K. Kakuda¹, K. Tochikubo¹, J. Toyotani¹

CMES-Computer Modeling in Engineering & Sciences, Vol.95, No.5, pp. 351-367, 2013, DOI:10.3970/cmes.2013.095.351

Abstract The application of a CPU/GPU-based particle method to dam-breaking incompressible viscous fluid flow problems is presented. The particle approach is based on the MPS (Moving Particle Semi-implicit) scheme using logarithmic weighting function to stabilize the spurious oscillatory solutions for solving the Poisson equation with respect to the pressure fields by using GPU-based SCG (Scaled Conjugate Gradient) method. The physics-based computer graphics for the results of three-dimensional simulation consist of the POV-Ray (Persistence of Vision Raytracer) rendering using marching cubes algorithm as polygonization. Numerical results demonstrate the workability and the validity of the present approach through More >

L. Sun¹, G. Yang², Q. Zhang³

CMES-Computer Modeling in Engineering & Sciences, Vol.95, No.3, pp. 235-258, 2013, DOI:10.3970/cmes.2013.095.234

Abstract We propose numerical integration rules for meshless local Petrov- Galerkin methods (MLPG) employed to solve elliptic partial different equations (PDE) with Neumann boundary conditions. The integration rules are required to satisfy an integration constraint condition of Green’s formula type (GIC). GIC was first developed in [Babuska, Banerjee, Osborn, and Zhang (2009)] for Galerkin meshless method, and we will show in this paper that it has better features for MLPG due to flexibility of MLPG in choosing different trial and test function spaces. A general constructive algorithm is presented to design the integration rules satisfying GIC. More >

Haitao Wang^1,2, Zhenhan Yao³

CMES-Computer Modeling in Engineering & Sciences, Vol.94, No.6, pp. 507-527, 2013, DOI:10.3970/cmes.2013.094.507

Abstract This paper presents the use of a three-dimensional time domain boundary element method (BEM) in conjunction with adaptive cross approximation method (ACA) for dynamic analyses of the HTR-PM nuclear island foundation. The advantage of this approach is that only foundation of the HTR-PM nuclear island and limited surfaces of the supporting half-space soil medium are modeled and analyzed in a direct time stepping scheme. In addition, the ACA can compress the BEM coefficient matrices at each time step efficiently, therefore allowing larger models to be analyzed compared with conventional BEMs. In order to discretize the More >

K. Kakuda¹, T. Nagashima¹, Y. Hayashi¹, S. Obara¹, J. Toyotani¹, S. Miura², N. Katsurada³, S. Higuchi³, S. Matsuda³

CMES-Computer Modeling in Engineering & Sciences, Vol.93, No.5, pp. 363-376, 2013, DOI:10.3970/cmes.2013.093.363

Abstract The application of a GPU-based particle method to three-dimensional incompressible viscous fluid flow problems is presented. The particle approach is based on the MPS (Moving Particle Semi-implicit) scheme using logarithmic weighting function to stabilize the spurious oscillatory solutions for solving the Poisson equation with respect to the pressure fields by using GPU-based SCG (Scaled Conjugate Gradient) method. Numerical results demonstrate the workability and the validity of the present approach through the dam-breaking flow problem and flow behavior in a liquid ring pump with rotating impeller blades. More >

Smitha Gopinath¹, C.K. Madheswaran¹, A. Rama Ch,ra Murthy¹, Nagesh. R. Iyer², Barkavi.T³

CMES-Computer Modeling in Engineering & Sciences, Vol.92, No.2, pp. 151-172, 2013, DOI:10.3970/cmes.2013.092.151

Abstract This paper presents the details of experimental and numerical investigations performed on fabric reinforced concrete (FABcrete) panels under impact loading. Experimental investigations have been carried out using drop weight impact on a square FABcrete panel to study the damage, failure mode and acceleration. The drop weight of 20 kg is used for the study and drop heights have been varied as 100mm, 200mm and 300mm. Numerical simulation of the drop weight impact tests on FABcrete panels have been carried out and observed that there is a good correlation between experimental and numerical predictions. It is More >

N Pimprikar¹, J Teresa², D Roy^1,3, R M Vasu⁴, K Rajan⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.92, No.1, pp. 33-61, 2013, DOI:10.3970/cmes.2013.092.033

Abstract Nearly pollution-free solutions of the Helmholtz equation for k-values corresponding to visible light are demonstrated and verified through experimentally measured forward scattered intensity from an optical fiber. Numerically accurate solutions are, in particular, obtained through a novel reformulation of the H1 optimal Petrov-Galerkin weak form of the Helmholtz equation. Specifically, within a globally smooth polynomial reproducing framework, the compact and smooth test functions are so designed that their normal derivatives are zero everywhere on the local boundaries of their compact supports. This circumvents the need for a priori knowledge of the true solution on the More >

Zonglu Guo¹, Deli Gao¹

CMES-Computer Modeling in Engineering & Sciences, Vol.90, No.1, pp. 65-76, 2013, DOI:10.3970/cmes.2013.090.065

Abstract The modeling of the bottomhole assembly (BHA) is an essential problem in directional drilling. Some basic equations for predicting the performance of the BHA are presented in this paper. These equations take into account the effects of the axial displacement. The method of weighted residuals and the Newton-Raphson iterations are used to compute the nonlinear effects of the deformation of the BHA. A computer program is developed for the analysis of the BHA in order to quantitatively predict the performance of the BHA in directional drilling. In addition, a case study is presented to evaluate More >

Ahmed Mahmoudi^1,2, Imen Mejri¹, Mohamed Ammar Abbassi¹, Ahmed Omri¹

FDMP-Fluid Dynamics & Materials Processing, Vol.9, No.4, pp. 353-388, 2013, DOI:10.3970/fdmp.2013.009.353

Abstract A double-population Lattice Boltzmann Method (LBM) is applied to solve the steady-state laminar natural convective heat-transfer problem in a triangular cavity filled with air (Pr = 0.71). Two different boundary conditions are implemented for the vertical and inclined boundaries: Case I) adiabatic vertical wall and inclined isothermal wall, Case II) isothermal vertical wall and adiabatic inclined wall. The bottom wall is assumed to be at a constant temperature (isothermal) for both cases. The buoyancy effect is modeled in the framework of the well-known Boussinesq approximation. The velocity and temperature fields are determined by a D2Q9 More >

Arnon Blum¹, Snait Tamir², David Hazzan³, Oxana Podvitzky¹, Rizak Sirchan¹, Lital Keinan-Boker⁴, Rotem Shelly Ben-Shushan², Nava Blum¹, Laylee Shaich Suliman⁵, Nissim Geron⁶

European Cytokine Network, Vol.23, No.4, pp. 154-157, 2012, DOI:10.1684/ecn.2012.0318

Abstract Studies have shown that mortality was reduced by 31.6% in patients that underwent bariatric surgery compared with the non-operative control group. However, in most surgical series the majority of patients were women, and men had higher post-operative mortality rates and a higher postoperative morbidity, regardless of weight. Our primary end point was to study gender effects on vascular inflammation following bariatric surgery for weight loss. Methods. A prospective study evaluated vascular inflammation in obese patients before and three months after bariatric surgery. Markers of vascular inflammation were measured - before surgery and three months afterwards.Results.One… More >

Prodromos Philippou, David Payne, Francis Keeley

Canadian Journal of Urology, Vol.19, No.1, pp. 6118-6120, 2012

Abstract A “corkscrew deformity” of the proximal ureter is a rare congenital anomaly that typically lacks any postnatal clinical significance. The rarity of this entity, however, has not allowed the clarification of its natural history and the ideal approach to its management.
We herein present a case of a 27-year-old female patient who presented with right flank pain and significant hydronephrosis. On retrograde ureterography, a typical spiral configuration of the proximal ureter was noted. The patient underwent successful reconstruction by laparoscopic transperitoneal dismembered pyeloplasty. We report the first use of laparoscopic reconstruction for the management of More >