Yujing Ma^1,4, Zhongwang Wang², Jieyuan Zhang³, Ruijin Huo^1,4, Xiaohui Yuan^1,4,*

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.2, pp. 2079-2102, 2024, DOI:10.32604/cmes.2024.048488

Abstract In this paper, an adaptive polynomial chaos expansion method (PCE) based on the method of moments (MoM) is proposed to construct surrogate models for electromagnetic scattering and further sensitivity analysis. The MoM is applied to accurately solve the electric field integral equation (EFIE) of electromagnetic scattering from homogeneous dielectric targets. Within the bistatic radar cross section (RCS) as the research object, the adaptive PCE algorithm is devoted to selecting the appropriate order to construct the multivariate surrogate model. The corresponding sensitivity results are given by the further derivative operation, which is compared with those of More >

Dong Pan¹, Xu Gui¹, Jiayin Xu¹, Yuming Shen¹, Haoran Xu², Yinghao Ma^2,*

Energy Engineering, Vol.121, No.5, pp. 1309-1328, 2024, DOI:10.32604/ee.2024.046464

Abstract With the increasing urgency of the carbon emission reduction task, the generation expansion planning process needs to add carbon emission risk constraints, in addition to considering the level of power adequacy. However, methods for quantifying and assessing carbon emissions and operational risks are lacking. It results in excessive carbon emissions and frequent load-shedding on some days, although meeting annual carbon emission reduction targets. First, in response to the above problems, carbon emission and power balance risk assessment indicators and assessment methods, were proposed to quantify electricity abundance and carbon emission risk level of power planning… More >

Jianlong Jin, Jingjing Ding, Long Xiong, Ming Bao, Peng Zeng^*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.4, pp. 803-814, 2024, DOI:10.32604/fdmp.2023.027311

Abstract The effects of different contents of a MgO expansive agent and phosphorus slag on the mechanical properties, shrinkage behavior, and the heat of hydration of concrete were studied. The slump flow, setting time, dry shrinkage, and hydration heat were used as sensitive parameters to assess the response of the considered specimens. As shown by the results, in general, with an increase in the phosphorus slag content, the hydration heat of concrete decreases for all ages, but the early strength displays a downward trend and the dry shrinkage rate increases. The 90-d strength and dry shrinkage More > Graphic Abstract

Haitao Liu^1,2,*, Jiaming Wang¹, Xiuliang Zhang¹, Yanji Jiang², Qian Xiao¹

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.3, pp. 2747-2772, 2024, DOI:10.32604/cmes.2024.047129

Abstract The expansion chamber serves as the primary silencing structure within the exhaust pipeline. However, it can also act as a sound-emitting structure when subjected to airflow. This article presents a hybrid method for numerically simulating and analyzing the unsteady flow and aerodynamic noise in an expansion chamber under the influence of airflow. A fluid simulation model is established, utilizing the Large Eddy Simulation (LES) method to calculate the unsteady flow within the expansion chamber. The simulation results effectively capture the development and changes of the unsteady flow and vorticity inside the cavity, exhibiting a high… More > Graphic Abstract

Yujing Ma^1,*, Leilei Chen^2,3, Haojie Lian^3,4, Zhongwang Wang^2,3

The International Conference on Computational & Experimental Engineering and Sciences, Vol.28, No.1, pp. 1-1, 2023, DOI:10.32604/icces.2023.010585

Abstract An efficient method of moments (MoM) based on polynomial chaos expansion(PCE) is applied to quickly calculate the electromagnetic scattering problems. The triangle basic functions are used to discretize the surface integral equations. The PCE is utilized to accelerate the MoM by constructing a surrogate model for univariate and bivariate analysis[1]. The mathematical expressions of the surrogate model for the radar cross-section (RCS) are established by considering uncertain parameters such as bistatic angle, incident frequency, and dielectric constant[2,3]. By using the example of a scattering cylinder with analytical solution, it is verified that the MoM accelerated More >

Xiaozhou Xia¹, Changsheng Qin¹, Guangda Lu², Xin Gu^1,*, Qing Zhang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.3, pp. 2257-2276, 2024, DOI:10.32604/cmes.2023.031238

Abstract Accurate simulation of the cracking process caused by rust expansion of reinforced concrete (RC) structures plays an intuitive role in revealing the corrosion-induced failure mechanism. Considering the quasi-brittle fracture of concrete, the fracture phase field driven by the compressive-shear term is constructed and added to the traditional brittle fracture phase field model. The rationality of the proposed model is verified by a mixed fracture example under a shear displacement load. Then, the extended fracture phase model is applied to simulate the corrosion-induced cracking process of RC. The cracking patterns caused by non-uniform corrosion expansion are… More >

Hsiu-Hung Chen^a , Yuan Zhao^b, Chung-Lung Chen^a,*

Frontiers in Heat and Mass Transfer, Vol.4, No.1, pp. 1-7, 2013, DOI:10.5098/hmt.v4.1.3004

Abstract Carbon-based materials draw more and more attention from both academia and industry: its allotropes, including graphene nanoplatlets, graphite nanoplatlets and carbon nanotubes, can readily enhance thermal conductivity of thermal interface products when served as fillers. Structuraloptimization in micro/nano-scale has been investigated and expected to finely tune the coefficient of thermal expansion (CTE) of thermal interface materials (TIMs). The capability of adjusting CTE of materials greatly benefits the design of interface materials as CTE mismatch between materials may result in serious fatigue at the interface region that goes through thermal cycles. Recently, a novel nano-thermal-interface material… More >

A. Vijayalakshmi, S. Srinivas^*

Frontiers in Heat and Mass Transfer, Vol.7, pp. 1-11, 2016, DOI:10.5098/hmt.7.10

Abstract In the present study, the flow and heat transfer characteristics of a nanofluid in an expanding or contracting porous channel with different permeabilities in presence of thermal radiation are investigated. Analytical solutions for the flow variables are obtained by employing homotopy analysis method (HAM). Maxwell-Garnetts and Brinkman models are considered to calculate the thermal conductivity and the viscosity of nanofluid. In this investigation, we considered water and ethylene glycol as base fluids and silver ( Ag ), copper ( Cu ), titanium dioxide ( TiO₂ ) and alumina ( Al₂O₃ ) as nanoparticles. The effects of various More >

Zi Han^1,*, Zhentian Huang²

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.1, pp. 245-272, 2024, DOI:10.32604/cmes.2023.029708

Abstract In the context of global mean square error concerning the number of random variables in the representation, the Karhunen–Loève (KL) expansion is the optimal series expansion method for random field discretization. The computational efficiency and accuracy of the KL expansion are contingent upon the accurate resolution of the Fredholm integral eigenvalue problem (IEVP). The paper proposes an interpolation method based on different interpolation basis functions such as moving least squares (MLS), least squares (LS), and finite element method (FEM) to solve the IEVP. Compared with the Galerkin method based on finite element or Legendre polynomials,… More > Graphic Abstract

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 >