Open AccessComplex acoustic intensity of normal modes in Pekeris waveguide and its application
Author(s) -
Yu Yun,
Hui Jun-Ying,
Anbang Zhao,
Sun Guo-Cang,
Teng Chao
Publication year - 2008
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.57.5742
Subject(s) - sound intensity , acoustics , intensity (physics) , acoustic wave , physics , acoustic source localization , sound power , point source , transducer , waveguide , optics , underwater acoustics , sound speed gradient , phase (matter) , underwater , sound (geography) , geology , oceanography , quantum mechanics
The vector field of normal modes in Pekeris waveguide is studiedand the expression of horizontal and vertical complex acoustic intensity are proposedespecially their characteristics are analyzed in this paper. For the single order modethe form in the horizontal direction is traveling wavethe corresponding complex acoustic intensity is activeand the vertical form is standing wavethe corresponding complex acoustic intensity is reactive. But for the multi-order modeeither the horizontal or vertical complex acoustic intensity has both active and reactive component because of the interference between the normal modes. Only the active component can transport energybut the reactive component also carries important information of sound field. The numerical analysis shows thatfor the very low frequency sound field of point sourcethe sign of the active component of horizontal complex acoustic intensity and the reactive component of vertical complex acoustic intensity changed regularly with the change of the depth of acoustic sourceso the target depths can be classified by comparing with a critical depth when the receiving transducer is placed in appropriate depthsespecially the active component of horizontal complex acoustic intensitycan be used to tell whether the sound source is near the surface or underwater. Further morethe phase angle of complex acoustic intensity is discussed and its distribution regularities are analyzed.