Directional Radiation Pattern Design Using Structural-Acoustic Coupling

This paper presents a design of the directional radiation pattern by using the structural-acoustic interaction. For this purpose, prediction of the pressure distribution of the field points and radiation pattern of the structural-acoustic coupling system is shown. In order to get a strong coupling, coupled system that has a finite space and a semi-infinite space separated by two flexible walls and an opening is selected. A volume interaction can be occurred in structure boundary and a pressure interaction can be happened in the opening boundary. The coupled system is maximized the radiation power on the main axis and minimized the side lobe level

Design of Directional Structural-Acoustic Coupled Radiator in Wave Number Domain

A design procedure using spatial Fourier transform is presented for a structural-acoustic coupled radiator that can emit sound in the desired direction with high power and low side lobe level. The design procedure consists of three steps. Firstly, the structural-acoustic coupled radiator is chosen to obtain strong coupling between structural vibration and acoustic pressure. The radiator is composed by two spaces which are separated by a wall. Spaces can be categorized as reverberant finite space and unbounded semi-infinite space, and the wall are composed of two plates and an opening. The velocities on the wall are predicted. Secondly, directivity and energy distribution of radiator are predicted in wave number domain using spatial Fourier transform. Finally, optimal design variables are calculated using a dual optimal algorithm. Its computational example is presented including the directivity and resulting pressure distribution using proposed procedure

The Effects of the Boundary Shapes on the Structural-acoustic Coupled System

If a wall separates the bounded and unbounded spaces, then the wall's role in transporting the acoustic characteristics of the two spaces is not well defined. In this paper, we attempted to see how the acoustic characteristical of two spaces are really affected by the spatial characteristics of the wall. In order to understand coupling mechanism, we choose a finite space and a semi-infinite space separated by the flexible or rigid wall and an opening. A volume interaction can be occurred in structure boundary and a pressure interaction can be happened in the opening boundary. For its simplicity, without loosing generality, we use rather simplified rectangle model instead of generally shaped model. The source impedance is presented to the various types of boundaries. The distributions of pressure and active intensity are also presented at the cavity and structure-dominated modes. The resulting modification, shifts of mode1 frequencies and changing of standing wave patterns to satisfy both coupled boundary conditions and governing equations, are presented

High sensitivity compression type accelerometer and Method for assembling the same

압전체의 크기 및/또는 형태의 제한없는 완충층을 이용한 압축형 가속도 센서가 개시된다. 상기 압축형 가속도 센서는, 질량체, 상기 질량체가 내측에 설치되게 안착 공간이 형성되고, 상기 질량체와 접촉되며 부피의 크기가 서로 다른 압전 단결정이 설치되는 하우징, 및 상기 하우징과 결합되는 베이스를 포함하는 것을 특징으로 한다

압전 박막형 트랜스듀서 효율 향상 연구

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공정개선을 통한 PBLG/PMMA 복합 압전체 성능 향상

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파라메트릭 어레이를 위한 다공진 트랜스듀서 설계

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An experimental study of noise source identification and level reduction of a washing machine

학위논문(석사) - 한국과학기술원 : 기계공학과, 1991.2, [ iv, 50 p. ]한국과학기술원 : 기계공학과

압전 초소형 초음파 트랜스듀서의 대역폭 향상 연구

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심해 적용을 위한 압전 두께 모드형 하이드로폰의 설계 및 평가

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