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 >

Wen Zhao, Dongxing Mao^*, Zaixiu Jiang

Sound & Vibration, Vol.53, No.1, pp. 37-46, 2019, DOI:10.32604/sv.2019.04368

Abstract In order to analyze the effect of the background flow on the sound prediction of fine-scale turbulence noise, the sound spectra from static and flow environments are compared. It turns out that, the two methods can obtain similar predictions not only at 90 deg to the jet axis but also at mid- and high frequencies in other directions. The discrepancies of predictions from the two environments show that the effect of the jet flow on the sound propagation is related to low frequencies in the downstream and upstream directions. It is noted that there is an obvious advantage of computational… More >

F. Auricchio¹, L. Petrini², R. Pietrabissa³, E. Sacco⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.3&4, pp. 365-380, 2003, DOI:10.3970/cmes.2003.004.365

Abstract Since 80’s many devices were developed to exploit the unique blend of mechanical and biocompatibility properties of shape memory alloys in orthodontic applications. It results in a high clinical effectiveness, but also in a spreading of technical knowledge on the properties of the single appliances. The goal of the present contribution is to contrast this sense of bewilderness and to prepare the basis for a simulationtool able to support the orthodontist choice. In particular a finite-element beam with a one-dimensional constitutive law, able to describe the SMA super elasticity and shape memory effect, is presented: it is shown how computer… More >

Y.R. Li¹, L. Peng¹, W.Y. Shi¹, N. Imaishi²

FDMP-Fluid Dynamics & Materials Processing, Vol.2, No.3, pp. 153-166, 2006, DOI:10.3970/fdmp.2006.002.153

Abstract The convective instabilities in semiconduc-tor or oxide melts, significantly affect the quality oflarge crystals grown from the melts by the Czochralskimethod. This paper reviewsour recent numerical stud-ies of thermal convection in annular pools of low-Pr sili-con melt and moderate-Pr silicone oil. The mechanismsof the convective instability are discussed and the criticalconditions for the onset of three-dimensional flow are de-termined. The results show that the hydrothermal wave,characterized by curved spokes, is dominant in a shallowthin pool. In a thick pool of the low-Pr silicon melt, thereappears a standing wave type of oscillatory longitudinalrolls, which moves in the azimuthal direction and looksvery… More >

Jiegang Mou¹, Fengye Zhang^{1, *}, Haoshuai Wang¹, Denghao Wu¹

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.3, pp. 187-205, 2019, DOI:10.32604/fdmp.2019.04657

Abstract The self-priming process of a pump involves a complex gas-liquid two-phase flow. Studying the distribution of gas and water and the evolution of their flow in the pump is of great importance to optimize this process and shorten the pump self-priming time. In the present study, a standard k-ε turbulence model and a multiphase flow model have been used to simulate the self-priming pump process considering four different reflux hole areas. A comparison of the distribution of air and water distribution on the axial surface and inside the volume have been carried out for the different considered cases. The pattern… More >

A. Ja¹, A. Cheddadi¹

FDMP-Fluid Dynamics & Materials Processing, Vol.13, No.4, pp. 235-249, 2017, DOI:10.3970/fdmp.2017.013.235

Abstract This paper reports on the natural convection within a very narrow horizontal annular cavity filled with a porous medium saturated by a binary fluid. The main objective of this study is the identification of the effect of Lewis number on the flow structure and on the heat and mass transfer rates, in a cavity of very small radius ratio R=1.05, in the case of equal buoyancy forces (N=1), for a Rayleigh number Ra=50. The dimensionless governing equations were solved by the centered Finite Difference method using the ADI scheme. Several multicellular flows appear during the variation of the Lewis number,… More >

Yan Liu, Xiong Zhang, Yanping Lian

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.3, pp. 69-70, 2011, DOI:10.3970/icces.2011.018.069

Abstract The analyses of bird strike are of great concern to aircraft designers, because bird strikes can cause very serious problems to flight safety. Meshfree particle methods are suitable for simulating bird strike problems owing to their advantages in dealing with large deformation, fracture and fluid-structure interaction. The material point method (MPM) is employed to analyze the impacting of bird on windshield in this talk in which both the bird and the windshield are discretized by material points. The material model of the bird is accompanied by an appropriate equation of state (EOS) to model the flow behavior during impact, while… More >

P.F. Yang, X. Zhang, Y. Liu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.3, pp. 71-72, 2011, DOI:10.3970/icces.2011.017.071

Abstract The material point method (MPM) is extended to the simulations of material fragmentation due to detonation. A crack modeling scheme based on contact algorithm with material failure process is developed to study the dynamic crack propagation in plastic media. Particles after failure are transformed to a different velocity field by contact method, which makes the crack surface not constrained by grid lines and free to propagate dynamically in any direction even when the material experiences large plastic strain increments. The random characterization of the fragmentation can be described by both microscopic defect and macroscopic failure. When considering microscopic damage of… More >

Hongyang Li, Cheng Chen, WeiWei Li, Yanjing Zhang, Xiaopeng Liu, Yandong Wang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.2, pp. 47-48, 2011, DOI:10.3970/icces.2011.020.047

Abstract Large numbers of micro lattice plastic deformation of grains set up the macro plastic deformation of polycrystal metallic materials under different macro boundary condition. And the macro homogeneous deformation is in fact the statistical result of micro anisotropic lattice plastic flow. Both of the macro and micro deformation were influenced by intrinsic initial stress, which was intrinsic in the component from micro scale impurity to macro scale non-uniform deformation. In this paper, focused on the engineering application and further damage evaluation, effect of macro initial stress on the macro and micro plasticity deformation of sample under uniaxial tension was discussed… More >

Li Shan, Ming Cheng, Kaixin Liu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.3, pp. 87-88, 2011, DOI:10.3970/icces.2011.019.087

Abstract In the present paper, a combined scheme of discrete element method (DEM) and meshless method for numerical simulation of impact problems is proposed. Based on the basic principle of continuum mechanics, an axisymmetric DEM framework is estabilished for modeling the elastoplastic behavior of solid materials. A failure criterion is introduced to model the transformation from a continuum to a discontinuum. The friction force between contact elements is also considered after the failure appears. So our scheme can calculate not only the behavior of continuum and discontinuum, but also the transformation process from continuum to discontinuum. In addition, a meshless interpolation… More >