余 濤,李今欣
二維低波速Helmholtz方程的異質(zhì)多尺度-內(nèi)部懲罰間斷有限元方法
*余 濤,李今欣
(井岡山大學(xué)數(shù)理學(xué)院,江西,吉安 343009)
將異質(zhì)多尺度方法和內(nèi)部懲罰間斷有限元方法相結(jié)合,構(gòu)造了求解二維低波速Helmholtz方程的異質(zhì)多尺度-內(nèi)部懲罰間斷有限元方法,并在局部周期條件下給出了算法的最佳誤差估計(jì)。
Helmholtz方程;低波速;異質(zhì)多尺度方法;內(nèi)部懲罰間斷有限元方法;先驗(yàn)誤差估計(jì)
考慮具有齊次Dirichlet邊界條件的Helmholtz方程
異質(zhì)多尺度方法[4-5]是求解多尺度問題的一個有效通用框架,其由兩部分組成:選擇合適的宏觀求解器和通過求解局部微觀問題估計(jì)缺失的宏觀系數(shù)。Ciarler和Stohrer采用標(biāo)準(zhǔn)有限元作為宏觀求解器構(gòu)造了求解高震蕩介質(zhì)中Helmholtz方程的異質(zhì)多尺度有限元方法[6]。Abdulle將異質(zhì)多尺度方法和間斷有限元方法相結(jié)合提出了求解純擴(kuò)散問題的算法[7-8]?,F(xiàn)將在異質(zhì)多尺度方法框架下采用內(nèi)部懲罰間斷有限元方法作為宏觀求解器,構(gòu)造求解二維低波速Helmholtz方程的異質(zhì)多尺度-內(nèi)部懲罰間斷有限元方法,并得到最佳的先驗(yàn)誤差估計(jì)。
與
其中
與
和
和
其中
與
在推導(dǎo)模型誤差時,先引入下面的引理。
先驗(yàn)誤差估計(jì)結(jié)果如下:
根據(jù)內(nèi)部懲罰間斷有限元方法的誤差估計(jì)[10-12],可知宏觀誤差
又根據(jù)標(biāo)準(zhǔn)數(shù)值積分誤差分析[13],結(jié)合數(shù)值積分精度(1.8)式易知
由文獻(xiàn)[7-8]中的結(jié)論
可知模型誤差
由(2.2)~(2.5)式,有
[1] Ihlenburg F. Finite element analysis of acoustic scattering[M]. New York:Spring,1998.
[2] Allaire G. Homogenization and two-scale convergence[J]. SIAM Journal on Mathematical Analysis, 1992, 23(6): 1482-1518.
[3] Oleinik O A, Shamaev A S, Yosifian G A. Mathematical problems in elasticity and homogenization[M]. Amsterdam: North-Holland, 1992.
[4] Abdulle A E W, Engquist B, Vanden E. The heterogeneous multiscale method[J]. Acta Numerica, 2012, 21:1-87.
[5] Engquist B E W. The heterogeneous multiscale methods[J]. Communications in Mathematical Sciences, 2003, 1(1):87-132.
[6] Ciarlet P, Stohrer C. Finite - element heterogeneous multiscale method for the Helmholtz equation[J]. C.R. Acad. Sci. Paris, Ser. I, 2014, 352:755-760.
[7] Abdulle A. Multiscale method based on discontinuous galerkin methods for homogenization problems[J]. Comptes Rendus Mathematique, 2008, 346(1):97-102.
[8] Abdulle A. Discontinuous Galerkin ginite element heterogeneous multiscale method for elliptic problems with multiple scales[J]. Mathematics of Computation, 2012, 81(278):687-713.
[9] Fu S, Li G, Chung E T. An edge multiscale interior penalty discontinuous Galerkin method for heterogeneous Helmholtz problems with large varying wavenumber[J]. Journal of Computational Physics, 2021, 441:110387.
[10] Lam C Y, Shu C W. A phase-based interior penalty discontinuous Galerkin method for the Helmholtz equation with spatially varying wavenumber[J]. Computational Methods in Applied Mathematics, 2017, 318:456-473.
[11] Melenk J M, Parsania A, Sauter S. General DG-methods for highly indefinite Helmholtz problems[J]. Journal of Scientific Computing, 2013, 57:536-581.
[12] Du Y, Zhang Z. Supercloseness of linear DG-FEM and its superconvergence based on the polynomial preserving recovery for Helmholtz equation[J]. Journal of Scientific Computing, 2019, 79(3):1713-1736.
[13] Ciarlet P G. The finite element method for elliptic problems[M]. Amsterdam:North-Holland, 1978.
[14] Ciarlet P. T-Coercivity: application to the discretization of Helmholtz-Like problems[J]. Computers & Mathematics with Applications, 2012,64(1):22-34.
[15] 張姊同,曹艷華,朱挺欣.一類高階橢圓型方程特征值的多項(xiàng)式特解法[J].井岡山大學(xué)學(xué)報:自然科學(xué)版,2022, 43 (2):8-14.
[16] Chen Y F, Hou T Y, Wang Y X. Exponentially convergent multiscale methods for 2D high frequency heterogeneous Helmholtz equations[J]. Multiscale Modeling & Simulation, 2023, 21(3): 849-883.
[17] Li B Y, Li, Y L, Zheng W Y. A new perfectly matched layer method for the Helmholtz equation in nonconvex domains[J]. SIAM Journal on Applied Mathematics, 2023, 83(2): 666-694.
HETEROGENEOUS MULTISCALE – INTERIOR PENALTY DISCONTINUOUS GALERKIN METHOD FOR TWO-DIMENSIONAL HELMHOLTZ EQUATION WITH LOW WAVE NUMBER
*YU Tao, LI Jin-xin
(School of Mathematics and Physics, Jinggangshan University, Ji’an, Jiangxi 343009, China)
By combining the heterogeneous multiscale method (HMM) with the interior penalty discontinuous Galerkin method (IPDG), the heterogenous multiscale-interior penalty discontinuous Galerkin method (HMM-IPDG) is constructed for two-dimensional Helmholtz equation with low wave number. The optimal error estimation of the algorithm is given under the condition of micro period.
Helmholtz equation; low wave number; heterogenous multiscale method; interior penalty discontinuous Galerkin method; priori error estimate
1674-8085(2023)05-0001-05
O242.1
A
10.3969/j.issn.1674-8085.2023.05.001
2022-09-29;
2022-11-25
江西省教育廳科技計(jì)劃項(xiàng)目(GJJ211027);井岡山大學(xué)博士科研啟動項(xiàng)目(JZB1921)
*余 濤(1983-),男,江西萬安人,副教授,博士,主要從事多尺度建模研究(E-mail:yutao@jgsu.edu.cn).