G Devaraj¹, Shashi Narayan¹, Debasish Roy^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.102, No.1, pp. 1-54, 2014, DOI:10.3970/cmes.2014.102.001

Abstract This work sets forth a 'hybrid' discretization scheme utilizing bivariate simplex splines as kernels in a polynomial reproducing scheme constructed over a conventional Finite Element Method (FEM)-like domain discretization based on Delaunay triangulation. Careful construction of the simplex spline knotset ensures the success of the polynomial reproduction procedure at all points in the domain of interest, a significant advancement over its precursor, the DMS-FEM. The shape functions in the proposed method inherit the global continuity (C^p-1) and local supports of the simplex splines of degree p. In the proposed scheme, the triangles comprising the domain discretization also serve as background… More >

Sunilkumar N¹, D Roy^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.66, No.3, pp. 249-284, 2010, DOI:10.3970/cmes.2010.066.249

Abstract We propose a family of 3D versions of a smooth finite element method (Sunilkumar and Roy 2010), wherein the globally smooth shape functions are derivable through the condition of polynomial reproduction with the tetrahedral B-splines (DMS-splines) or tensor-product forms of triangular B-splines and 1D NURBS bases acting as the kernel functions. While the domain decomposition is accomplished through tetrahedral or triangular prism elements, an additional requirement here is an appropriate generation of knotclouds around the element vertices or corners. The possibility of sensitive dependence of numerical solutions to the placements of knotclouds is largely arrested by enforcing the condition of… More >

Sunilkumar N¹, D Roy^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.65, No.2, pp. 107-154, 2010, DOI:10.3970/cmes.2010.065.107

Abstract The element-based piecewise smooth functional approximation in the conventional finite element method (FEM) results in discontinuous first and higher order derivatives across element boundaries. Despite the significant advantages of the FEM in modelling complicated geometries, a motivation in developing mesh-free methods has been the ease with which higher order globally smooth shape functions can be derived via the reproduction of polynomials. There is thus a case for combining these advantages in a so-called hybrid scheme or a 'smooth FEM' that, whilst retaining the popular mesh-based discretization, obtains shape functions with uniform C^p(p ≥ 1) continuity. One such recent attempt, a… More >

Shunde Yin¹, Leo Rothenburg¹, Maurice B. Dusseault¹

CMES-Computer Modeling in Engineering & Sciences, Vol.19, No.2, pp. 111-120, 2007, DOI:10.3970/cmes.2007.019.111

Abstract Subsidence problem is of great importance in petroleum engineering and environmental engineering. In this paper, we firstly apply a hybrid Displacement Discontinuity-FEM modeling to this classic problem: the evaluation of subsidence over a compacting oil reservoir. We use displacement discontinuity method to account for the reservoir surrounding area, and finite element methods in the fully coupled simulation of the reservoir itself. This approach greatly reduces the number of degrees of freedom compared to an analyzing fully coupled problem using only a finite element or finite difference discretization. More >

Jin Pang^1,*, Di Luo², Haohong Gao³, Jie Liang⁴, Yuanyuan Huang¹, Qi Liu³

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.1, pp. 39-51, 2019, DOI:10.32604/fdmp.2019.06136

Abstract High-pressure deep shale gas reservoirs are usually highly stress-sensitive. When the reasonable production mode of shale gas well is built, the impact of strong stress sensitivity should be fully considered. First, this study calculated the relationship between permeability and formation pressure under different elastic modulus based on the shale lithology of Long Ma Xi formation in Sichuan Basin by testing and analysing the mechanical parameters of the rock. According to numerical simulation result, when the elastic modulus exceeds 14.0 GPa, the stress sensitivity of the matrix will slight affect the cumulative gas production of shale gas. Second, the changing relation… More >

Munther Issa K,ah¹, Jean-Luc Meunier²

FDMP-Fluid Dynamics & Materials Processing, Vol.5, No.2, pp. 123-136, 2009, DOI:10.3970/fdmp.2009.005.123

Abstract Multi walled carbon nanotubes (MWCNTs) were synthesized on different graphite types covered with thin layer of nickel catalyst by catalytic chemical vapour deposition using acetylene as hydrocarbon source. The produced carbon nanotubes were investigated by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and transmission electron microscopy (TEM). The shape, quantity and diameter of the MWCNTs are shown to be affected by the type of the graphite substrate, the growth temperature and the hydrocarbon source flow rate. The diameters of the produced MWCNTs were ranged between 43 and 80 nm for pyrolytic (PYROID) and polycrystalline (AXF-5Q) graphite, respectively when the… More >

Munther Issa K,ah¹, Jean-Luc Meunier²

FDMP-Fluid Dynamics & Materials Processing, Vol.4, No.4, pp. 231-236, 2008, DOI:10.3970/fdmp.2008.004.231

Abstract Multi-walled carbon nanotubes (MWCNTs) have been produced by chemical vapor deposition using acetylene as a hydrocarbon source at 700 \textdegree C. The Monel substrates coated with MWCNTs can be used later as cathodes in the Physical Vapor Deposition (PVD) systems to produce CNTs embedded in diamond-like carbon (DLC) film. This new method of generating MWCNTs on Monel substrates without using any catalyst is very simple and uses very little power compared to other CNTs generating techniques. Embedded CNTs in a crystalline carbon coat was observed on mirror-like polished Monel substrates at 700 \textdegree C but not on the rough Monel… More >

He Shi^1,2,3,4, Wenli Shang^1,2,3,4,*, Chunyu Chen^1,2,3,4, Jianming Zhao^1,2,3,4, Long Yin^{1, 2, 3, 4}

CMC-Computers, Materials & Continua, Vol.60, No.2, pp. 645-658, 2019, DOI:10.32604/cmc.2019.05648

Abstract In order to solve the problem of locating and protecting key processes and detecting outliers efficiently in complex industrial processes. An anomaly detection system which is based on the two-layer model fusion frame is designed in this paper. The key process is located by using the random forest model firstly, then the process data feature selection, dimension reduction and noise reduction are processed. Finally, the validity of the model is verified by simulation experiments. It is shown that this method can effectively reduce the prediction accuracy variance and improve the generalization ability of the traditional anomaly detection model from the… More >

Kabir Fardad¹, Bahman Najafi¹, Sina Faizollahzadeh Ardabili¹, Amir Mosavi^2,3, Shahaboddin Shamshirband,^4,5,*, Timon Rabczuk²

CMC-Computers, Materials & Continua, Vol.55, No.3, pp. 381-392, 2018, DOI: 10.3970/cmc.2018.01803

Abstract Glycyrrhiza glabra, Mint, Cuminum cyminum, Lavender and Arctium medicinal are considered as edible plants with therapeutic properties and as medicinal plants in Iran. After extraction process of medicinal plants, residual wastes are not suitable for animal feed and are considered as waste and as an environmental threat. At present there is no proper management of waste of these plants and they are burned or buried. The present study discusses the possibility of biogas production from Glycyrrhiza Glabra Waste (GGW), Mentha Waste (MW), Cuminum Cyminum Waste (CCW), Lavender Waste (LW) and Arctium Waste (AW). 250 g of these plants with TS… More >