共查询到17条相似文献,搜索用时 514 毫秒
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介绍了一种带障板宽波束宽带纵振动换能器。通过将纵振动换能器的纵振动模态和前盖板弯曲振动模态有效耦合来达到拓宽换能器工作频带的目的;并提出利用反声障板边界结构大幅度增大发射波束宽度的方法。利用有限元软件分析了其在水中的特性。分析结果表明,通过纵弯模态耦合方式可有效拓宽换能器的频带宽度;通过障板在纵振动换能器中的应用可有效调节纵振动换能器的波束特性,从而实现宽波束的目的。实际制作该换能器并测试了其在不同情况下的性能,测试结果表明:有限元分析结果跟实验测量结果吻合。在9.5~18 kHz的频率范围内实现了发送电压响应起伏不超过3 dB的宽带工作;在11、12、13、14 kHz,实现了120°~160°的宽波束。 相似文献
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《中国新技术新产品》2017,(8)
本文讨论了一种具有上半空间指向性的水声发射换能器的结构,采用半液腔压电圆管换能器实现了上半空间指向性,在换能器结构中采用吸声锥形障板加反声障柱的方法,实现换能器的垂直向上的窄波束指向性。同时也提高了测量装备在边收边发方式下的声隔离度,有效抑制了收发换能器间的声串漏。通过对实物测试,系统声学收发隔离效果达到35d B以上,该换能器结构设计的有效性得到了验证,并将在装备研制中得到应用。 相似文献
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本文给出带障板的水听器指向性图的表示式,并与实测值进行了比较;阐述了高静水压下声障板的反声性能。水听器指向性的理论模型与实测图(基元因子)相当吻合,为基阵的布阵设计提供了理论依据。 相似文献
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Sergey V. Sorokin 《Composite Structures》2000,48(4):969-230
A problem of forced vibrations of a sandwich plate submerged in a fluid (an acoustic medium) is formulated as a coupled problem of structural acoustics. Two-dimensional (plane) formulation relevant to cylindrical bending of a plate is explored. Dynamics of a sandwich beam (a sandwich plate in cylindrical bending) is described in the framework of the sixth-order theory of multi-layered plates. Asymptotic analysis of the dispersion polynomial is performed in the low frequency and the low module limits for an isolated infinitely long beam. Green's functions for flexural vibrations are obtained analytically and thus explicitly contain the principal parameters of beam's composition. Forced vibrations of a fluid-loaded beam in a rigid baffle are considered. Both the interaction between an acoustic medium and a plate and the interaction between a plate and its boundaries are described by boundary integral equations assembled in a two-level system. Eigenfrequencies of a fluid-loaded beam are detected by maximum of the radiated acoustic power. A semi-analytical sensitivity analysis of the objective function selected as a radiated acoustic power to the parameters of beam's composition is performed. 相似文献
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Harmonic ultrasound fields through layered liquid media 总被引:2,自引:0,他引:2
Li Y Chen Q Zagzebski J 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2004,51(2):146-152
Harmonic field generation through a layered liquid media is studied experimentally and theoretically. Lateral and axial beam profiles of the fundamental to the 4th harmonic component of the field from a focused, 19-mm diameter transducer were measured using a calibrated hydrophone in a water tank. Measurements were performed before and after the insertion of a cylindrical phantom containing vegetable oil. A frequency domain numerical solution to the "KZK" equation was used to calculate the beam profile, taking into account the acoustic properties of the medium and phantom. Effects of nonlinear propagation, diffraction, attenuation, and reflection are included in the calculation. Agreement within 5% was obtained between measurements and theoretical predictions throughout the mid- and far-field of the transducer for both the uniform path and the layered media. Measurements also were carried out using an unfocused transducer as a receiver. The shape of the axial beam profile using this receiver agreed very well with the theoretical prediction using the "KZK" equation, after accounting for phase variations over the finite-sized detector in the calculated field. 相似文献
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圆柱阵换能器具有水平全向的优势,已广泛应用在水声探测领域。文章研究了一款宽带圆柱阵,利用匹配层技术拓宽圆柱阵阵元的带宽,通过有限元仿真优化单个换能器阵元带宽、发送电压响应和阻抗等参数。同时通过仿真以阵元错位密集方式形成圆柱阵,对阵元的个数及排列方式进行仿真优化,制作了一款宽带圆柱阵并进行了测量,圆柱阵直径为400 mm,高度为435 mm,圆柱阵的工作频段为20~30 kHz,频带内起伏3 dB,最大发送电压响应为160.5 dB,圆柱阵-3 dB水平波束宽度为360°。 相似文献
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Toda M 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2008,55(7):1653-1659
This paper investigates acoustic wave radiation from cylindrical polyvinylidene fluoride (PVDF) film mounted inside a concentric wall with a small air gap. In such a structure, propagation is allowed only in the gap between the film and the wall surface, and the wave propagates in the axial direction of the cylinder. The radiation impedance of the cylindrical transducer inside the concentric wall has been calculated using a one-dimensional propagation model. After calculating the mechanical impedance of the cylindrical PVDF film, the generated acoustic wave has been calculated as a function of frequency with various air gaps between the PVDF film and the wall. It has been found that the excited acoustic wave becomes stronger for a narrower air gap and shows a maximum at a specific air gap. This phenomenon has been explained as the match between the transducer impedance and the radiation impedance of the air gap. When the gap is too small, the radiation impedance exceeds the transducer's mechanical impedance, the acoustic wave radiation decreases with the decreasing gap, and the resonance frequency increases due to loading by the imaginary part of the excessive radiation impedance. All these theoretical results have been experimentally confirmed. 相似文献
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Ultrasonic beam steering characteristics for linear phased array transducers are simulated numerically by visualizing the full-field acoustic pressure field of the waves radiated from a linear phased array transducer. The influences of various transducer parameters on the beam steering properties are studied, including number of elements, inter-element spacing, element size, frequency of the transducer and the steering angle. In addition, the effects of these parameters on the near field characteristics are investigated by analyzing the acoustic pressure profile in the steering direction. The simulation results agree well with the analytical solutions which are valid only in the far field. A suggested scheme for optimal transducer design is presented. 相似文献