弾性振動殻 : 音響放射系の有限要素シミュレーション : スピーカ・システム特性計算への応用例

抄録

We have pointed out the feasibility of the finite element technique on electro-acoustic system analysis, and demonstrated the application to piezoelectric transducer problems. The present work is concerned with another coupled elastic structure-acoustic medium system, that is, a direct-radiator speaker model in which a vibrating shell backed by a closed cavity is to radiate sound into semi-infinite acoustic space. The model is two-dimensional or axisymmetric, and its shape and acoustic cavity profile could be arbitrary. The computer simulation program is developed based on finite element approach and some calculations of the driving-point impedance of the shell under various acoustic loading conditions and far-field sound pressure characteristics are demonstrated. The effects of the coupling to the cavity and the case of a so-called vented enclosure are also discussed. Comparison with a real system and verification of the approach are not given, which would be reported in due course.