The electrostatics of two cylinders charged to the symmetrical or anti-symmetrical potential is investigated by using the null-field boundary integral equation (BIE) in conjunction with the degenerate kernel of the bipolar coordinates. The undetermined coefficient is obtained according to the Fredholm alternative theorem. The uniqueness of solution, infinite solution, and no solution are examined therein. A single cylinder (circle or ellipse) is also provided for comparison. The link to the general solution space is also done. The condition at infinity is also correspondingly examined. The flux equilibrium along circular boundaries and the infinite boundary is also checked as well as the contribution of the boundary integral (single and double layer potential) at infinity in the BIE is addressed. Ordinary and degenerate scales in the BIE are both discussed. Furthermore, the solution space represented by the BIE is explained after comparing it with the general solution. The present finding is compared to those of Darevski [
Citation: Jeng-Tzong Chen, Shing-Kai Kao, Yen-Ting Chou, Wei-Chen Tai. On the solution arising in two-cylinders electrostatics[J]. Mathematical Biosciences and Engineering, 2023, 20(6): 10007-10026. doi: 10.3934/mbe.2023439
The electrostatics of two cylinders charged to the symmetrical or anti-symmetrical potential is investigated by using the null-field boundary integral equation (BIE) in conjunction with the degenerate kernel of the bipolar coordinates. The undetermined coefficient is obtained according to the Fredholm alternative theorem. The uniqueness of solution, infinite solution, and no solution are examined therein. A single cylinder (circle or ellipse) is also provided for comparison. The link to the general solution space is also done. The condition at infinity is also correspondingly examined. The flux equilibrium along circular boundaries and the infinite boundary is also checked as well as the contribution of the boundary integral (single and double layer potential) at infinity in the BIE is addressed. Ordinary and degenerate scales in the BIE are both discussed. Furthermore, the solution space represented by the BIE is explained after comparing it with the general solution. The present finding is compared to those of Darevski [
[1] | S. W. Chyuan, Y. S. Liao, J. T. Chen, An efficient method for solving electrostatic problems, Comput. Sci. Eng., 5 (2003), 52–58. https://doi.org/10.1109/MCISE.2003.1196307 doi: 10.1109/MCISE.2003.1196307 |
[2] | A. I. Darevski, The electrostatic field of a split phase (in Russian), Elektrichestvo, 78 (1958), 16–19. |
[3] | G. Quilico, Campo elettrico di un conduttore bifilare, L'Elettrotecnica, 41 (1954), 530–538. |
[4] | J. Lekner, Identities arising from two-cylinder electrostatics, Int. J. Math. Anal., 7 (2013), 1411–1417. https://doi.org/10.12988/ijma.2013.3115 doi: 10.12988/ijma.2013.3115 |
[5] | F. J. W. Whipple, Equal parallel cylindrical conductors in electrical problems, Proc. R. Soc. A, 96 (1920), 465–474. https://doi.org/10.1098/rspa.1920.0010 doi: 10.1098/rspa.1920.0010 |
[6] | H. Poritsky, The field due to two equally charged parallel conducting cylinders, J. Math. Phys., 11 (1932), 213–217. https://doi.org/10.1002/sapm1932111213 doi: 10.1002/sapm1932111213 |
[7] | J. Lekner, Four solutions of a two-cylinder electrostatic problem, and identities resulting from heir equivalence, Q. J. Mech. Appl. Math. 73 (2013), 251–260. https://doi.org/10.1093/qjmam/hbaa010 doi: 10.1093/qjmam/hbaa010 |
[8] | N. N. Lebedev, I. P. Skalskaya, Y. S. Uflyand, Worked problems in applied mathematics, Dover Publications, New York, 1979. |
[9] | J. T. Chen, W. C. Shen, Degenerate scale for multiply connected Laplace problems, Mech. Res. Commu., 34 (2007), 69–77. https://doi.org/10.1016/j.mechrescom.2006.06.009 doi: 10.1016/j.mechrescom.2006.06.009 |
[10] | J. T. Chen, S. K. Kao, J. W. Lee, Analytical derivation and numerical experiment of degenerate scale by using the degenerate kernel of the bipolar coordinates, Eng. Anal. Boundary Elem., 85 (2017), 70–86. https://doi.org/10.1016/j.enganabound.2017.08.006 doi: 10.1016/j.enganabound.2017.08.006 |
[11] | S. W. Chyuan, Y. S. Liao, J. T. Chen, Efficient techniques for BEM rank-deficiency electrostatic problems, J. Electrostat., 66 (2008), 8–15. https://doi.org/10.1016/j.elstat.2007.06.006 doi: 10.1016/j.elstat.2007.06.006 |
[12] | S. R. Kuo, J. T. Chen, J. W. Lee, Y. W. Chen, Analytical derivation and numerical experiments of degenerate scale for regular N-gon domains in two-dimensional Laplace problems, Appl. Math. Comput., 219 (2013), 5668–5683. https://doi.org/10.1016/j.amc.2012.11.008 doi: 10.1016/j.amc.2012.11.008 |
[13] | S. R. Kuo, S. K. Kao, Y. L. Huang, J. T. Chen, Revisit of the degenerate scale for an infinite plane problem containing two circular holes using conformal mapping, Appl. Math. Lett., 92 (2019), 99–107. https://doi.org/10.1016/j.aml.2018.11.023 doi: 10.1016/j.aml.2018.11.023 |
[14] | J. T. Chen, S. R. Kuo, Y. L. Huang, S. K. Kao, Linkage of logarithmic capacity in potential theory and degenerate scale in the BEM for the two tangent discs, Appl. Math. Lett., 102 (2020), 106135. https://doi.org/10.1016/j.aml.2019.106135 doi: 10.1016/j.aml.2019.106135 |
[15] | J. T. Chen, S. R. Kuo, Y. L. Huang, S. Kao, Revisit of logarithmic capacity of line segments and double-degeneracy of BEM/BIEM, Eng. Anal. Boundary Elem., 120 (2020), 238–245. https://doi.org/10.1016/j.enganabound.2020.08.003 doi: 10.1016/j.enganabound.2020.08.003 |
[16] | J. T. Chen, J. H. Kao, S. K. Kao, C. H. Shiao, W. C. Tai, On the role of singular and hypersingular BIEs for the BVPs containing a degenerate boundary, Eng. Anal. Boundary Elem., 133 (2021), 214–235. https://doi.org/10.1016/j.enganabound.2021.07.018 doi: 10.1016/j.enganabound.2021.07.018 |
[17] | J. T. Chen, J. H. Kao, S. K. Kao, W. C. Tai, An indirect BIE free of degenerate scales, Commun. Pure Appl. Anal., 21 (2022), 1969–1985. https://doi.org/10.3934/cpaa.2021114 doi: 10.3934/cpaa.2021114 |
[18] | J. T. Chen, J. H. Kao, S. K. Kao, Y. T. Lee, S. R. Kuo, Study on the double-degeneracy mechanism of BEM/BIEM for a plane elasticity problem, Eng. Anal. Boundary Elem., 136 (2022), 290–302. https://doi.org/10.1016/j.enganabound.2021.12.002 doi: 10.1016/j.enganabound.2021.12.002 |
[19] | G. Strang, Introduction to Linear Algebra, Wellesley Cambridge Press, Wellesley, 2016. |
[20] | J. G. Fikioris, J. L. Tsalamengas, Exact solutions for rectangularly shielded lines by the Carleman-Vekua method, IEEE Trans. Microwave Theory Tech. 36 (1988), 659–675. https://doi.org/10.1109/22.3570 doi: 10.1109/22.3570 |
[21] | R. P. Kanwal, Singular integral equations, in Linear Integral Equations, Theory and Technique, Springer, New York, (1971), 167–193. https://doi.org/10.1016/B978-0-12-396550-9.50012-1 |
[22] | J. T. Chen, H. D. Han, S. R. Kuo, S. K. Kao, Regularized methods for ill-conditioned system of the integral equations of the first kind with the logarithmic kernel, Inverse Probl. Sci. Eng., 22 (2014), 1176–1195. https://doi.org/10.1080/17415977.2013.856900 doi: 10.1080/17415977.2013.856900 |
[23] | R. S. Rumely, Capacity Theory on Algebraic Curves, Springer, Berlin, 1989. https://doi.org/10.1007/BFb0084525 |
[24] | J. T. Chen, J. W. Lee, S. K. Kao, W. C. Tai, Interaction between a screw dislocation and an elliptical hole or rigid inclusion by using the angular basis function, J. Appl. Math. Mech., 102 (2022), 1–9. |