Ruoyan Li^1,2, Wenjing Ye^1,*, Yijun Liu²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.32, No.1, pp. 1-1, 2024, DOI:10.32604/icces.2024.012150

Abstract A modern approach to control sound is through the development of sound-control materials/structures, which enable a wide range of applications such as noise reduction and non-contact particle manipulation. Designing these sound-controlling metamaterials requires accurate and efficient simulation methods for solving the unbounded acoustic wave equation with changing domain and frequencies. To facilitate the design optimization, surrogate models that are significantly more efficient than full-scale simulations are highly desirable. In this work, we present our recent work on the development of such surrogate models based on the concept of Fourier neural operators (FNO). FNO was originally… More >

Shangjun Gao^1,2, Yang Yang¹, Man Chen¹, Jian Zheng¹, Luqi Qin^2,*, Xiangyu Liu², Jianying Yang¹

Energy Engineering, Vol.121, No.11, pp. 3305-3329, 2024, DOI:10.32604/ee.2024.053622 - 21 October 2024

Abstract Horizontal well drilling and multi-stage hydraulic fracturing are key technologies for the development of shale gas reservoirs. Instantaneous acquisition of hydraulic fracture parameters is crucial for evaluating fracturing effectiveness, optimizing processes, and predicting gas productivity. This paper establishes a transient flow model for shale gas wells based on the boundary element method, achieving the characterization of stimulated reservoir volume for a single stage. By integrating pressure monitoring data following the pumping shut-in period of hydraulic fracturing for well testing interpretation, a workflow for inverting fracture parameters of shale gas wells is established. This new method… More >

Ruijin Huo^1,2,3, Qingxiang Pei^1,2,3, Xiaohui Yuan^1,*, Yanming Xu³

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.2, pp. 2053-2077, 2024, DOI:10.32604/cmes.2024.049185 - 20 May 2024

Abstract In this paper, a generalized th-order perturbation method based on the isogeometric boundary element method is proposed for the uncertainty analysis of broadband structural acoustic scattering problems. The Burton-Miller method is employed to solve the problem of non-unique solutions that may be encountered in the external acoustic field, and the th-order discretization formulation of the boundary integral equation is derived. In addition, the computation of loop subdivision surfaces and the subdivision rules are introduced. In order to confirm the effectiveness of the algorithm, the computed results are contrasted and analyzed with the results under Monte More >

Xue Liang^1,2, Linjuan Wang^3,*

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.3, pp. 2807-2834, 2024, DOI:10.32604/cmes.2024.046770 - 11 March 2024

Abstract The peridynamics (PD), as a promising nonlocal continuum mechanics theory, shines in solving discontinuous problems. Up to now, various numerical methods, such as the peridynamic mesh-free particle method (PD-MPM), peridynamic finite element method (PD-FEM), and peridynamic boundary element method (PD-BEM), have been proposed. PD-BEM, in particular, outperforms other methods by eliminating spurious boundary softening, efficiently handling infinite problems, and ensuring high computational accuracy. However, the existing PD-BEM is constructed exclusively for bond-based peridynamics (BBPD) with fixed Poisson’s ratio, limiting its applicability to crack propagation problems and scenarios involving infinite or semi-infinite problems. In this paper,… More >

Hasna Akarni^*, Hamza Mabchour, Laila El Aarabi, Soumia Mordane

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.3, pp. 579-593, 2024, DOI:10.32604/fdmp.2023.043080 - 12 January 2024

Abstract In this study, we focus on the numerical modelling of the interaction between waves and submerged structures in the presence of a uniform flow current. Both the same and opposite senses of wave propagation are considered. The main objective is an understanding of the effect of the current and various geometrical parameters on the reflection coefficient. The wave used in the study is based on potential theory, and the submerged structures consist of two rectangular breakwaters positioned at a fixed distance from each other and attached to the bottom of a wave flume. The numerical More >

Chuang Lu¹, Leilei Chen^2,3, Jinling Luo⁴, Haibo Chen^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.1, pp. 847-872, 2024, DOI:10.32604/cmes.2023.044446 - 30 December 2023

Abstract We propose a combined shape and topology optimization approach in this research for 3D acoustics by using the isogeometric boundary element method with subdivision surfaces. The existing structural optimization methods mainly contain shape and topology schemes, with the former changing the surface geometric profile of the structure and the latter changing the material distribution topology or hole topology of the structure. In the present acoustic performance optimization, the coordinates of the control points in the subdivision surfaces fine mesh are selected as the shape design parameters of the structure, the artificial density of the sound… More >

Zonglin Li^1,2, Zhenyu Gao², Yijun Liu^2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.3, pp. 2159-2175, 2024, DOI:10.32604/cmes.2023.030920 - 15 December 2023

Abstract The boundary element method (BEM) is a popular method for solving acoustic wave propagation problems, especially those in exterior domains, owing to its ease in handling radiation conditions at infinity. However, BEM models must meet the requirement of 6–10 elements per wavelength, using the conventional constant, linear, or quadratic elements. Therefore, a large storage size of memory and long solution time are often needed in solving higher-frequency problems. In this work, we propose two new types of enriched elements based on conventional constant boundary elements to improve the computational efficiency of the 2D acoustic BEM.… More > Graphic Abstract

Yongtong Zheng^1,* , Yijun Liu¹, Xiaowei Gao^1,2,3

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.3, pp. 1-1, 2023, DOI:10.32604/icces.2023.09774

Abstract Recently, a series of isoparametric boundary elements have been constructed to simulate the shape of holes, tubes, disks, rings and spheres based on the Lagrange interpolation formulation and the closure condition at two ends of an arc. These elements can simulate the models which contain the shapes mentioned above with less nodes and less elements than the conventional boundary elements. However, the basis of those elements, i.e., hole elements, have the poor accuracy when the number of nodes is less than 6. To improve these elements, two kinds of improvements are proposed in this study.… More >

Yujing Ma¹, Zhongwang Wang², Xiaohui Yuan¹, Leilei Chen^2,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.2, pp. 1-2, 2023, DOI:10.32604/icces.2023.09662

Abstract The paper presents a novel fast calculation method for broadband Electromagnetic Scattering analysis. In this work, the isogeometric boundary element method is used to solve Helmholtz equations for the electromagnetic scattering problems. The non-uniform rational B-splines are employed to construct structural geometries and discretize electric and magnetic field integral equations [1,2]. To avoid timeconsuming multi-frequency calculations, the series expansion method is used to decouple the frequencydependent terms from the integrand in the boundary element method [3,4]. The second-order Arnoldi (SOAR) method is applied to construct a reduced-order model that retains the essential structures and key More >

Ruoyan Li^1,2, Yijun Liu^1,*, Wenjing Ye²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.1, pp. 1-1, 2023, DOI:10.32604/icces.2023.09472

Abstract The boundary element method (BEM) for acoustic problems is a numerical method based on solving the discretized boundary integral equation (BIE) corresponding to the Helmholtz equation. A fast direct BEM for 3D acoustic problems is proposed in this paper, which is more suitable for broadband acoustic simulation of complex structures, such as in the design and analysis of acoustic metamaterials. The main idea of the fast direct solver is based on the hierarchical off-diagonal low-rank (HODLR) matrix, randomized interpolative decomposition and fast matrix inversion formula. Several numerical examples in solving both interior and exterior acoustic More >