K. Kuramoto¹, M. Furuichi², K. Kakuda²

CMES-Computer Modeling in Engineering & Sciences, Vol.106, No.3, pp. 169-186, 2015, DOI:10.3970/cmes.2015.106.169

Abstract This paper describes a scheme to improve efficiency of multi-agent simulation system (MAS) on single computer that has multiple processor cores. Simulation technology is applied for broad usage in the world, and MAS gathers attention from the fields that treat complicated and non-numeric issues such as traffic analysis, analyzing evacuation from a building, and defense training. Since the requirements of simulation scale and fidelity are growing, the importance of their performance is also increasing. However, CPU clock speedup is slowing, and improvement of computer performance has come to depend on the number of processors, cores, and graphics processing units. Consequently,… More >

M. Toujani¹, R. Djebali², L. Hassini¹, S. Azzouz¹, A. Belghith¹

CMES-Computer Modeling in Engineering & Sciences, Vol.98, No.5, pp. 469-485, 2014, DOI:10.3970/cmes.2014.098.469

Abstract In the present work we aim to simulate unsteady two-dimensional evolution of the moisture content, temperature and mechanical stress in a parallelepiped apple sample during convective drying. The model is based on the heat and mass transfer equations and the mechanical equilibrium equation under the assumptions of plane deformation, viscoelasticity and isotropic hydric shrinkage. The Finite Elements COMSOL Multiphysics solver is used to solve the developed model. The hydro-thermal model was validated on experimental data drawn in our laboratory for moisture and temperature internal profiles of the product. Excellent agreement has been obtained between numerical and measured data for different… More >

Shueei-Muh Lin¹, Min-Jun Teng²

CMES-Computer Modeling in Engineering & Sciences, Vol.103, No.3, pp. 189-213, 2014, DOI:10.3970/cmes.2014.103.189

Abstract The control and separation of a scanning device moving along an arbitrary trajectory on an elastic plate is investigated. The system is a moving mass problem and is difficult to analyze directly. A semi-analytical method for the movingmass model is presented here. Without vibration control, the separation of a vehicle from a plate is likely to happen. The mechanism of separation of a vehicle from a plate is studied. Moreover, the effects of several parameters on vibration separation and the critical speed of system are studied. An effective control methodology is proposed for suppressing vibration and separation This model is… More >

Yidong Bao^1,2, Dongmei Wu^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.100, No.4, pp. 277-294, 2014, DOI:10.3970/cmes.2014.100.277

Abstract Aiming at the shortcomings of mass-spring model, this paper, on the basis of preliminary studies, established a new viscoelastic soft tissue model based on meshless structure. The model is consisted of a large quantity of filled spheres, with every three spheres being connected by a spring and a Kelvin structure, which can further enhance the real-time virtual simulation operability while ensure the viscoelasticity of basic model. The stress relaxation and creep equation of the model can be derived from formula derivation. Through setting different parameters to the filled spheres, this model, with certain universal property, can create a virtual liver,… More >

Xuejun Hou^1,2, Deli Gao^1,3, Zhonghou Shen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.90, No.1, pp. 1-16, 2013, DOI:10.3970/cmes.2013.090.001

Abstract Diesel tail gas drilling (DTGD) is a type of gas drilling, which uses diesel tail gas (DTG) as a circulating medium. Its cost is slightly higher than that of air drilling, but is cheaper than those of nitrogen drilling and natural gas drilling. When the reservoir is drilled with DTG, just as nitrogen and natural gas, the DTG will prevent the burning and blasting of oil and gas in the bottom hole. In order to reduce costs, the DTG is often used in drilling the reservoir, to prevent the underground explosion. This paper analyzes the composition of the Z12V190 diesel… More >

Y.J. Ning^1,2,3, Z.Y. Zhao³, J.P. Sun³, W.F. Yuan^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.89, No.3, pp. 221-262, 2012, DOI:10.3970/cmes.2012.089.221

Abstract In this paper, wave propagations in jointed rock masses are modeled by the discontinuous deformation analysis (DDA) method. The selection of the numerical control parameters in the DDA for wave propagation modeling is discussed in detail, and the effects of the joint stiffness, the seismic loading frequency, the joint strength, and the incident angle on the propagations of stress waves in a jointed rock mass are modeled and analyzed. Two nonreflecting boundary conditions including the viscous boundary condition (VBC) and the superposition boundary condition (SBC) are coupled into the DDA. The applicability of the two nonreflecting boundary conditions for simple… More >

Paola Gardano¹, Peter Dabnichki^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.15, No.2, pp. 87-98, 2006, DOI:10.3970/cmes.2006.015.087

Abstract The work presents a numerical simulation of hydrodynamic forces generated in front crawl swimming. The three dimensional Laplace's equation is used for the analysis of the flow around a moving body in an infinite domain and considers the effect of the added mass and the acceleration on the hydrodynamic forces (Drag and Lift) generated by the interaction between the flow and the body at different geometric configurations of the arm -- variable elbow angle. Boundary Element Method (BEM) was used to obtain the solution of the three dimensional equation numerically. The aim of the work was two-fold:
1) to… More >

Souli M.¹, Bouamoul A.², Nguyen-Dang T.V.³

CMES-Computer Modeling in Engineering & Sciences, Vol.86, No.5, pp. 469-486, 2012, DOI:10.3970/cmes.2012.086.469

Abstract Protection of military vehicles against blast mine and high explosive in air is of a great concern in defence industry. Anti-Vehicle (AV) mines and Improvised Explosive Devices (IED's) are capable of inflecting damage to heavy vehicles. For the last decades, numerical simulation of blast wave propagation and its interaction with surrounding structures becomes more and more the focus of computational engineering, since experimental tests are very expensive and time consuming. This paper presents an experimental and numerical investigation of blast wave propagation in air, using an Arbitrary Lagrangian Eulerian (ALE) multi-material formulation developed in LS-DYNA with the contribution of the… More >

Wei-Chung Tien¹, Yue-Tzu Yang¹, Cha’o-Kuang Chen^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.85, No.5, pp. 447-462, 2012, DOI:10.3970/cmes.2012.085.447

Abstract Both buoyancy effects of thermal and mass diffusion in the natural convection flow about a vertical plate are considered in this paper. The non-linear coupled differential governing equations for velocity, temperature and concentration fields are solved by using the homotopy analysis method. Without the need of iteration, the obtained solution is in the form of an infinite power series which indicates those series have high accuracy when comparing it with other-generated by the traditional method. The impact of the Prandtl number, Schmidt number and the buoyancy parameter on the flow are widely discussed in detail. More >

W.A. El-Askary^1,2, A. Balabel², S.M. El-Behery², A. Hegab³

CMES-Computer Modeling in Engineering & Sciences, Vol.82, No.1, pp. 29-54, 2011, DOI:10.32604/cmes.2011.082.029

Abstract In the present paper, the characteristics of compressible turbulent flow in a porous channels subjected to either symmetric or asymmetric mass injection are numerically predicted. A numerical computer-program including different turbulence models has been developed by the present authors to investigate the considered flow. The numerical method is based on the control volume approach to solve the governing Reynolds-Averaged Navier-Stokes (RANS) equations. Turbulence modeling plays a significant role here, in light of the complex flow generated, so several popular engineering turbulence models with good track records are evaluated, including five different turbulence models. Numerical results with available experimental data showed… More >