<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE article PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Publishing DTD v1.3 20210610//EN" "JATS-journalpublishing1-3.dtd">
<article article-type="research-article" dtd-version="1.3" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xml:lang="ru"><front><journal-meta><journal-id journal-id-type="publisher-id">cheb</journal-id><journal-title-group><journal-title xml:lang="ru">Чебышевский сборник</journal-title><trans-title-group xml:lang="en"><trans-title>Chebyshevskii Sbornik</trans-title></trans-title-group></journal-title-group><issn pub-type="ppub">2226-8383</issn><publisher><publisher-name>Tula State Lev Tolstoy  Pedagogical University</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.22405/2226-8383-2025-26-1-164-180</article-id><article-id custom-type="elpub" pub-id-type="custom">cheb-1942</article-id><article-categories><subj-group subj-group-type="heading"><subject>Research Article</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="ru"><subject>История математики и приложений</subject></subj-group><subj-group subj-group-type="section-heading" xml:lang="en"><subject>Сomputer science</subject></subj-group></article-categories><title-group><article-title>Рассеяние плоской звуковой волны жидким телом сложной формы</article-title><trans-title-group xml:lang="en"><trans-title>Scattering of a plane sound wave by a liquid body of complex shape</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Горбачев</surname><given-names>Дмитрий Викторович</given-names></name><name name-style="western" xml:lang="en"><surname>Gorbachev</surname><given-names>Dmitry Viktorovich</given-names></name></name-alternatives><bio xml:lang="ru"><p>доктор физико-математических наук</p></bio><bio xml:lang="en"><p>doctor of physical and mathematical sciences</p></bio><email xlink:type="simple">dvgmail@mail.ru</email><xref ref-type="aff" rid="aff-1"/></contrib><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Лепетков</surname><given-names>Даниил Русланович</given-names></name><name name-style="western" xml:lang="en"><surname>Lepetkov</surname><given-names>Daniil Ruslanovich</given-names></name></name-alternatives><bio xml:lang="ru"><p>аспирант</p></bio><bio xml:lang="en"><p>postgraduate student</p></bio><email xlink:type="simple">Lepetckov@ya.ru</email><xref ref-type="aff" rid="aff-2"/></contrib><contrib contrib-type="author" corresp="yes"><name-alternatives><name name-style="eastern" xml:lang="ru"><surname>Скобельцын</surname><given-names>Сергей Алексеевич</given-names></name><name name-style="western" xml:lang="en"><surname>Skobel’tsyn</surname><given-names>Sergey Alekseevich</given-names></name></name-alternatives><bio xml:lang="ru"><p>доктор физико-математических наук</p></bio><bio xml:lang="en"><p>doctor of physical and mathematical sciences</p></bio><email xlink:type="simple">skbl@rambler.ru</email><xref ref-type="aff" rid="aff-2"/></contrib></contrib-group><aff-alternatives id="aff-1"><aff xml:lang="ru"><institution>Тульский государственный педагогический университет им. Л. Н. Толстого</institution><country>Россия</country></aff><aff xml:lang="en"><institution>Tula State Lev Tolstoy Pedagogical University</institution><country>Russian Federation</country></aff></aff-alternatives><aff-alternatives id="aff-2"><aff xml:lang="ru"><institution>Тульский государственный университет; Тульский государственный педагогический университет им. Л. Н. Толстого</institution><country>Россия</country></aff><aff xml:lang="en"><institution>Tula State University; Tula State Lev Tolstoy Pedagogical University</institution><country>Russian Federation</country></aff></aff-alternatives><pub-date pub-type="collection"><year>2025</year></pub-date><pub-date pub-type="epub"><day>22</day><month>06</month><year>2025</year></pub-date><volume>26</volume><issue>1</issue><fpage>164</fpage><lpage>180</lpage><permissions><copyright-statement>Copyright &amp;#x00A9; Горбачев Д.В., Лепетков Д.Р., Скобельцын С.А., 2025</copyright-statement><copyright-year>2025</copyright-year><copyright-holder xml:lang="ru">Горбачев Д.В., Лепетков Д.Р., Скобельцын С.А.</copyright-holder><copyright-holder xml:lang="en">Gorbachev D.V., Lepetkov D.R., Skobel’tsyn S.A.</copyright-holder><license xml:lang="ru" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>Данная работа распространяется под лицензией Creative Commons Attribution 4.0.</license-p></license><license xml:lang="en" license-type="creative-commons-attribution" xlink:href="https://creativecommons.org/licenses/by/4.0/" xlink:type="simple"><license-p>This work is licensed under a Creative Commons Attribution 4.0 License.</license-p></license></permissions><self-uri xlink:href="https://www.chebsbornik.ru/jour/article/view/1942">https://www.chebsbornik.ru/jour/article/view/1942</self-uri><abstract><p>Рассматривается задача рассеяния плоской гармонической звуковой волны на препятствии в виде жидкого тела с неканонической формой и кусочно-гладкой поверхностью, которая аппроксимируется полигональной сеткой. Модель процесса строится на базе уравнений гидродинамики идеальной жидкости. Для решения задачи сравниваются два численно-аналитических подхода, основанных на методе конечных элементов (МКЭ) и методе граничных элементов (МГЭ). В первом подходе препятствие заключается в сферу, область внутри которой с учетом поверхности препятствия разбивается на пространственные (3D) конечные элементы. В этой области задача решается МКЭ, что дает значения потенциала на сфере, которые используются для нахождения коэффициентов сферическогоразложения потенциала рассеянной волны. Во втором подходе при помощи пространственной функции Грина для уравнения Гельмгольца задача сводится к системе интегральных уравнений по поверхности препятствия. Также применяется метод Бертона и Миллера для исключения неединственности решения и регуляризация сингулярных интегралов на основе тождеств для статической функции Грина. В МГЭ достаточно использовать раз-биение поверхности на граничные (2D) элементы. Приводятся основные соотношения для применения численных методов и результаты решения задачи рассеяния звука на примережидкого тела, имеющего форму объединения двух шаров одинакового радиуса. Установлено, что для достижения приемлемой точности расчета рассеянного поля метод МГЭтребует существенно меньших вычислительных затрат по сравнению с МКЭ.</p></abstract><trans-abstract xml:lang="en"><p>The problem of scattering of a plane harmonic sound wave by an obstacle in the form of a liquid body with a non-canonical shape and a piecewise-smooth surface, approximated by a polygonal mesh, is considered. The process model is based on the equations of hydrodynamics for an ideal fluid. Two numerical-analytical approaches to solving the problem are compared: the finite element method (FEM) and the boundary element method (BEM). In the first approach,the obstacle is enclosed within a sphere, and the domain inside, taking into account the surface of the obstacle, is divided into spatial (3D) finite elements. In this domain, the problem is solved using FEM, which provides the potential values on the sphere. These values are then used to determine the coefficients of the spherical expansion of the scattered wave potential. In the second approach, using the spatial Green’s function for the Helmholtz equation, the problem isreduced to a system of integral equations over the surface of the obstacle. The Burton-Miller method is also applied to eliminate the non-uniqueness of the solution, and singular integrals are regularized using identities for the static Green’s function. In the BEM, it is sufficient to divide the surface into boundary (2D) elements. The main equations for applying the numerical methods and the results of solving the sound scattering problem for a liquid body in the form of two spheres of equal radius are presented. It is established that to achieve acceptable accuracy in calculating the scattered field, the BEM requires significantly fewer computational resources compared to the FEM.</p></trans-abstract><kwd-group xml:lang="ru"><kwd>рассеяние звука</kwd><kwd>жидкое тело</kwd><kwd>акустический потенциал</kwd><kwd>метод конечных элементов (МКЭ)</kwd><kwd>метод граничных элементов (МГЭ)</kwd><kwd>функция Грина.</kwd></kwd-group><kwd-group xml:lang="en"><kwd>sound scattering</kwd><kwd>liquid body</kwd><kwd>acoustic potential</kwd><kwd>finite element method (FEM)</kwd><kwd>boundary element method (BEM)</kwd><kwd>Green’s function.</kwd></kwd-group><funding-group><funding-statement xml:lang="ru">Работа выполнена в рамках государственного задания Министерства просвещения РФ соглашение № 073-00033-24-01 от 09.02.2024 тема научного исследования «Теоретико-числовые методы в приближенном анализе и их приложения в механике и физике».</funding-statement></funding-group></article-meta></front><back><ref-list><title>References</title><ref id="cit1"><label>1</label><citation-alternatives><mixed-citation xml:lang="ru">Frisk G.V., DeSanto J.A. Scattering by spherically symmetric inhomogeneities // J. Acoust. Soc. Amer. 1970. Vol. 47, № 1B. P. 172–180.</mixed-citation><mixed-citation xml:lang="en">Frisk, G.V. &amp; DeSanto, J.A. 1970, “Scattering by spherically symmetric inhomogeneities”, J. Acoust. Soc. Amer., vol. 47, no. 1B, pp. 172–180.</mixed-citation></citation-alternatives></ref><ref id="cit2"><label>2</label><citation-alternatives><mixed-citation xml:lang="ru">¨Uberall H., George J., Farhan A.R., Mezzorani G., Nagl A., Sage K.A., Murphy J.D. Dynamics of acoustic resonance scattering from spherical targets: Application to gas bubbles in fluids // J. Acoust. Soc. Amer. 1979. Vol. 66. P. 1161–1172.</mixed-citation><mixed-citation xml:lang="en">¨Uberall, H., George, J., Farhan, A.R., Mezzorani, G., Nagl, A., Sage, K.A. &amp; Murphy, J.D. 1979, “Dynamics of acoustic resonance scattering from spherical targets: Application to gas bubbles in fluids”, J. Acoust. Soc. Amer., vol. 66, pp. 1161–1172.</mixed-citation></citation-alternatives></ref><ref id="cit3"><label>3</label><citation-alternatives><mixed-citation xml:lang="ru">Буров В.А., Румянцева О.Д. Единственность и устойчивость решения обратной задачи акустического рассеяния // Акуст. журн. 2003. Том. 49. № 5. С. 590–603.</mixed-citation><mixed-citation xml:lang="en">Burov, V.A. &amp; Rumyantseva, O.D. 2003, “Uniqueness and stability of the solution to an inverse acoustic scattering problem”, Acoust. Phys., vol. 49, no. 5, pp. 496–507.</mixed-citation></citation-alternatives></ref><ref id="cit4"><label>4</label><citation-alternatives><mixed-citation xml:lang="ru">Martin P.A. Acoustic scattering by inhomogeneous obstacles // SIAM J. Appl. Math. 2003. Vol. 64, № 1. P. 297–308.</mixed-citation><mixed-citation xml:lang="en">Martin, P.A. 2003, “Acoustic scattering by inhomogeneous obstacles”, SIAM J. Appl. Math., vol. 64, no. 1, pp. 297–308.</mixed-citation></citation-alternatives></ref><ref id="cit5"><label>5</label><citation-alternatives><mixed-citation xml:lang="ru">Буров В.А., Попов А.Ю., Сергеев С.Н., Шуруп А.С. Акустическая томография океана при использовании нестандартного представления рефракционных неоднородностей // Акуст. журн. 2005. Том. 51. № 5. С. 602–613.</mixed-citation><mixed-citation xml:lang="en">Burov, V.A., Popov, A.Y., Sergeev, S.N. &amp; Shurup, A.S. 2005, “Ocean acoustic tomography with a nonstandard representation of refractive inhomogeneities”, Acoust. Phys., vol. 51, no. 5, pp. 513–523.</mixed-citation></citation-alternatives></ref><ref id="cit6"><label>6</label><citation-alternatives><mixed-citation xml:lang="ru">Алексеенко Н.В., Буров В.А., Румянцева О.Д. Решение трехмерной обратной задачи акустического рассеяния на основе алгоритма Новикова-Хенкина // Акуст. журн. 2005. Том. 51. № 4. С. 437–446.</mixed-citation><mixed-citation xml:lang="en">Alekseenko, N.V., Burov, V.A. &amp; Rumyantseva, O.D. 2005, “Solution of the three-dimensional inverse acoustic scattering problem on the basis of the Novikov–Henkin algorithm”, Acoust. Phys., vol. 51, no. 4, pp. 367–375.</mixed-citation></citation-alternatives></ref><ref id="cit7"><label>7</label><citation-alternatives><mixed-citation xml:lang="ru">Hasheminejad S.M., Sanaei R. Ultrasonic scattering by a fluid cylinder of elliptic cross section, including viscous effects // IEEE Trans. Ultrason. Ferroelectr. Freq. Control. 2008. Vol. 55, № 2. P. 391–404.</mixed-citation><mixed-citation xml:lang="en">Hasheminejad, S.M. &amp; Sanaei, R. 2008, “Ultrasonic scattering by a fluid cylinder of elliptic cross section, including viscous effects”, IEEE Trans. Ultrason. Ferroelectr. Freq. Control., vol. 55, no. 2, pp. 391–404.</mixed-citation></citation-alternatives></ref><ref id="cit8"><label>8</label><citation-alternatives><mixed-citation xml:lang="ru">Буров В.А., Шмелев А.А. Численное и физическое моделирование процесса томографии на основе акустических нелинейных эффектов третьего порядка // Акуст. журн. 2009. Том. 55. № 4–5. С. 466–480.</mixed-citation><mixed-citation xml:lang="en">Burov, V.A. &amp; Shmelev, A.A. 2009, “Numerical and physical modeling of the tomography process based on third-order nonlinear acoustic effects”, Acoust. Phys., vol. 55, no. 4, 482–495.</mixed-citation></citation-alternatives></ref><ref id="cit9"><label>9</label><citation-alternatives><mixed-citation xml:lang="ru">Duck F.A., Baker A.C., Starritt H.C. (ed.) Ultrasound in medicine. Boca Raton: CRC Press, 2020.</mixed-citation><mixed-citation xml:lang="en">Duck, F.A., Baker, A.C. &amp; Starritt, H.C. (eds). 2020, “Ultrasound in medicine”, CRC Press, Boca Raton.</mixed-citation></citation-alternatives></ref><ref id="cit10"><label>10</label><citation-alternatives><mixed-citation xml:lang="ru">Li P., Zhai J., Zhao Y. Stability for the acoustic inverse source problem in inhomogeneous media // SIAM J. Appl. Math. 2020. Vol. 80, № 6. P. 2547–2559.</mixed-citation><mixed-citation xml:lang="en">Li, P., Zhai, J. &amp; Zhao, Y. 2020, “Stability for the acoustic inverse source problem in inhomogeneous media”, SIAM J. Appl. Math., vol. 80, no. 6, pp. 2547–2559.</mixed-citation></citation-alternatives></ref><ref id="cit11"><label>11</label><citation-alternatives><mixed-citation xml:lang="ru">Skudrzyk E. The foundations of acoustics basic mathematics and basic acoustics. New York, Wien: Springer-Verlag, 1971.</mixed-citation><mixed-citation xml:lang="en">Skudrzyk, E. 1971, “The foundations of acoustics basic mathematics and basic acoustics”, Springer-Verlag, New York, Wien.</mixed-citation></citation-alternatives></ref><ref id="cit12"><label>12</label><citation-alternatives><mixed-citation xml:lang="ru">Исакович М.А. Общая акустика. М.: Наука, 1973.</mixed-citation><mixed-citation xml:lang="en">Isakovich, M.A. 1973, “General acoustics”, Nauka, Moscow. (In Russ.)</mixed-citation></citation-alternatives></ref><ref id="cit13"><label>13</label><citation-alternatives><mixed-citation xml:lang="ru">Anderson V.C. Sound scattering from a fluid sphere // J. Acoust. Soc. Amer. 1950. Vol. 22, № 4. P. 426–431.</mixed-citation><mixed-citation xml:lang="en">Anderson, V.C. 1950, “Sound scattering from a fluid sphere”, J. Acoust. Soc. Amer., vol. 22, no. 4, pp. 426–431.</mixed-citation></citation-alternatives></ref><ref id="cit14"><label>14</label><citation-alternatives><mixed-citation xml:lang="ru">Иванов В.И., Скобельцын С.А. Моделирование решений задач акустики с использованием МКЭ // Известия ТулГУ. Естественные науки. 2008. Вып. 2. С. 132–145.</mixed-citation><mixed-citation xml:lang="en">Ivanov, V.I. &amp; Skobel’tsyn, S.A. 2008, “Modeling solutions to acoustics using FEM”, Izv. Tul. Gos. Univ., Ser. Estestv. Nauki, no. 2, pp. 132–145. (In Russ.)</mixed-citation></citation-alternatives></ref><ref id="cit15"><label>15</label><citation-alternatives><mixed-citation xml:lang="ru">Скобельцын С.А. Некоторые обратные задачи дифракции звуковых волн на неоднородных анизотропных упругих телах // Дисс. . . . докт. физ.-мат. наук. Тула, ТулГУ, 2020.</mixed-citation><mixed-citation xml:lang="en">Skobeltsyn, S.A. 2020, “Some inverse problems of diffraction of sound waves on inhomogeneous anisotropic elastic bodies”, Diss. . . . doc. physics and mathematics Sci., Tula State University, Tula. (In Russ.).</mixed-citation></citation-alternatives></ref><ref id="cit16"><label>16</label><citation-alternatives><mixed-citation xml:lang="ru">Ihlenburg F. Finite element analysis of acoustic scattering. New York: Springer, 2013.</mixed-citation><mixed-citation xml:lang="en">Ihlenburg, F. 2013, “Finite element analysis of acoustic scattering”, Springer, New York.</mixed-citation></citation-alternatives></ref><ref id="cit17"><label>17</label><citation-alternatives><mixed-citation xml:lang="ru">Burton A.J., Miller G.F. The application of integral equation methods to the numerical solution of some exterior boundary-value problems // Proc. R. Soc. Lond. A. Math. Phys. Sci. 1971. Vol. 323, № 1553. P. 201–210.</mixed-citation><mixed-citation xml:lang="en">Burton, A.J. &amp; Miller, G.F. 1971, “The application of integral equation methods to the numerical solution of some exterior boundary-value problems”, Proc. R. Soc. Lond. A. Math. Phys. Sci., vol. 323, no. 1553, pp. 201–210.</mixed-citation></citation-alternatives></ref><ref id="cit18"><label>18</label><citation-alternatives><mixed-citation xml:lang="ru">Бреббия К. Теллес Ж., Вроубел Л. Методы граничных элементов / Пер. с англ. М.: Мир, 1987.</mixed-citation><mixed-citation xml:lang="en">Brebbia, C.A., Telles, J.C.F. &amp; Wrobel, L.C. 1984, “Boundary element techniques, theory and applications in engineering”, Springer, Berlin.</mixed-citation></citation-alternatives></ref><ref id="cit19"><label>19</label><citation-alternatives><mixed-citation xml:lang="ru">Chen K., Cheng J., Harris P.J. A new study of the Burton and Miller method for the solution of a 3D Helmholtz problem // IMA J. Appl. Math. 2009. Vol. 74, № 2. P. 163–177.</mixed-citation><mixed-citation xml:lang="en">Chen, K., Cheng, J. &amp; Harris, P.J. 2009, “A new study of the Burton and Miller method for the solution of a 3D Helmholtz problem”, IMA J. Appl. Math., vol. 74, no. 2, pp. 163–177.</mixed-citation></citation-alternatives></ref><ref id="cit20"><label>20</label><citation-alternatives><mixed-citation xml:lang="ru">Chen G., Zhou J. Boundary element methods with applications to nonlinear problems / 2nd ed. Springer: Dordrecht, 2010.</mixed-citation><mixed-citation xml:lang="en">Chen, G. &amp; Zhou, J. 2010, “Boundary element methods with applications to nonlinear problems”, 2nd ed., Springer, Dordrecht.</mixed-citation></citation-alternatives></ref><ref id="cit21"><label>21</label><citation-alternatives><mixed-citation xml:lang="ru">Simpson R.N., Scott M.A., Taus M., Thomas D.C., Lian H. Acoustic isogeometric boundary element analysis // Comput. Methods Appl. Mech. Eng. 2014. Vol. 269. P. 265–290.</mixed-citation><mixed-citation xml:lang="en">Simpson, R.N., Scott , M.A., Taus M., Thomas D.C. &amp; Lian H. 2014, “Acoustic isogeometric boundary element analysis”, Comput. Methods Appl. Mech. Eng., vol. 269, pp. 265–290.</mixed-citation></citation-alternatives></ref><ref id="cit22"><label>22</label><citation-alternatives><mixed-citation xml:lang="ru">Amini S. On the choice of the coupling parameter in boundary integral formulations of the exterior acoustic problem // Appl. Anal. 1990. Vol. 35. P. 75–92.</mixed-citation><mixed-citation xml:lang="en">Amini, S. 1990, “On the choice of the coupling parameter in boundary integral formulations of the exterior acoustic problem”, Appl. Anal., vol. 35, pp. 75–92.</mixed-citation></citation-alternatives></ref><ref id="cit23"><label>23</label><citation-alternatives><mixed-citation xml:lang="ru">Liu Y.J., Rudolphi T.J. Some identities for fundamental-solutions and their applications to weakly-singular boundary element formulations // Eng. Anal. Bound. Elem. 1991. Vol. 8, № 6. P. 301–311.</mixed-citation><mixed-citation xml:lang="en">Liu, Y.J. &amp; Rudolphi, T.J. 1991, “Some identities for fundamental-solutions and their applications to weakly-singular boundary element formulations”, Eng. Anal. Bound. Elem., vol. 8, no. 6, pp. 301–311.</mixed-citation></citation-alternatives></ref><ref id="cit24"><label>24</label><citation-alternatives><mixed-citation xml:lang="ru">Wilton D.R., Rao S.M., Glisson A.W., Schaubert D.H., Al-Bundak O.M., Butler C.M. Potential integrals for uniform and linear source distnbutions on polygonal and polyhedral domains // IEEE Trans. Antennas Propagat. 1984. Vol. 32, no. 3. P. 276–281.</mixed-citation><mixed-citation xml:lang="en">Wilton, D.R., Rao, S.M., Glisson, A.W., Schaubert, D.H., Al-Bundak, O.M. &amp; Butler, C.M. 1984, “Potential integrals for uniform and linear source distnbutions on polygonal and polyhedral domains”, IEEE Trans. Antennas Propagat., vol. 32, no. 3, pp. 276–281.</mixed-citation></citation-alternatives></ref><ref id="cit25"><label>25</label><citation-alternatives><mixed-citation xml:lang="ru">Lin T.C. A proof for the Burton and Miller integral equation approach for the Helmholtz equation // J. Math. Anal. Appl. 1984. Vol. 103, № 2. P. 565–574.</mixed-citation><mixed-citation xml:lang="en">Lin, T.C. 1984, “A proof for the Burton and Miller integral equation approach for the Helmholtz equation”, J. Math. Anal. Appl., vol. 103, no. 2, pp. 565–574.</mixed-citation></citation-alternatives></ref><ref id="cit26"><label>26</label><citation-alternatives><mixed-citation xml:lang="ru">Jackson J.D. Classical electrodynamics / 3rd ed. N.Y.: Wiley City, 1999.</mixed-citation><mixed-citation xml:lang="en">Jackson, J.D. 1999, “Classical electrodynamics”, 3rd ed., Wiley City, New York.</mixed-citation></citation-alternatives></ref><ref id="cit27"><label>27</label><citation-alternatives><mixed-citation xml:lang="ru">Meyer M., Desbrun M., Schr¨oder P., Barr A.H. Discrete differential-geometry operators for triangulated 2-manifolds // In: H.-C. Hege, K. Polthier (eds) Visualization and Mathematics III. Mathematics and Visualization. Berlin–Heidelberg: Springer, 2003.</mixed-citation><mixed-citation xml:lang="en">Meyer, M., Desbrun, M., Schr¨oder, P. &amp; Barr, A.H. 2003, “Discrete differential-geometry operators for triangulated 2-manifolds”, In: H.-C. Hege, K. Polthier (eds) Visualization and Mathematics III. Mathematics and Visualization, Springer, Berlin–Heidelberg.</mixed-citation></citation-alternatives></ref><ref id="cit28"><label>28</label><citation-alternatives><mixed-citation xml:lang="ru">Халилов Э.Г. Обоснование метода коллокации для интегрального уравнения смешанной краевой задачи для уравнения Гельмгольца // ЖВМ и МФ. 2016. Том. 56. № 7. С. 1340–1348.</mixed-citation><mixed-citation xml:lang="en">Khalilov, E.H. 2016, “Justification of the collocation method for the integral equation for a mixed boundary value problem for the Helmholtz equation”, Comput. Math. Math. Phys., vol. 56, no. 7, pp. 1310–1318.</mixed-citation></citation-alternatives></ref><ref id="cit29"><label>29</label><citation-alternatives><mixed-citation xml:lang="ru">Колтон Д., Кресс Р. Методы интегральных уравнений в теории рассеяния. М.: Мир, 1987.</mixed-citation><mixed-citation xml:lang="en">Colton, D. &amp; Kress, R. 2013, “Integral equation methods in scattering theory”, SIAM, Philadelphia.</mixed-citation></citation-alternatives></ref></ref-list><fn-group><fn fn-type="conflict"><p>The authors declare that there are no conflicts of interest present.</p></fn></fn-group></back></article>
