一种根据声衰减系数估计尾流气泡数密度谱的迭代算法
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摘要
针对现有谐振估计法在实际应用中对水中气泡数密度谱的估算存在误差,从而无法得到准确的舰船气泡尾流或者海面风生气泡层的气泡数密度谱的问题,在谐振估计法的基础上提出了一种根据声衰减系数估算气泡数密度谱的迭代算法。根据模拟水中气泡分布的声衰减系数和Stanic在海水中的实测声衰减系数,对比分析了运用谐振估计法和提出的迭代算法对汽泡数密度谱的估算,结果表明:该迭代算法可有效消除谐振估计法的误差,可应用于对海面风生气泡层以及舰船尾流气泡数密度谱的研究。
In practical application, the commonly applied resonance estimation method is apt to cause errors in estimating the bubble number density spectra in water, thus the failure to obtain accurate number density spectra of the ship bubble wake and the wind-generated bubbles layer near sea surface. Given the deficiency of the existing method and for improvement′s sake, an iterative algorithm for estimating the bubble number density spectra based on the acoustic attenuation coefficient is proposed. On the basis of the attenuation coefficient of simulated bubble distribution in water and the attenuation coefficient measured by Stanic in the sea, and the results are compared by applying the conventional method and the algorithm proposed in this paper, respectively. The comparison verifies the accuracy of the iterative algorithm with effective elimination of the error caused by the resonant estimation method, and thus proves that the algorithm can be applied in the study of wind-generated bubbles layer near sea surface and the bubble population density spectra of ship wake.
In practical application, the commonly applied resonance estimation method is apt to cause errors in estimating the bubble number density spectra in water, thus the failure to obtain accurate number density spectra of the ship bubble wake and the wind-generated bubbles layer near sea surface. Given the deficiency of the existing method and for improvement′s sake, an iterative algorithm for estimating the bubble number density spectra based on the acoustic attenuation coefficient is proposed. On the basis of the attenuation coefficient of simulated bubble distribution in water and the attenuation coefficient measured by Stanic in the sea, and the results are compared by applying the conventional method and the algorithm proposed in this paper, respectively. The comparison verifies the accuracy of the iterative algorithm with effective elimination of the error caused by the resonant estimation method, and thus proves that the algorithm can be applied in the study of wind-generated bubbles layer near sea surface and the bubble population density spectra of ship wake.
引文
[1] MINNAERT M.On musical air-bubbles and the sounds of running water [J].Philosophical Magazine,1933,16:235-248.
[2] NDRC.Physics of Sound in the Sea [R].Wa-shington,DC:National Defense Research Committee Summary Technical Report Div.,1946:441-559.
[3] 乌立克 R J.工程水声原理 [M].洪申,译.北京:国防工业出版社,1972:277-293.
[4] MEDWIN H.Acoustical determinations of bubble-size spectra [J].Journal of the Acoustical Society of America,1977,62(4):1041-1044.
[5] STANIC S,KENNEDY E,BROWN B,et al.Broadband acoustic transmission measurements in surface ship wakes [C]// Proceedings of OCEANS 2007.Vancouver:OCEANS,2007:1-10.
[6] STANIC S,CARUTHERS J W,GOODMAN R R,et al.Attenuation measurements across surface-ship wakes and computed bubble distributions and void fractions [J].IEEE Journal of Oceanic Engineering,2009,34(1):83-92.
[7] 顾建农,张志宏,张晓晖.舰船远场尾流气泡分布特性的数值模拟 [J].光子学报,2007,36(8):1504-1509.GU Jian-nong,ZHANG Zhi-hong,ZHANG Xiao-hui.Numerical simulation of bubble distribution characters in ship′s far field wakes [J].Acta Photonica Sinica,2007,36(8):1504-1509.(in Chinese)
[8] 顾建农,田雪冰,张志宏,等.舰船主尺度参数对舰船气泡尾流几何特性的影响 [J].舰船科学技术,2012,34(1):6-10.GU Jian-nong,TIAN Xue-bing,ZHANG Zhi-hong,et al.The effect of the ship main scale parameter upon ship bubble wake geometry characters [J].Ship Science and Technology,2012,34(1):6-10.(in Chinese)
[9] 林巨,王欢,谢萍.基于声学方法的气泡分布和海表风速反演 [J].声学技术,2012,31(4):162-165.LIN Ju,WANG Huan,XIE Ping.Acoustic inversion of bubble size distribution and sea surface wind speed [J].Technical Acoustics,2012,31(4):162-165.(in Chinese)
[10] MEDWIN H.Acoustic fluctuations due to microbubbles in the near-surface ocean [J].Journal of the Acoustical Society of America,1974,56(4):1100-1104.
[11] TREVORROW M V.Measurements of near-surface bubble plumes in the open ocean with implications for high-frequency sonar performance [J].Journal of the Acoustical Society of America,2003,114(5):2672-2684.
[2] NDRC.Physics of Sound in the Sea [R].Wa-shington,DC:National Defense Research Committee Summary Technical Report Div.,1946:441-559.
[3] 乌立克 R J.工程水声原理 [M].洪申,译.北京:国防工业出版社,1972:277-293.
[4] MEDWIN H.Acoustical determinations of bubble-size spectra [J].Journal of the Acoustical Society of America,1977,62(4):1041-1044.
[5] STANIC S,KENNEDY E,BROWN B,et al.Broadband acoustic transmission measurements in surface ship wakes [C]// Proceedings of OCEANS 2007.Vancouver:OCEANS,2007:1-10.
[6] STANIC S,CARUTHERS J W,GOODMAN R R,et al.Attenuation measurements across surface-ship wakes and computed bubble distributions and void fractions [J].IEEE Journal of Oceanic Engineering,2009,34(1):83-92.
[7] 顾建农,张志宏,张晓晖.舰船远场尾流气泡分布特性的数值模拟 [J].光子学报,2007,36(8):1504-1509.GU Jian-nong,ZHANG Zhi-hong,ZHANG Xiao-hui.Numerical simulation of bubble distribution characters in ship′s far field wakes [J].Acta Photonica Sinica,2007,36(8):1504-1509.(in Chinese)
[8] 顾建农,田雪冰,张志宏,等.舰船主尺度参数对舰船气泡尾流几何特性的影响 [J].舰船科学技术,2012,34(1):6-10.GU Jian-nong,TIAN Xue-bing,ZHANG Zhi-hong,et al.The effect of the ship main scale parameter upon ship bubble wake geometry characters [J].Ship Science and Technology,2012,34(1):6-10.(in Chinese)
[9] 林巨,王欢,谢萍.基于声学方法的气泡分布和海表风速反演 [J].声学技术,2012,31(4):162-165.LIN Ju,WANG Huan,XIE Ping.Acoustic inversion of bubble size distribution and sea surface wind speed [J].Technical Acoustics,2012,31(4):162-165.(in Chinese)
[10] MEDWIN H.Acoustic fluctuations due to microbubbles in the near-surface ocean [J].Journal of the Acoustical Society of America,1974,56(4):1100-1104.
[11] TREVORROW M V.Measurements of near-surface bubble plumes in the open ocean with implications for high-frequency sonar performance [J].Journal of the Acoustical Society of America,2003,114(5):2672-2684.