positioned in said chambers and connected to one of the coverplates;
• and
• an outer layer connected to said acoustic conditioning module, said outer layer contains a plurality of hydrophone units and said outer layer is formed of material having an impedance which approximates the impedance of seawater;
• where said rigid layers are bonded to the opposite faces of the viscoelastic layers to form a plurality of modular units, and said modular units being bonded together with flexible bond layers so that a flexible bond layer is disposed between the rigid layers of the adjacent modular units;
• and
• wherein the viscoelastic layers are formed with a plurality of open cells arranged in a predetermined pattern with the pattern of open cells in adjacent viscoelastic layers being offset from each other so that the load bearing portions of one viscoelastic layer overlap the open cells of the adjoining viscoelastic layer.