A non-axisymmetric diffraction problem of cylindrical sound waves on an elastic cylinder with an inhomogeneous coating located near the boundary of an elastic half-space
https://doi.org/10.22405/2226-8383-2024-25-2-269-285
Abstract
The article considers the problem of diffraction of a cylindrical sound wave on a homogeneous
isotropic elastic cylinder with a radially inhomogeneous elastic coating located near the
boundary of half-spaces in the case when the linear source is in a plane parallel to the surface of the half-space and is not parallel to the axis of the cylinder. It is assumed that the cylinder is located in a half-space filled with an ideal homogeneous liquid bordering on a homogeneous elastic half-space.
To represent the scattered field in an ideal liquid, a representation in the form of the Helmholtz-Kirchhoff integral is used. The oscillations of an inhomogeneous isotropic elastic body are described by the equations of the linear theory of elasticity. To find the displacement field in an inhomogeneous coating, a boundary value problem for a system of second-order
ordinary differential equations is constructed.
Based on the solution of the direct problem, the inverse problem of determining the laws of coating heterogeneity that provide the least sound reflection in a given frequency range is considered. A functional is constructed expressing the average intensity of sound scattering in a given frequency range. The constructed functional is written in the form of a double integral, which cannot be evaluated analytically. The resulting integral is calculated numerically using a quadrature formula based on a parallelepipedal Korobov grid.
Numerical calculations of the angular characteristics of the scattered field are presented.
A significant effect of continuously inhomogeneous coatings on the diffraction pattern of the scattered field has been revealed.
About the Authors
Nikolai Nikolaevich Dobrovol’skiiRussian Federation
candidate of physical and mathematical sciences
Dmitrii Yurevich Efimov
Russian Federation
postgraduate student
Lev Alexeevich Tolokonnikov
Russian Federation
doctor of physical and mathematical sciences, professor
References
1. Ivanov, V.P. 2006. “Analysis of the field diffracted by a cylinder with a perforated coating”,
2. Acoustical Physics vol. 52, no 6, pp. 683-690.
3. Bobrovnitskii, Yu. I. 2008. “A nonscattering coating for a cylinder”, Acoustical Physics, vol. 54, no 6, pp. 758-768.
4. Kosarev, O. I. 2012. “Diffraction of sound by an elastic cylindrical shell with a coating”, Probl. Mashinostr. Nadezh. Mashin, vol. 46, no 1, pp. 34-37, [in Russian].
5. Larin, N. V. & Tolokonnikov, L. A. 2015. “The scattering of a plane sound wave by an elastic
6. cylinder with a discrete-layered covering”, J. Appl. Math. Mech., vol. 79. no 2, pp. 164-169.
7. Romanov, A. G. & Tolokonnikov, L. A. 2011. “The scattering of acoustic waves by a cylinder
8. with a non-uniform elastic coating”, J. Appl. Math. Mech., vol. 75, no. 5, pp. 595-600.
9. Tolokonnikov, L. A. 2013. “Scattering of an obliquely incident plane sound wave by an elastic cylinder with a non-uniform covering”, Izv. Tul. Gos. Univ., Ser. Estestv. Nauki, no. 2-2,
10. pp. 265-274, [in Russian].
11. Lee F. A. 1963. “Scattering of a cylindrical wave of sound by an elastic cylinder”, Acustica, vol. 13, no. 3. pp. 26-31.
12. Tolokonnikov, L. A. & Efimov, D.Yu. 2021. “ Diffraction of cylindrical sound waves by an
13. elastic cylinder with radially inhomogeneous coating”, Chebyshevskii sbornik, vol. 22, no. 1, pp. 460-472, [in Russian].
14. Korsunskii, S. V. 1988. “The non-axisymmetric diffraction problem of cylindrical sound waves on an absolutely rigid cylinder“, Akust. Zhurnal, vol. 34, no. 3, pp. 481-484, [in Russian].
15. Tolokonnikov, L. A. & Efimov, D.Yu. 2024. “Scattering by an elastic cylinder with an
16. inhomogeneous coating of sound waves emitted by an arbitrarily located linear source”,
17. Mathematical modeling, vol. 36, no. 1, pp. 71-84, [in Russian].
18. Tolokonnikov, L. A. 2018. “Diffraction of a plane sound waves by an elastic cylinder with an
19. non-uniform coating situated near to a flat surface”, Izv. Tul. Gos. Univ., Ser. Tekh. Nauki ,
20. no. 9, pp. 276-289, [in Russian].
21. Tolokonnikov, L. A. & Efimov D.Yu. 2020. “Scattering of a plane sound waves by an elastic
22. cylinder with an non-uniform coating situated near to a flat surface”, Chebyshevskii sbornik,
23. vol. 21, no. 4, pp. 369-381, [in Russian].
24. Shenderov, E. L. 2002. “Diffraction of sound by an elastic cylinder near the surface of an elastic halfspace”, Acoustical Physics, vol. 48, no. 2, pp. 225–234.
25. Tolokonnikov, L. A. & Efimov, D.Yu. 2021. “Diffraction of sound waves at an elastic cylinder
26. with an inhomogeneous coating in the vicinity of the boundary of an elastic half-space”,
27. Mechanics of Solids, vol. 56, no. 8, pp. 1657-1667.
28. Felsen, L. B., Marcuvitz, N. 1973. “Radiation and scattering of waves”, Prentice-Hall, Inc.,
29. Englewood Cliffs, New Jersey.
30. Ivanov, E.A. 1968. “Diffraction of electromagnetic waves by two bodies”, Nauka i tekhnika,
31. Minsk, 584 p., [in Russian].
32. Brekhovskikh, L. M. 1973. “Waves in Layered Media”, Nauka, Moscow, 344 p., [in Russian].
33. Shenderov, E. L. 1972, “Wave problems of underwater acoustics”, Sudostroenie, Leningrad, 352 p. [in Russian].
34. Efimov, D.Yu. 2023, “Diffraction of sound from a point source on an elastic cylinder with an
35. inhomogeneous coating located near the elastic boundary”, Chebyshevskii sbornik, vol. 24, no. 5, pp. 289-306, [in Russian].
36. Nowacki, W. 1973. “Teoria sprezystosci”, PWN, Warszawa.
37. Kurant, R. 1964. “Partial Differential Equations”, Mir, Moscow, 830 p., [in Russian].
38. Zavyialov, Yu. S., Kvasov, B. I. & Miroshnichenko, V. L. 1980. “Spline function methods”, Nauka, Мoscow, 352 p., [in Russian].
39. Tolokonnikov, L. A. & Efimov D.Yu. 2022. “Modeling the inhomogeneous anisotropic coating of an elastic cylinder that provides minimal sound reflection”, Chebyshevskii sbornik, vol. 23, no. 1, pp. 293–311, [in Russian].
40. Kalitkin, N. N. 1978. “Numerical methods”, Fizmatgiz, Moscow, 512 p., [in Russian].
41. Korobov, N. M. 2004. “Teoretiko-chislovye metody v priblizhennom analize [Number-theoretic methods in approximate analysis]”, 2nd ed., MTSNMO, Moscow, Russia.
42. Dobrovol‘skii, N. N., Skobel‘tsyn, S. A., Tolokonnikov, L. A., Larin, N. V. 2021. “About application of number-theoretic grids in problems of acoustics”, Chebyshevskii sbornik, vol. 22, no. 3, pp. 368-382, [in Russian].
Review
For citations:
Dobrovol’skii N.N., Efimov D.Yu., Tolokonnikov L.A. A non-axisymmetric diffraction problem of cylindrical sound waves on an elastic cylinder with an inhomogeneous coating located near the boundary of an elastic half-space. Chebyshevskii Sbornik. 2024;25(2):269-285. (In Russ.) https://doi.org/10.22405/2226-8383-2024-25-2-269-285