Subhankar Sen¹, Sanjay Mittal^{2, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.113, No.1, pp. 35-55, 2017, DOI:10.3970/cmes.2017.113.033

Abstract The evolution of far wake of stationary elliptic cylinders with angle of attack is investigated for the unsteady flow at Re = 200 using a stabilized finite- element method. The Reynolds number, Re, is based on the major axis of cylinder and free-stream speed. Cylinder aspect ratios, AR considered are 0.2, 0.5 and 0.8 while the angle of attack, α varies from 0◦ to 90◦. With increasing α, the Karman or primary shedding frequency of each cylinder decreases monotonically while the primary wavelength and time-averaged as well as r.m.s. drag increase monoton- ically. The time-averaged… More >

Niki Rezazadeh, Rezvan Abdi^*

Frontiers in Heat and Mass Transfer, Vol.7, pp. 1-6, 2016, DOI:10.5098/hmt.7.30

Abstract This study investigates the heat transfer in the mode of natural convection from a pair of hot cylinders to a cold square enclosure. Effects of boundary conditions of the enclosure on the rate of heat transfer from a pair of isothermal hot cylinders are investigated at a Rayleigh number of 10⁵ . The cylinders are arranged in a horizontal array at the middle height of enclosure. The commercial software, Fluent (V.6.3.26), is utilized to solve the problem using the Finite Volume Method. The streamlines as well as isothermal lines of the problem are reported. Moreover, the More >

Da-guo Wang^1,2, Bin Hu¹, Qing-xiang Shui¹

CMES-Computer Modeling in Engineering & Sciences, Vol.107, No.4, pp. 297-320, 2015, DOI:10.3970/cmes.2015.107.297

Abstract A numerical large eddy simulation (LES) method combined with the characteristic-based operator-splitting finite element method is proposed. The subgrid eddy viscosity model is used to calculate sub-grid stress in LES. In each time step, the governing equations are split into diffusive and convective parts. The convective part is first discretized by using the characteristic Galerkin method and then solved explicitly. The backward-facing step flow and the flow past a single cylinder are adopted to validate the model. Results agree with existing numerical results or experimental data. The flow past two cylinders in tandem arrangement is More >

Chih-Ping Wu, Ruei-Yong Jiang

CMC-Computers, Materials & Continua, Vol.46, No.1, pp. 17-56, 2015, DOI:10.3970/cmc.2015.046.017

Abstract An asymptotic meshless method using the differential reproducing kernel (DRK) interpolation and multiple time scale methods is developed for the three-dimensional (3D) free vibration analysis of sandwich functionally graded material (FGM) circular hollow cylinders with combinations of simply-supported and clamped edge conditions. In the formulation, we perform the mathematical processes of nondimensionalization, asymptotic expansion and successive integration to obtain recurrent sets of motion equations for various order problems. Classical shell theory (CST) is derived as a first-order approximation of the 3D elasticity theory, and the motion equations for higher-order problems retain the same differential operators… More >

S.D. Akbarov ^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.97, No.5, pp. 407-424, 2014, DOI:10.3970/cmes.2014.097.407

Abstract Flexural wave dispersion in a bi-material solid and hollow circular cylinders is investigated with the use of the three-dimensional linear theory of elastodynamics. It is assumed that on the interface surface of the cylinders the complete contact conditions satisfy. The analytical solution of the corresponding field equations is presented and, using these solutions, the dispersion equations for the cases under consideration are obtained. The dispersion equations are solved numerically and based on these solutions, dispersion curves are constructed for the concrete selected pairs of materials such as Tungsten (inner cylinder material) + Aluminum (outer cylinder More >

Chih-Ping Wu^1,2, Ruei-Yong Jiang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.97, No.3, pp. 239-279, 2014, DOI:10.3970/cmes.2014.097.239

Abstract A state space differential reproducing kernel (DRK) method is developed for the three-dimensional (3D) buckling analysis of simply-supported, carbon nanotube-reinforced composite (CNTRC) circular hollow cylinders and laminated composite ones under axial compression. The single-walled carbon nanotubes (CNTs) and polymer are used as the reinforcements and matrix, respectively, to constitute the CNTRC cylinder. Three different distributions of CNTs varying in the thickness direction are considered (i.e., the uniform distribution and functionally graded rhombus-, and X-type ones), and the through-thickness distributions of effective material properties of the cylinder are determined using the rule of mixtures. The 3D… More >

Chih-Ping Wu^1,2, Ruei-Yong Jiang¹, Sheng-Yao Tu¹

CMC-Computers, Materials & Continua, Vol.41, No.2, pp. 111-152, 2014, DOI:10.3970/cmc.2014.041.111

Abstract Exact three-dimensional stability and free vibration analyses of simply-supported, multilayered functionally graded material (FGM) circular hollow cylinders and laminated composite ones under axial compression are presented. The material properties of each FGM layer are assumed to obey a power-law distribution of the volume fractions of constituents through the thickness coordinate. The Pagano method, which is based on the principle of virtual displacement and is conventionally used for the analysis of laminated composite structures, is modified to be feasible for the study of multilayered FGM cylinders, in which Reissner's mixed variational theorem, the successive approximation and… More >

Seyed Mahmoud Hosseini ¹

CMES-Computer Modeling in Engineering & Sciences, Vol.95, No.1, pp. 1-29, 2013, DOI:10.3970/cmes.2013.095.001

Abstract In this article, the effects of carbon nanotubes distributions on natural frequency are studied for a functionally graded nanocomposite thick hollow cylinder reinforced by single-walled carbon nanotubes using a hybrid mesh-free method. The FG nanocomposite cylinder is excited by a shock loading, which is applied on the inner surface of cylinder. The first natural frequency is obtained for various nonlinear grading patterns of distributions of the aligned carbon nanotubes. The effects of various nonlinear grading patterns on natural frequency are obtained and discussed in details. The presented hybrid mesh-free method is based on the generalized More >

S. D. Akbarov^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.92, No.4, pp. 387-421, 2013, DOI:10.3970/cmes.2013.092.387

Abstract Flexural wave dispersion in finitely pre-stretched (or pre-compressed) solid and hollow, circular cylinders is investigated with the use of the threedimensional linearized theory of elastic waves in initially stressed bodies. It is assumed that the initial strains in the cylinders are homogeneous and correspond to the uniaxial tension, or compression, along their central axes. The elasticity relations of the cylinders’ materials are described by the harmonic potential. The analytical solution of the corresponding field equations is presented and, using these solutions, the dispersion equations for the cases under consideration are obtained. The dispersion equations are… More >

S.M. Moussavinezhad¹, Farzad Shahabian¹, Seyed Mahmoud Hosseini^2,3

CMES-Computer Modeling in Engineering & Sciences, Vol.91, No.3, pp. 177-204, 2013, DOI:10.3970/cmes.2013.091.177

Abstract In this article, the propagation of elastic wave is studied in two dimensional functionally graded thick hollow cylinder with finite length subjected to mechanical shock loading, considering two dimensional variations for mechanical properties. The meshless local Petrov-Galerkin (MLPG) method is developed to solve the boundary value problem. The Newmark finite difference method is used to treat the time dependence of the variables for transient problems. The FG cylinder is considered to be under axisymmetric conditions. The mechanical properties of FG cylinder are assumed to vary across thickness and length of FG cylinder in terms of… More >