| 摘要 |
FIELD: machine building.SUBSTANCE: module comprises an external acoustically transparent envelope featuring one- or multi-layer version made of metal or polymer material or from a combined laminated structure of dissimilar structural materials shaping a closed formed independent vessel with the porous sound-absorbing material placed into the inner cavity. A form of the external acoustically transparent envelope is presented primarily in regular geometrical figures of volumetric cavity elements, a thickness of the wall of the external acoustically transparent envelope does not exceed 3 mm, its structural construction material corresponds primarily to a continuous air-tight layer of elastic polymer film or metal foil or air-blasted perforated layer of elastic polymer film or metal foil or air-blasted fibrous layer of non-woven fabric or woven fabric, or a perforated layer of metal or polymer material, or the combined multi-layer combined conjunctions thereof. A volume of every stand-alone fractured sound-absorbing element is located primarily in a range of V=4.2×(10?10) m, while a density of filling a cavity of the closed formed stand-alone vessel amounts to ?=10?655 kg/m.EFFECT: improving acoustic convenience due to improved noise-suppressing efficiency in the extended frequency range.33 cl, 47 dwg |
