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… More >

Y. Gan¹, Z. Chen^2,3, S. Montgomery-Smith⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.73, No.1, pp. 45-76, 2011, DOI:10.3970/cmes.2011.073.045

Abstract The material point method (MPM), which is an extension from computational fluid dynamics (CFD) to computational solid dynamics (CSD), is improved for the coupled CFD and CSD simulation of the zona failure response in piezo-assisted intracytoplasmic sperm injection (piezo-ICSI). To evaluate the stresses at any zona material point, a plane stress assumption is made in the local tangent plane of the membrane point, and a simple procedure is proposed to find the effective point connectivity for the orientation of the local tangent plane. With an iterative algorithm in each time step, the original MPM is More >

Mohsen Ghorbani¹, Hossein Eisazadeh²

FDMP-Fluid Dynamics & Materials Processing, Vol.6, No.2, pp. 153-164, 2010, DOI:10.3970/fdmp.2010.006.153

Abstract Polypyrrole/Poly(vinyl acetate) (PPy/PVAc) copolymer was prepared by the copolymerization of vinyl acetate and pyrrole using FeCl3and benzoylperoxide as an oxidant in the presence of various surfactants such as sodium dodecylbenzenesulfonate and poly(ethylene glycol) in the aqueous/non-aqueous media. The PPy/PVAc copolymer was characterized in terms of conductivity, morphology, chemical structure, particle size and yield. The results indicate that the morphology, particle size, yield and electrical conductivity of the products are dependent on the type of surfactant and the arrangement of monomer injection. The chemical structure of obtained product was determined by FTIR spectroscopy. By comparison FTIR More >

Mohsen Ghorbani¹, Hossein Eisazadeh²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.13, No.4, pp. 67-68, 2009, DOI:10.3970/icces.2009.013.067

Abstract Polypyrrole/Poly(vinyl acetate) (PPy/PVAc) copolymer was prepared by the copolymerization of vinyl acetate and pyrrole using FeCl3 and benzoylperoxide as an oxidant in the presence of various surfactants such as sodium dodecylbenzenesulfonate and poly (ethylene glycol) in the aqueous/non-aqueous media. The PPy/PVAc copolymer was characterized in terms of conductivity, morphology, chemical structure, particle size and yield. The results indicate that the morphology, particle size, yield and electrical conductivity of the products are dependent on the type of surfactant and the arrangement of monomer injection. The chemical structure of obtained product was determined by FTIR spectroscopy. By More >

Hun Jung¹, Jin Seok Kim¹, Jeong Soo Kim², Jeong Park³

The International Conference on Computational & Experimental Engineering and Sciences, Vol.11, No.4, pp. 125-126, 2009, DOI:10.3970/icces.2009.011.125

Abstract An injector plays an important role in the process of an efficient combustion in liquid-rocket engines (LRE) because it affects the evaporation rate of liquid fuel through spatial distribution and atomization of spray droplets. This paper is focused on the injection performance of a small LRE-Injector by employing the spray characteristic parameters made up of the velocity components, mean diameter, turbulence intensity, span (width of drop size distribution), number density, and volume flux of spray droplets. An experimental investigation is carried out with the aid of a dual-mode phase Doppler anemometry (DPDA) according to the… More >

Huamin Zhou¹, Hua Zhang, Dequn Li²

CMES-Computer Modeling in Engineering & Sciences, Vol.46, No.3, pp. 209-220, 2009, DOI:10.3970/cmes.2009.046.209

Abstract Gas-assisted injection molding is an innovative process to manufacture hollow polymeric products, in which gas penetration is the primary and key problem. An analytical solution of the gas penetration interface is presented, based on perturbation method. First, the governing equations and boundary conditions are transformed to be dimensionless, where Capillary number Ca is introduced. Then matching asymptotic expansion method is applied to solve these equations, by using Ca and as perturbation parameters to get the inner and outer solutions, respectively. By matching these two solutions, the analytical model of gas penetration is obtained. More >

H-L. Wang¹

Molecular & Cellular Biomechanics, Vol.3, No.4, pp. 145-146, 2006, DOI:10.32604/mcb.2006.003.145

Abstract This article has no abstract. More >

R. Mathur¹, S. G. Advani², B. K. Fink³

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.5, pp. 587-602, 2003, DOI:10.3970/cmes.2003.004.587

Abstract Real number-coded hybrid genetic algorithms for optimal design of resin injection locations for the resin transfer molding process are evaluated in this paper. Resin transfer molding (RTM) is widely used to manufacture composite parts with material and geometric complexities, especially in automotive and aerospace sectors. The sub-optimal location of the resin injection locations (gates) can leads to the formation of resin starved regions and require long mold fill times, thus affecting the part quality and increasing manufacturing costs. There is a need for automated design algorithms and software that can determine the best gate and… More >