共查询到17条相似文献,搜索用时 109 毫秒
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以纵振模式中高频压电换能器有效工作面形状、面积为变量,研究其收发指向性随工作面积权加权的变化规律。参考浅海多波束声呐接收阵元设计要求,用SYSNOISE软件仿真计算了几种不同工作面形状换能器的接收指向性图,选用一种接收阵元的仿真参数制作了换能器实物,样品测试与仿真结果较一致。 相似文献
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在基于多模振动的超宽带声基阵的研究中,需要了解该阵同单模振动相比的电声效率的变化。为此,必须要对宽带声阵的空间增益有一个正确的可信的估算。本文就是按实测的声阵指向性图通过拟合指向性函数,然后经数学处理得到空间增益,再经简单换算得到电声效率,以便正确评估匹配层宽带换能器基阵的性能。 相似文献
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针对大型低频换能器指向性难以测量的问题,提出了一种基于四元十字阵的测量方法以获取大型低频换能器的指向性。利用到达四元十字阵阵元的时延差信息,结合双曲面交汇法对换能器进行定位,并根据四元十字阵阵元测得的声信号实现大型低频换能器指向性的测量;对定位算法进行理论仿真,设计并进行了湖上试验以测量模拟声源的指向性;对湖上试验测量数据进行计算分析,并与模拟声源在消声水池中的测量结果进行比较,两者-3 dB波束开角的测量结果相差在10%以内。此方法可以用于低频换能器指向性的测量。 相似文献
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提出了一种基于激光测振技术和边界元方法计算声源指向性的新方法,利用该方法对一弯曲圆盘换能器空气中以及水中的辐射指向性进行了计算。首先利用激光测量方法得到了弯曲圆盘换能器的表面振动分布,然后利用边界元方法推算其辐射的指向性,并与瑞利积分方法计算得到的换能器的指向性进行了对比。 相似文献
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随着换能器谐振频率的降低,其尺寸一般会增大,现有的测量方法对其指向性的测量越来越困难,而且换能器在实船安装前后性能会发生变化。文章提出了一种基于三维立体水听器阵列的开阔水域下换能器指向性实船校准方法。利用超短基线定位和坐标转换确定待校准换能器与水听器阵列的位置与方向,并通过水听器阵的接收声压数据绘制换能器的指向性图。在湖上试验时分别使用标准测量法和实船校准法测量换能器的指向性,并对5 kHz和2.5 kHz频率下的实验数据进行对比分析,测试结果表明:-3 dB波束宽度误差分别为4.2%和7.4%,均满足水声测量误差低于10%的要求,证明了实船校准法的可行性和有效性。 相似文献
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阐述用近场法(赫姆霍兹积分法)在换能器和声呐阵的近场进行测量并推算它们的远场指向性的基本原理。以实例说明,用不同的近场测量面测量圆柱形声呐阵的指向性,能够得到令人满意的结果。 相似文献
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带障板圆柱阵的指向性特性 总被引:1,自引:1,他引:0
本文给出了通用性较强的适于工程计算的带障板接收圆柱阵空间指向性函数的数学模型;稍作限制,此模型也适用于发射圆柱阵。同时给出了具有不同障板形式的圆柱阵指向性函数的表达式。最后用一实例,证明了本文提出的数学模型的实用性。 相似文献
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Arthur C. Clay Shi-Chang Wooh Lawrence Azar Ji-Yong Wang 《Journal of Nondestructive Evaluation》1999,18(2):59-71
The influence of several geometric parameters of linear phased arrays was studied. A systematic approach using an automated testing assembly was used to assess the steering performance of the array in a solid medium. In addition to calibrating the transducer with respect to its steering accuracy, this arrangement provided a detailed study of the effects of steering angle, number of elements, inter-element spacing and array aperture on the beam directivity. The experimental results show good agreement quantitatively with the predicted steering characteristics. 相似文献
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Garner G Steer MB 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2012,59(4):776-784
Traditional parametric arrays are produced by a second-order nonlinear interaction between two primary ultrasonic tones that are close in frequency, resulting in a difference tone that is in the audio band. This article presents a parametric array produced by a third-order nonlinear interaction between two primary ultrasonic tones that are distantly spaced in frequency such that one tone is approximately the second harmonic of the other. The result is a third-order lower intermodulation (IM3) tone in the audio band with greater directivity and lower side lobe amplitude than comparable second-order fields. Measurements are presented that compare the directivity of 1-, 2-, and 4-kHz difference tones to that of 1-, 2-, and 4-kHz IM3 lower tones. Furthermore, a cascaded second-order approach for N-element transducer arrays is used to model third-order scattering with good agreement between measurement and theory. 相似文献
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Shi C Gan WS 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2011,58(2):437-450
In the past two decades, the majority of research on the parametric loudspeaker has concentrated on the nonlinear modeling of acoustic propagation and pre-processing techniques to reduce nonlinear distortion in sound reproduction. There are, however, very few studies on directivity control of the parametric loudspeaker. In this paper, we propose an equivalent circular Gaussian source array that approximates the directivity characteristics of the linear ultrasonic transducer array. By using this approximation, the directivity of the sound beam from the parametric loudspeaker can be predicted by the product directivity principle. New theoretical results, which are verified through measurements, are presented to show the effectiveness of the delay-and-sum beamsteering structure for the parametric loudspeaker. Unlike the conventional loudspeaker array, where the spacing between array elements must be less than half the wavelength to avoid spatial aliasing, the parametric loudspeaker can take advantage of grating lobe elimination to extend the spacing of ultrasonic transducer array to more than 1.5 wavelengths in a typical application. 相似文献
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《IEEE sensors journal》2008,8(11):1755-1762
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一般国内估算声呐作用距离时,平面阵指向性指数采用《实用声呐工程》的公式进行估算,但可能因公式推导时近似项选取问题,实际应用时发现该估算结果与实际计算值相差较大,国内外现有的其他平面阵指向性指数估算公式也存在如误差较大或表达式复杂、理论过程不明确等问题。针对国内外存在诸多平面阵指向性指数估算公式的估算精度大小不一的问题,文章进行了理论推导、改进和比较分析,使估算值更接近真值。文章还进行了相应的仿真分析和验证,结果表明本文的估算公式更接近真实值,并适用于圆柱阵等其他曲面阵等基阵的指向性指数估算。 相似文献