空间有源声吸收的理论研究

THEORETICAL RESEARCH ON ACTIVE SOUND ABSORPTION IN SPACE

理论研究了空间有源声吸收问题．从声场和能量的角度出发，通过理论分析，本文给出了空间声场中单极子、偶极子和四极子所能达到的最大消声量及为此而须满足的条件，并且分析了其吸声性能，指出了各自的空间吸声方位角．通过分析高阶次级源结构，概括了一维多极子源的吸声条件和吸声性能。由于一维多极子源结构存在空间吸声方位角，本文发展了多维次级源结构，可对空间内任何方向入射来的声波进行声吸收。分析中没有涉及初级声源，因此所得结果具有普遍性。

in this paper,Active Sound Absorption is theoretically studied.The maxiumsound absorption and the optimum radiating conditions of monopole,dipole and quadrupole areobtained by theoretical analysis.Their absorption angles are also given.The absorption condition and performance of one dimensional multi poles source are colligated by investigating thestructure of npoles source.Because of the existing of absorption angle of one dimensionalsources, the multidimensional secondary sources are developed,which can absorb the soundemited from any direction in space.