-
摘要
实际介质普遍具有黏弹性, 波在传播过程中常伴有能量的耗散、相位畸变和频带变窄等, 对于含有液体和气体的介质, 衰减现象尤为突出. 由于经典的波动理论未考虑介质的黏弹性效应, 基于完全弹性假设的模拟波场和实际传播特征之间的差异明显, 波动理论在工程技术中的应用效果还有提升的空间. 在岩石物理中, 品质因子Q是量化地震衰减强度的参数, 为了研究波在地下介质中的传播规律, 本文从常Q理论出发, 在黏弹性介质频散关系中, 利用多项式拟合和Taylor展开法将频率的分数阶转化为整数阶, 进而推导了时间域复数形式的地下黏弹性介质波动方程. 该近似处理避免了频散关系经域转换后出现分数阶时间微分项, 能有效地降低计算成本. 最后, 采用有限差分法联合伪谱法对均质模型实现了波场的数值模拟, 验证了方程的有效性.-
关键词:
- 黏弹性介质 /
- 波动方程 /
- 数值模拟 /
- 伪谱法
Abstract
The energy of wavefield is gradually attenuated in all real materials, which is a fundamental feature and more obvious in the media containing liquid and gas. Because the viscosity effect is not considered in the classical wave theory, the actual wavefield is different from the simulated scenario based on the assumption of complete elasticity so that the application of wavefield does not meet the expectations in engineering technology, such as geophysical exploration. In the rock physics field, the well-known constant-Q theory gives a linear description of attenuation and Q is regarded as independent of the frequency. The quality factor Q is a parameter for calculating the phase difference between stress and strain of the media, which, as an index of wavefield attenuation behavior, is inversely proportional to the viscosity. Based on the constant-Q theory, a wave equation can be directly obtained by the Fourier transform of the dispersion relation, in which there is a fractional time differential operator. Therefore, it is difficult to perform the numerical simulation due to memory for all historical wavefields. In this paper, the dispersion relation is approximated by polynomial fitting and Taylor expansion method to eliminate the fractional power of frequency which is uncomfortably treated in the time domain. And then a complex-valued wave equation is derived to characterize the propagation law of wavefield in earth media. Besides the superiority of numerical simulation, the other advantage of this wave equation is that the dispersion and dissipation effects are decoupled. Next, a feasible numerical simulation strategy is proposed. The temporal derivative is solved by the finite-difference approach, moreover, the fractional spatial derivative is calculated in the spatial frequency domain by using the pseudo-spectral method. In the process of numerical simulation, only two-time slices, instead of the full-time wavefields, need to be saved, so the demand for data memory significantly slows down compared with solving the operator of the fractional time differential. Following that, the numerical examples prove that the novel wave equation is capable and efficient for the homogeneous model. The research work contributes to the understanding of complex wavefield phenomena and provides a basis for treating the seismology problems.-
Keywords:
- viscoelastic media /
- wave equation /
- numerical simulation /
- pseudo-spectral method
作者及机构信息
Authors and contacts
文章全文 : translate this paragraph
参考文献
[1] Yang P, Brossier R, Metivier L 2018 SIAM J. Sci. Comput. 40 B1101 Google Scholar
[2] Chen H, Zhou H, Yao Y 2020 Geophysics 85 S169 Google Scholar
[3] Keating S, Innanen K 2020 Geophysics 85 R397 Google Scholar
[4] Zhang, W, Shi Y 2019 Geophysics 84 S95 Google Scholar
[5] Liu H P, Anderson D L, Kanamori H 1976 Geophys. J. Int. 47 41 Google Scholar
[6] Emmerich H, Korn M 1987 Geophysics 52 1252 Google Scholar
[7] Zhu T, Carcione J M, Harris J M 2013 Geophys. Prospect. 61 931 Google Scholar
[8] Kjartansson E 1979 Geophys. Prospect. 84 4737
[9] Carcione J M 2008 Geophysics 74 T1
[10] Carcione J M, Cavallini F, Mainardi F, Hanyga A 2002 Pure Appl. Geophys. 159 1719 Google Scholar
[11] Lu J F, Hanyga A 2004 Geophys. J. Int. 159 688 Google Scholar
[12] Podlubny I 1999 Fractional Differential Equations (California: Academic Press) pp270−217
[13] Yang J, Zhu H 2018 Geophys. J. Int. 215 1064 Google Scholar
[14] Chen X W, Zhang R C, Mei F X 2000 Acta Mech. Sin. 16 282 Google Scholar
[15] Dorodnitsyn V, Kozlov R 2010 J. Eng. Math. 66 253 Google Scholar
[16] 方刚, 张斌 2013 物理学报 62 154502 Google Scholar
Fang G, Zhang B 2013 Acta Phys. Sin. 62 154502 Google Scholar
[17] Li H X, Tao C H, Liu C, Huang G N, Yao Z A 2020 Chin. Phys. B 29 064301 Google Scholar
[18] 周聪, 王庆良 2015 物理学报 64 239101 Google Scholar
Zhou C, Wang Q 2015 Acta Phys. Sin. 64 239101 Google Scholar
[19] Zhang Z J, Wang G J, Harris J M 1999 Phys. Earth Planet. Inter. 114 25 Google Scholar
[20] 董良国, 马在田, 曹景忠 2000 地球物理学报 43 856 Google Scholar
Dong L G, Ma Z T, Cao J Z 2000 Chin. J. Geophys 43 856 Google Scholar
[21] 孟路稳, 程广利, 张明敏, 尚建华 2017 海军工程大学学报 29 57
Meng L W, Cheng G L, Zhang M M, Shang J H 2017 J. Naval Univ. Eng. 29 57
[22] 杜启振, 刘莲莲, 孙晶波 2007 物理学报 56 6143 Google Scholar
Du Q, Liu L, Sun J 2007 Acta Phys. Sin. 56 6143 Google Scholar
[23] 唐春安 1997 岩石力学与工程学报 4 75
Tang C A 1997 Chin. J. Rock Mech. Eng. 4 75
[24] Carcione J M 2014 Wave Fields in Real Media (Amsterdam: Elsevier Science) p75
[25] Chen W, Holm S 2004 J. Acoust. Soc. Am. 115 1424 Google Scholar
[26] Carcione J M 2010 Geophysics 75 A53 Google Scholar
施引文献
-
图 1 拟合曲线 (Q = 30)
Fig. 1. Fitting curve (Q = 30).
图 2 数值模拟模型
Fig. 2. Numerical simulation model.
图 3 600 ms波场快照
Fig. 3. Wavefield snapshot at 600 ms.
图 4 不同时刻的1维波场
Fig. 4. One dimensional wavefield at different times.
图 5 波场记录
Fig. 5. Wavefield record.
图 6 记录频谱
Fig. 6. Record spectrum.
图 7 组合波场
Fig. 7. Combined wavefield.
图 8 部分波场
Fig. 8. Part wavefield.
图 9 复杂模型波场模拟 (a) 速度模型; (b) 0.3 s波场; (c) 0.4 s波场; (d) 0.5 s波场
Fig. 9. Wavefield simulation for the complex model: (a) Velocity; (b) wavefield at 0.3 s; (c) wavefield at 0.4 s; (a) wavefield at 0.5 s.
表 1 不同Q值拟合系数
Table 1. Fitting coefficients of different Q values.
Q 5 10 20 30 60 100 5000 a1 0.8144 0.9081 0.9545 0.9698 0.9850 0.991 0.9998 a2 58.452 30.728 15.662 10.499 5.276 3.1716 0.0636 a3 –2078.2 –1133.1 –587.58 –396.08 –200.14 –120.57 –2.4255 两个鬼故事残联工作职责适合女孩起名带米的字穿越之黎锦的农家日常超能陆战队百度云中国叙利亚比分适合猪小孩起名用的字起名字大全起名称大全情趣内衣店猪年男宝宝起什么乳名为合作社起名老黄历生辰八字起名字啊15寸是多少厘米何子起名男孩威风凛凛进行曲神界危机作弊版2020年宝宝起名字传奇起什么名字爆率高男孩起小名洋气的姓秦取名起名大全段伟伦特种兵之火凤凰44张姓双胞胎起名性姿势34式图片公司起名有哪些注意事项品牌起名生成器新美铝笔记本电脑开不了机怎么办霹雳战元史之动机风云刁是什么男孩起名和谐校园少年生前被连续抽血16次?多部门介入两大学生合买彩票中奖一人不认账让美丽中国“从细节出发”淀粉肠小王子日销售额涨超10倍高中生被打伤下体休学 邯郸通报单亲妈妈陷入热恋 14岁儿子报警何赛飞追着代拍打雅江山火三名扑火人员牺牲系谣言张家界的山上“长”满了韩国人?男孩8年未见母亲被告知被遗忘中国拥有亿元资产的家庭达13.3万户19岁小伙救下5人后溺亡 多方发声315晚会后胖东来又人满为患了张立群任西安交通大学校长“重生之我在北大当嫡校长”男子被猫抓伤后确诊“猫抓病”测试车高速逃费 小米:已补缴周杰伦一审败诉网易网友洛杉矶偶遇贾玲今日春分倪萍分享减重40斤方法七年后宇文玥被薅头发捞上岸许家印被限制高消费萧美琴窜访捷克 外交部回应联合利华开始重组专访95后高颜值猪保姆胖东来员工每周单休无小长假男子被流浪猫绊倒 投喂者赔24万小米汽车超级工厂正式揭幕黑马情侣提车了西双版纳热带植物园回应蜉蝣大爆发当地回应沈阳致3死车祸车主疑毒驾恒大被罚41.75亿到底怎么缴妈妈回应孩子在校撞护栏坠楼外国人感慨凌晨的中国很安全杨倩无缘巴黎奥运校方回应护栏损坏小学生课间坠楼房客欠租失踪 房东直发愁专家建议不必谈骨泥色变王树国卸任西安交大校长 师生送别手机成瘾是影响睡眠质量重要因素国产伟哥去年销售近13亿阿根廷将发行1万与2万面值的纸币兔狲“狲大娘”因病死亡遭遇山火的松茸之乡“开封王婆”爆火:促成四五十对奥巴马现身唐宁街 黑色着装引猜测考生莫言也上北大硕士复试名单了德国打算提及普京时仅用姓名天水麻辣烫把捣辣椒大爷累坏了
-
[1] Yang P, Brossier R, Metivier L 2018 SIAM J. Sci. Comput. 40 B1101 Google Scholar
[2] Chen H, Zhou H, Yao Y 2020 Geophysics 85 S169 Google Scholar
[3] Keating S, Innanen K 2020 Geophysics 85 R397 Google Scholar
[4] Zhang, W, Shi Y 2019 Geophysics 84 S95 Google Scholar
[5] Liu H P, Anderson D L, Kanamori H 1976 Geophys. J. Int. 47 41 Google Scholar
[6] Emmerich H, Korn M 1987 Geophysics 52 1252 Google Scholar
[7] Zhu T, Carcione J M, Harris J M 2013 Geophys. Prospect. 61 931 Google Scholar
[8] Kjartansson E 1979 Geophys. Prospect. 84 4737
[9] Carcione J M 2008 Geophysics 74 T1
[10] Carcione J M, Cavallini F, Mainardi F, Hanyga A 2002 Pure Appl. Geophys. 159 1719 Google Scholar
[11] Lu J F, Hanyga A 2004 Geophys. J. Int. 159 688 Google Scholar
[12] Podlubny I 1999 Fractional Differential Equations (California: Academic Press) pp270−217
[13] Yang J, Zhu H 2018 Geophys. J. Int. 215 1064 Google Scholar
[14] Chen X W, Zhang R C, Mei F X 2000 Acta Mech. Sin. 16 282 Google Scholar
[15] Dorodnitsyn V, Kozlov R 2010 J. Eng. Math. 66 253 Google Scholar
[16] 方刚, 张斌 2013 物理学报 62 154502 Google Scholar
Fang G, Zhang B 2013 Acta Phys. Sin. 62 154502 Google Scholar
[17] Li H X, Tao C H, Liu C, Huang G N, Yao Z A 2020 Chin. Phys. B 29 064301 Google Scholar
[18] 周聪, 王庆良 2015 物理学报 64 239101 Google Scholar
Zhou C, Wang Q 2015 Acta Phys. Sin. 64 239101 Google Scholar
[19] Zhang Z J, Wang G J, Harris J M 1999 Phys. Earth Planet. Inter. 114 25 Google Scholar
[20] 董良国, 马在田, 曹景忠 2000 地球物理学报 43 856 Google Scholar
Dong L G, Ma Z T, Cao J Z 2000 Chin. J. Geophys 43 856 Google Scholar
[21] 孟路稳, 程广利, 张明敏, 尚建华 2017 海军工程大学学报 29 57
Meng L W, Cheng G L, Zhang M M, Shang J H 2017 J. Naval Univ. Eng. 29 57
[22] 杜启振, 刘莲莲, 孙晶波 2007 物理学报 56 6143 Google Scholar
Du Q, Liu L, Sun J 2007 Acta Phys. Sin. 56 6143 Google Scholar
[23] 唐春安 1997 岩石力学与工程学报 4 75
Tang C A 1997 Chin. J. Rock Mech. Eng. 4 75
[24] Carcione J M 2014 Wave Fields in Real Media (Amsterdam: Elsevier Science) p75
[25] Chen W, Holm S 2004 J. Acoust. Soc. Am. 115 1424 Google Scholar
[26] Carcione J M 2010 Geophysics 75 A53 Google Scholar
目录
- 第70卷,第14期 - 2021年07月20日
计量
- 文章访问数: 4658
- PDF下载量: 139
- 被引次数: 0