Srikrishna Sahu¹, K. Muralidhar¹, P.K. Panigrahi¹

FDMP-Fluid Dynamics & Materials Processing, Vol.3, No.3, pp. 265-286, 2007, DOI:10.3970/fdmp.2007.003.265

Abstract Convection in a differentially heated cavity partly filled with silicone oil has been experimentally studied. The air-oil layers are subjected to a temperature difference in the vertical direction, with the lower wall being heated with respect to the top. The overall geometry is that of an enclosed cavity that is octagonal in plan. Heights of oil layers considered for experiments correspond to 30, 50, and 70% of the vertical cavity dimension. Measurements have been carried out using a shadowgraph technique. A limited number of interferograms have also been recorded. The shadowgraph technique has been validated against interferograms under identical experimental… More >

Mark Sussman¹, Mitsuhiro Ohta²

FDMP-Fluid Dynamics & Materials Processing, Vol.3, No.1, pp. 21-36, 2007, DOI:10.3970/fdmp.2007.003.021

Abstract In this paper, we describe new techniques for numerically approximating two-phase flows. Specifically, we present new techniques for treating the viscosity and surface tension terms that appear in the Navier-Stokes equations for incompressible two-phase flow. Our resulting numerical method has the property that results computed using our two-phase algorithm approach the corresponding "one-phase'' algorithm in the limit of zero gas density/viscosity; i.e. the two-phase results approach the one-phase free-boundary results in the limit that the gas is assumed to become a uniform pressure void. By grid convergence checks and comparison with previous experimental data, we shall demonstrate the advantages of… More >

B. Yang², V. K. Tewary³

CMC-Computers, Materials & Continua, Vol.8, No.1, pp. 23-32, 2008, DOI:10.3970/cmc.2008.008.023

Abstract A three-dimensional Green's function for a material system consisting of anisotropic and linearly elastic planar multilayers with interfacial membrane and flexural rigidities has been derived. The Stroh formalism and two-dimensional Fourier transforms are applied to derive the general solution for each homogeneous layer. The Green's function for the multilayers is then solved by imposing the surface boundary condition, the interfacial displacement continuity condition, and the interfacial traction discontinuity condition. The last condition is given by the membrane and bending equilibrium equations of the interphases modeled as Kirchhoff plates. Numerical results that demonstrate the validity and efficiency of the formulation are… More >

G. Mishuris¹, A. Öchsner², G. Kuhn³

CMC-Computers, Materials & Continua, Vol.4, No.3, pp. 137-152, 2006, DOI:10.3970/cmc.2006.004.137

Abstract Nonclassical transmission conditions for dissimilar elastic structures with imperfect interfaces are investigated. The thin interface zone is assumed to be soft or stiff in comparison with the bonded materials and the transmission conditions for stiff interfaces are evaluated based on asymptotic analysis. The accuracy of the transmission conditions is clarified not only in terms of asymptotic estimate, but, which is especially important for users, also in values by accurate FEM calculations. The ranges of applicability of the conditions are discussed. More >

Guoquan Nie^{1, *}, Menghe Wang¹

CMC-Computers, Materials & Continua, Vol.59, No.1, pp. 257-274, 2019, DOI:10.32604/cmc.2019.04498

Abstract Propagation characteristics of Rayleigh-type wave in a piezoelectric layered system are theoretically investigated. The piezoelectric layer is considered as a cubic crystal with finite thickness rotated about Y-axis and is imperfectly bonded onto a semi-infinite dielectric substrate. The imperfect interface between the two constituents is assumed to be mechanically compliant and dielectrically weakly conducting. The exact dispersion relations for electrically open or shorted boundary conditions are obtained. The numerical results show that the phase velocity of Rayleigh-type wave is symmetric with respect to the cut orientation of 45。 and can achieve the maximum propagation speed in this orientation. The mechanical… More >

Yu Zhang^1,2,*, Mengxing Huang^1,2,*, Hao Wang³, Wenlong Feng^1,2, Jieren Cheng^1,2, Hui Zhou^1,2

CMC-Computers, Materials & Continua, Vol.58, No.1, pp. 287-306, 2019, DOI:10.32604/cmc.2019.03736

Abstract Cyber-Physical Systems (CPS) tightly integrate cyber and physical components and transcend traditional control systems and embedded system. Such systems are often mission-critical; therefore, they must be high-assurance. High-assurance CPS require co-verification which takes a comprehensive view of the whole system to verify the correctness of a cyber and physical components together. Lack of strict multiple semantic definition for interaction between the two domains has been considered as an obstacle to the CPS co-verification. A Cyber/Physical interface model for hierarchical a verification of CPS is proposed. First, we studied the interaction mechanism between computation and physical processes. We further classify the… More >

M. Ozisik^1,*, M. A. Mehdiyev², S. D. Akbarov^2,3

CMC-Computers, Materials & Continua, Vol.54, No.2, pp. 103-136, 2018, DOI:10.3970/cmc.2018.054.103

Abstract The dynamics of the moving-with-constant-velocity internal pressure acting on the inner surface of the hollow circular cylinder surrounded by an infinite elastic medium is studied within the scope of the piecewise homogeneous body model by employing the exact field equations of the linear theory of elastodynamics. It is assumed that the internal pressure is point-located with respect to the cylinder axis and is axisymmetric in the circumferential direction. Moreover, it is assumed that shear-spring type imperfect contact conditions on the interface between the cylinder and surrounding elastic medium are satisfied. The focus is on the influence of the mentioned imperfectness… More >

Surkay D. Akbarov^{1, 2, *}, Mahir A. Mehdiyev³

CMC-Computers, Materials & Continua, Vol.54, No.1, pp. 61-81, 2018, DOI:10.3970/cmc.2018.054.061

Abstract The paper develops and employs analytical-numerical solution method for the study of the time-harmonic dynamic stress field in the system consisting of the hollow cylinder and surrounding elastic medium under the non-axisymmetric forced vibration of this system. It is assumed that in the interior of the hollow cylinder the point-located with respect to the cylinder axis, non-axisymmetric with respect to the circumferential direction and uniformly distributed time-harmonic forces act. Corresponding boundary value problem is solved by employing of the exponential Fourier transformation with respect to the axial coordinate and by employing of the Fourier series expansion of these transformations. Numerical… More >

ZichunYang¹, Gaohui Su^1,2, Bin Chen¹

CMC-Computers, Materials & Continua, Vol.51, No.1, pp. 43-62, 2016, DOI:10.3970/cmc.2016.051.043

Abstract The molecular dynamics (MD) simulations were used to understand the heat transfer process between the gas phase and the solid skeleton in the nanoporous silica aerogels. The amorphous silica nanoparticles were generated by the MD simulations and the energy accommodation coefficient (EAC) between the gases and the nanoparticles was calculated based on the results of the nonequilibrium molecular dynamics (NEMD) simulations. The apparent thermal conductivity (ATC) of the gases between the heat source and heat sink was also obtained. The effects of the temperature, the particle diameter and the molecule type on the EAC and the ATC were investigated. The… More >

CMC-Computers, Materials & Continua, Vol.47, No.3, pp. 179-201, 2015, DOI:10.3970/cmc.2015.047.179

Abstract Discontinuous smoothed particle hydrodynamics (DSPH) method based on traditional SPH method, which can be used to simulate discontinuous physics problems near interface or boundary. Previous works showed that DSPH method has a good application prospect [Xu et al, 2013], but further verification and improvement are demanded. In this paper, we investigate the accuracy of DSPH method by some numerical models. Moreover, to improve the accuracy of DSPH method, first order and second order multidimensional RDSPH methods are proposed by following the idea of restoring particle consistency in SPH (RSPH) method which has shown good results in the improvement of particle… More >