Open Access
ARTICLE
Subhankar Sen1, Sanjay Mittal2, Gautam Biswas1
CMES-Computer Modeling in Engineering & Sciences, Vol.86, No.1, pp. 1-28, 2012, DOI:10.3970/cmes.2012.086.001
Abstract The steady flow around elliptic cylinders is investigated using a stabilized finite-element method. The Reynolds number, Re, is based on cylinder major
axis and free-stream speed. Results are presented for Re ≤ 40 and 0° ≤ α ≤ 90°, where α is angle of attack. Cylinder aspect ratios, AR considered are 0.2 (thin), 0.5, 0.8 (thick) and 1.0. Results for the laminar separation Reynolds number, Res available in the literature are only for thin cylinder and exhibit large scatter. Also, very limited information is available for separation angle. The present study attempts to provide this data. In addition, issues concerning… More >
Open Access
ARTICLE
H. Çerdik Yaslan1
CMES-Computer Modeling in Engineering & Sciences, Vol.86, No.1, pp. 29-38, 2012, DOI:10.3970/cmes.2012.086.029
Abstract This paper presents the approximate analytical solutions to the time fractional differential equations of elasticity for 3D quasicrystals with initial conditions. These equations are written in the form of a vector partial differential equation of the second order. The time fractional vector partial differential equations with initial conditions are solved by variational iteration method (VIM). The fractional derivatives are described in the Caputo sense. Numerical example shows that the proposed method is quite effective and convenient for solving kinds of time fractional system of partial differential equations. More >
Open Access
ARTICLE
Afet Golayoğlu Fatullayev1, Canan Köroğlu2
CMES-Computer Modeling in Engineering & Sciences, Vol.86, No.1, pp. 39-52, 2012, DOI:10.3970/cmes.2012.086.039
Abstract In this work we solve numerically a boundary value problem for second order fuzzy differential equations under generalized differentiability in the form y''(t) = p(t)y'(t) + q(t)y(t) + F(t) y(0) = γ, y(l) = λ where t ∈T = [0,l], p(t)≥0, q(t)≥0 are continuous functions on [0,l] and [γ]α = [γ_α,γ−α], [λ]α = [λ_α,λ¯α] are fuzzy numbers. There are four different solutions of the problem (0.1) when the fuzzy derivative is considered as generalization of the H-derivative. An algorithm is presented and the finite difference method is used for solving obtained problems. The applicability of presented… More >
Open Access
ARTICLE
Yixian Du1,2, De Chen1,3
CMES-Computer Modeling in Engineering & Sciences, Vol.86, No.1, pp. 53-70, 2012, DOI:10.3970/cmes.2012.086.053
Abstract This study proposes a new topology optimization method for continuum structures, which includes modified heuristic optimality criteria in conjunction with the SIMP scheme to suppress gray-scale elements occurred in topology optimization of continua through smoothed Heaviside function. In the process of numerical implementation, the gray scale elements are suppressed to approach the binary bounds of 0 or 1 by utilizing the proposed approach and the corresponding convergence criterion. Two typical numerical examples are used to demonstrate the effectiveness of the proposed method in suppressing the gray-scale elements with intermediate densities, as well as the efficiency of this method in the… More >