首页   按字顺浏览 期刊浏览 卷期浏览 High-frequency backscattering enhancements by thick finite cylindrical shells in water ...
High-frequency backscattering enhancements by thick finite cylindrical shells in water at oblique incidence: Experiments, interpretation, and calculations

 

作者: Scot F. Morse,   Philip L. Marston,   Gregory Kaduchak,  

 

期刊: The Journal of the Acoustical Society of America  (AIP Available online 1998)
卷期: Volume 103, issue 2  

页码: 785-794

 

ISSN:0001-4966

 

年代: 1998

 

DOI:10.1121/1.421200

 

出版商: Acoustical Society of America

 

数据来源: AIP

 

摘要:

Impulse response backscattering measurements are presented and interpreted for the scattering of obliquely incident plane waves by air-filled finite cylindrical shells immersed in water. The measurements were carried out to determine the conditions for significant enhancements of the backscattering by thick shells at large tilt angles. The shells investigated are made of stainless steel and are slender and have thickness to radius ratios of 7.6% and 16.3%. A broadband PVDF (polyvinylidene fluoride) sheet source is used to obtain the backscattering spectral magnitude as a function of the tilt angle (measured from broadside incidence) of the cylinder. Results are plotted as a function of frequency and angle. These plots reveal large backscattering enhancements associated with elastic excitations at high tilt angles, which extend to end-on incidence in the coincidence frequency region. Similar features are present in approximate calculations for finite cylindrical shells based on full elasticity theory and the Kirchhoff diffraction integral. One feature is identified as resulting from the axial (meridional ray) propagation of the supersonica0leaky Lamb wave. A simple approximation is used to describe circumferential coupling loci in frequency-angle space for several surface waves. The resulting loci are used to identify enhancements due to the helical propagation of the subsonica0−Lamb wave.

 

点击下载:  PDF (341KB)



返 回