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 >

Yanbin Wang^1,2, Deli Gao¹, Jun Fang¹

CMC-Computers, Materials & Continua, Vol.48, No.1, pp. 25-42, 2015, DOI:10.3970/cmc.2015.048.025

Abstract In this paper, the buckling and collapse analysis of offshore pipeline under combined tension, bending moment, and external pressure has been presented with theoretical analysis and FE (finite element) simulation method respectively. Based on the model initially proposed by Kyriakides, a 2-D theoretical model has been further developed. To verify the correctness and accuracy of the model proposed in this paper, numerical simulations have been conducted with 3-D FE model using ABAQUS software. Good consistency has been shown between the calculation results which validate the availability of the theoretical analysis. On this basis, the influence More >

S. Hamimid^1,2, M. Guellal¹

FDMP-Fluid Dynamics & Materials Processing, Vol.10, No.3, pp. 377-393, 2014, DOI:10.3970/fdmp.2014.010.377

Abstract Combined laminar natural convection and surface radiation in a differentially heated square cavity has been investigated by a finite volume method through the concepts of staggered grid and SIMPLER approach. A power scheme has been also used in approximating advection–diffusion terms, determining the view factors by means of analytical expressions. The effect of emissivity on temperature and velocity profiles within the enclosure has been analyzed. In addition, results for local and average convective and radiative Nusselt numbers are presented and discussed for various conditions. More >

Ryan S. Hsi¹, Christopher J. Welty¹, Mathew D. Sorensen¹, Aashiyana F. Koreishi², Hunter Wessells¹

Canadian Journal of Urology, Vol.20, No.1, pp. 6646-6648, 2013

Abstract We report the first known case of concurrent partial cystectomy and cesarean delivery in a pregnant female with bladder pheochromocytoma. A 28-year-old G4P2 female presented at 28 weeks gestation with labile blood pressures requiring three antihypertensive medications. Urinary catecholamines were elevated, and a subsequent MRI showed a 2.6 cm x 3.2 cm bladder wall mass. She underwent combined cesarian section and partial cystectomy at 37 weeks. Fluid resuscitation and vasopressors were required in the immediate postoperative period. While bladder pheochromocytoma with pregnancy is a rare occurrence, concurrent delivery and removal of the bladder tumor can More >

Bingfei Liu¹, Guansuo Dui^2,3, Lijun Xue², Benming Xie¹

CMES-Computer Modeling in Engineering & Sciences, Vol.94, No.3, pp. 239-260, 2013, DOI:10.32604/cmes.2013.094.239

Abstract Analytical solutions are derived for the macroscopic behaviors of a Shape Memory Alloy (SMA) thick-walled cylinder subjected to internal pressure and radial temperature gradient. The Tresca transformation criterion and linear hardening are used. Equations are given for the radial and circumferential stresses, transformation strains and martensite volume fractions at both the elastic step and the transformation step. Numerical results are presented and in good agreement with the finite element simulations. More >

Gintautas Miliauskas^*, Stasys Sinkunas, Kristina Norvaisiene, Kestutis Sinkunas

Frontiers in Heat and Mass Transfer, Vol.3, No.2, pp. 1-6, 2012, DOI:10.5098/hmt.v3.2.3006

Abstract Water droplet evaporation process is numerically modelled under various heat and mass transfer conditions. Regularities of heat transfer process interaction are examined. Modelling in this work was performed using the combined analytical – numerical method to investigate heat and mass transfer in the two-phase droplets-gas flow system. The influence of forced liquid circulation on the thermal state of droplets is taken into account by the effective coefficient of thermal conductivity. Calculating the rate of droplet evaporation and the intensity of convective heating, the influence of the Stefan’s hydrodynamic flow is taken into account. Balancing energy More >

Yunpeng Ren, J. K. Chen^*, Yuwen Zhang

Frontiers in Heat and Mass Transfer, Vol.3, No.2, pp. 1-7, 2012, DOI:10.5098/hmt.v3.2.3001

Abstract Heat transfer in a copper film irradiated by a femtosecond (fs) laser pulse train and by an integrated dual laser beam of a nanosecond pulse with a fspulse train was studied using the semi-classical two-temperature model. The critical point model with three Lorentzian terms was employed to characterize transient optical properties for the laser energy deposition. The effects of pulse number and separation time on the thermal response were investigated. The results showed that with the same total energy in a fs-pulse train, more pulses for shorter separation time, e.g., 1 ps, and fewer pulses More >

O. Baysal¹, G. Tanoglu²

CMES-Computer Modeling in Engineering & Sciences, Vol.84, No.1, pp. 27-40, 2012, DOI:10.3970/cmes.2012.084.027

Abstract In this work, an operator splitting method is proposed in order to obtain a stable numerical solution for transport equation with non-linear reaction term. We split the transport equation into a reaction part and an advection diffusion part. The former one which becomes a nonlinear ordinary differential equation can be approximated by the simple higher order integrator or solved exactly. The later one is approximated by the Streamline-Upwind Petrov-Galerkin (SUPG) method combined with the generalized Euler time integration (θ-method). Numerical results that illustrate the good performance of this method are reported. More >

Li Shan, Ning Cui, Ming Cheng, Kaixin Liu

CMES-Computer Modeling in Engineering & Sciences, Vol.83, No.4, pp. 353-384, 2012, DOI:10.3970/cmes.2012.083.353

Abstract In the present paper, a combined scheme of discrete element method (DEM) and meshless method for numerical simulation of impact problems is proposed. Based on the basic principle of continuum mechanics, an axisymmetric DEM framework is established for modeling the elastoplastic behavior of solid materials. Failure criteria are introduced to model the transformation from a continuum to a discontinuum. The friction force between contact elements is also considered after the failure appears. So our scheme can calculate not only the behavior of continuum and discontinuum, but also the transformation process from a continuum to a More >

Li Shan, Ming Cheng, Kaixin Liu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.3, pp. 87-88, 2011, DOI:10.3970/icces.2011.019.087

Abstract In the present paper, a combined scheme of discrete element method (DEM) and meshless method for numerical simulation of impact problems is proposed. Based on the basic principle of continuum mechanics, an axisymmetric DEM framework is estabilished for modeling the elastoplastic behavior of solid materials. A failure criterion is introduced to model the transformation from a continuum to a discontinuum. The friction force between contact elements is also considered after the failure appears. So our scheme can calculate not only the behavior of continuum and discontinuum, but also the transformation process from continuum to discontinuum. More >