Daisuke Ishihara^*, Naoto Takayama

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.2, pp. 1237-1258, 2024, DOI:10.32604/cmes.2023.030211

Abstract In this study, we propose an algorithm selection method based on coupling strength for the partitioned analysis of structure-piezoelectric-circuit coupling, which includes two types of coupling or inverse and direct piezoelectric coupling and direct piezoelectric and circuit coupling. In the proposed method, implicit and explicit formulations are used for strong and weak coupling, respectively. Three feasible partitioned algorithms are generated, namely (1) a strongly coupled algorithm that uses a fully implicit formulation for both types of coupling, (2) a weakly coupled algorithm that uses a fully explicit formulation for both types of coupling, and (3) a partially strongly coupled and… More >

Guodong Zhang¹, Huifang Tao¹, Da Li¹, Kewei Chen², Guoxiang Li^1,*, Shuzhan Bai¹, Ke Sun^1,*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.1, pp. 219-237, 2024, DOI:10.32604/fdmp.2023.025566

Abstract A suitable channel structure can lead to efficient gas distribution and significantly improve the power density of fuel cells. In this study, the influence of two channel design parameters is investigated, namely, the ratio of the channel width to the bipolar plate ridge width (i.e., the channel ridge ratio) and the channel depth. The impact of these parameters is evaluated with respect to the flow pattern, the gas composition distribution, the temperature field and the fuel cell output capability. The results show that a decrease in the channel ridge ratio and an increase in the channel depth can effectively make… More >

Waris Ali¹, Asif Ali Shaikh¹, Feroz Shah¹, Sajjad Hussain^2,3,*

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.1, pp. 255-268, 2022, DOI:10.32604/cmes.2022.017313

Abstract A novel trapezoidal design for storage of heat energy through melting of phase-change material (PCM) is investigated. Latent heat thermal energy storage system (LHTES) is a promising option to diminish mis-match between energy consumption and supply. For this purpose, Paraffin: Rubitherm-35 (RT35) material is successively melted in aluminum structure which is heated from one side and the other sides are kept adiabatic. Melting of PCM is observed experimentally and melt fronts are photographed for various time lengths. The fluid-solid module in COMSOL Multiphysics 5.4 has been utilized. The transient heat conduction with enthalpy function is hired. Simulations are carried out… More >

Peter L. Bishay¹, Satya N. Atluri¹

CMC-Computers, Materials & Continua, Vol.33, No.1, pp. 19-62, 2013, DOI:10.3970/cmc.2013.033.019

Abstract In this paper, 2D and 3D Multiphysics Voronoi Cells (MVCs) are developed, for the Direct Mesoscale Numerical Simulation (DMNS) of the switching phenomena in ferroelectric polycrystalline materials. These arbitrarily shaped MVCs (arbitrary polygons in 2D, and arbitrary polyhedrons in 3D with each face being an arbitrary polygon) are developed, based on assuming radial basis functions to represent the internal primal variables (mechanical displacements and electric potential), and assuming linear functions to represent the primal variables on the element boundaries. For the 3D case, the linear functions used to represent the primal variables on each of the polygonal surfaces of the… More >

C. Delprete¹, F. Freschi², M. Repetto², C. Rosso¹

CMES-Computer Modeling in Engineering & Sciences, Vol.94, No.5, pp. 397-420, 2013, DOI:10.3970/cmes.2013.094.397

Abstract The growing necessity of accuracy in analyzing engineering problems requires more detailed and sophisticated models. Those models can include multiphysics interactions, that, sometimes, are highly nonlinear and the application of the superposition principle is then not possible. The cell method can be suitably used to study nonlinear multiphysics problems, because its theoretical framework for the physical laws is intrinsically multiphysics. In this way it is possible to take into account the mutual effects between different physics. Within the cell method framework, the coupling terms can be directly formulated in terms of the global variables used for the solution of the… More >

J. D. Hales¹, S. R. Novascone¹, R. L. Williamson¹, D. R. Gaston¹, M. R. Tonks¹

CMES-Computer Modeling in Engineering & Sciences, Vol.84, No.2, pp. 123-154, 2012, DOI:10.3970/cmes.2012.084.123

Abstract The equations governing solid mechanics are often solved via Newton's method. This approach can be problematic if the Jacobian determination, storage, or solution cost is high. These challenges are magnified for multiphysics applications. The Jacobian-free Newton-Krylov (JFNK) method avoids many of these difficulties through a finite difference approximation. A parallel, nonlinear solid mechanics and multiphysics application named BISON has been created that leverages JFNK. We overview JFNK, outline the capabilities of BISON, and demonstrate the effectiveness of JFNK for solid mechanics and multiphysics applications using a series of demonstration problems. We show that JFNK has distinct advantages in many cases. More >