Juan Blandon¹, Shinji Takaba², Toru Omae², Naoki Osawa¹, Hidekazu Murakawa³

CMES-Computer Modeling in Engineering & Sciences, Vol.106, No.1, pp. 53-75, 2015, DOI:10.3970/cmes.2015.106.053

Abstract Bending deformation of U-rib by gas heating is investigated using Thermal Elastic Plastic FEA employing an accurate heat source model. To validate our computational model, comparison between numerical analysis and experimental measurements are carried out. Good agreement is obtained for both temperature and deformation measurements. Inherent deformation method is employed to evaluate the overall behavior of U-rib under the influence of heating location and heating speed. Based on the prediction by FEA and using the inherent deformation method a new mathematical model describing the deformation of the U-rib is developed and evaluated for different combinations of heating conditions which can… More >

Ying Zhang¹, Lin Du¹, Xiaole Yue¹, Qun Han¹, Tong Fang²

CMES-Computer Modeling in Engineering & Sciences, Vol.106, No.1, pp. 37-51, 2015, DOI:10.3970/cmes.2015.106.037

Abstract The symmetry breaking bifurcation (SBB) phenomenon in a deterministic parameter Duffing system (DP-DS) is well known, yet the problem how would SBB phenomenon happen in a Duffing system with random parameter (RP-DS) is still open. For comparison study, the results for DP-DS are summarized at first: in short, SBB in DP-DS is just a transition of response phase trajectories from a single self-symmetric one about the origin into two mutual symmetric once, or vice versa. However, in DP-DS case, the two mutual symmetric phase trajectories are never commutable. In view of every sample of RP-DS is a DP-DS, we think… More >

Guochun Xu¹, S Yan², Q.W. Ma^1,2,3

CMES-Computer Modeling in Engineering & Sciences, Vol.106, No.1, pp. 1-35, 2015, DOI:10.3970/cmes.2015.106.001

Abstract In the Meshless Local Petrove-Galerkin based on Rankine source solution (MLPG-R), a simplified finite difference interpolation (SFDI) scheme was developed for numerical interpolation and gradient calculation (CMES, Vol. 23(2), pp. 75-89). Numerical tests concluded that the SFDI is generally as accurate as the linear moving least square method (MLS) but requires less CPU time. In this paper, a modified SFDI is proposed for numerically modelling of nonlinear water waves, considering the typical feature of the spatial variation of the wave-related parameters. Systematic numerical investigations are carried out and the results indicate that the modification considerably improves the robustness of the… More >

Chia-Ming Fan^1,2, Yu-Kai Huang¹, Po-Wei Li¹, Ying-Te Lee¹

CMES-Computer Modeling in Engineering & Sciences, Vol.105, No.6, pp. 491-515, 2015, DOI:10.3970/cmes.2015.105.491

Abstract In this paper, the boundary knot method (BKM) is adopted for accurately analyzing two-dimensional Stokes flows, dominated by viscous force and pressure gradient force. The Stokes flows, which denoted the flow fields with extremely viscous fluid or with very small velocity, appear in various engineering applications, such that it is very important to develop an efficient and accurate numerical method to solve the Stokes equations. The BKM, which can avoid the controversial fictitious boundary for sources, is an integral-free boundary-type meshless method and its solutions are expressed as linear combinations of nonsingular general solutions for Stokes equations. The weighting coefficients… More >

B. J. Zhu^1,2, Z. X. Hou¹, Y. F. Lu¹, S. Q. Shan¹

CMES-Computer Modeling in Engineering & Sciences, Vol.105, No.6, pp. 467-490, 2015, DOI:10.3970/cmes.2015.105.467

Abstract This paper mainly analyzes the dynamic soaring of UAV utilizing gradient wind. Dynamic soaring is an efficient path in which UAV absorbs energy from environment to enhance its flight endurance. A set of three-dimensional point dynamic equations for a soaring aircraft in three degrees of freedom is used in calculations. To simplify the calculation, the gradient wind’s direction is taken into decomposition. The notion of trajectory subsection analysis is applied to account for the energy transformation mechanism during the dynamic soaring, and the zone of direction is converted into cutting-in angle, which is regarded as initial limiting condition in the… More >

M. D. C. Magalhaes^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.105, No.6, pp. 441-465, 2015, DOI:10.3970/cmes.2015.105.441

Abstract The main goal of this study is to present an alternative and more efficient algorithm for a three-dimensional Component Mode Synthesis model to be used on sound transmission problems. The influence of fluid-structure interaction on airborne sound transmission problems is analysed using this model, which is based on simple volume geometries. In principle, the same procedure can also be applied when the component modes are obtained from alternative numerical techniques. The modal behaviour of acoustic volumes and a partition is implemented in two steps. The novelty of this alternative model is that the structural modes are incorporated on the acoustic… More >

H.Q. Nguyen¹, C.-D. Tran¹, T. Tran-Cong¹

CMES-Computer Modeling in Engineering & Sciences, Vol.105, No.5, pp. 399-439, 2015, DOI:10.3970/cmes.2015.105.399

Abstract In this paper, dynamic behaviours of dilute polymer solutions of various bead-spring chain models in shear flow are studied using a coarse-grained method based on the Integrated Radial Basis Function Networks (IRBFNs) and stochastic technique. The velocity field governed by the macroscopic conservation equations is determined by the IRBFN-based method, whereas the evolution of configurations of polymer chains governed by the diffusion stochastic differential equations are captured by the Brownian Configuration Field (BCF) approach. The system of micro-macro equations is closed by the Kramers’ expression, which allows for the determination of the polymer stresses in terms of BCF configurations. In… More >

W. M. Abd- Elhameed^1,2, Y. H. Youssri²

CMES-Computer Modeling in Engineering & Sciences, Vol.105, No.5, pp. 375-398, 2015, DOI:10.3970/cmes.2015.105.375

Abstract In this paper, a new spectral algorithm for solving linear and nonlinear fractional-order initial value problems is established. The key idea for obtaining the suggested spectral numerical solutions for these equations is actually based on utilizing the ultraspherical wavelets along with applying the collocation method to reduce the fractional differential equation with its initial conditions into a system of linear or nonlinear algebraic equations in the unknown expansion coefficients. The convergence and error analysis of the suggested ultraspherical wavelets expansion are carefully discussed. For the sake of testing the proposed algorithm, some numerical examples are considered. The numerical results indicate… More >

K. Sayevand¹, Yasir Khan², E. Moradi³, M. Fardi⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.105, No.5, pp. 361-373, 2015, DOI:10.3970/cmes.2015.105.361

Abstract In this study, the solitary wave solutions for third order equal-width wave-Burgers (EW-Burgers) equation, the second order Bratu and sinh-Bratu type equations will be discussed. The EW-Burgers equation models the propagation of nonlinear and dispersive waves with certain dissipative effects and furthermore the Bratu type problem appears a simplification of the solid fuel ignition model in thermal combustion theory. Our methodology, is investigated by using (G'/G)- expansion method. The obtained results can be extended to the other models. More >

Delfim Soares Jr.¹

CMES-Computer Modeling in Engineering & Sciences, Vol.105, No.5, pp. 341-360, 2015, DOI:10.3970/cmes.2015.105.341

Abstract In this work, a second-order time-marching procedure for dynamics is discussed, in which enhanced accuracy is enabled. The new technique is unconditionally stable (according to its parameter selection), it has no amplitude decay or overshooting, and it provides reduced period elongation errors. The method is based on displacement-velocity relations, requiring no computation of accelerations. It is efficient, simple and very easy to implement. Numerical results are presented along the paper, illustrating the good performance of the proposed technique. As it is described here, the new method has no drawbacks when compared to the Trapezoidal Rule (TR), which is one of… More >