Dong Zhou^1,*, Zhuoying Tan²

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.5, pp. 903-917, 2020, DOI:10.32604/fdmp.2020.010363

Abstract In this study, a two-dimensional approach is elaborated to study with the lattice Boltzmann method (LBM) the seepage of water in the pores of a soil. Firstly, the D2Q9 model is selected to account for the discrete velocity distribution of water flow. In particular, impermeability is considered as macroscopic boundary condition for the left and right domain sides, while the upper and lower boundaries are assumed to behave as pressure boundaries controlled by different densities. The micro-boundary conditions are implemented through the standard rebound strategy and a non-equilibrium extrapolation scheme. Matlab is used for the development of the related algorithm.… More >

Hao Sun¹, Timothy Eswothy¹, Kerlin P. Robert¹, Jiaoyan Li², L. G. Zhang¹, James D. Lee^1,*

Molecular & Cellular Biomechanics, Vol.16, Suppl.2, pp. 75-75, 2019, DOI:10.32604/mcb.2019.07090

Abstract Most biological phenomena commonly involve with mechanics. In this work, we proposed an innovative model that tumor is considered as a pyroelastic medium consisting of two parts: solid and fluid. The variation of solid part depends on whether the drug has been effectively delivered to the tumor site. We derived the governing equations of the tumor, in which large deformation is incorporated. Meanwhile, the finite element equations for coupled displacement field and pressure field are formulated. We proposed two sets of porosity and growth tensor. In both cases the continuum theory and FEM are accompanied by accurate numerical simulations. To… More >

Yi Xue^1,2,*, Faning Dang², Rongjian Li², Fei Liu³

CMES-Computer Modeling in Engineering & Sciences, Vol.115, No.3, pp. 345-358, 2018, DOI: 10.3970/cmes.2018.08052

Abstract Adsorption deformation significantly affects the seepage characteristics of coal. However, effect of sorption time on coal permeability and gas pressure has not been investigated systematically. In this study, the sorption experiment of coal samples is conducted to elaborate the importance of sorption equilibration time. Then a coupled coal deformation and gas flow model is established considering the sorption characteristic and permeability evolution. This coupled model is implemented through finite element method to analyze the effect of sorption time on coal permeability and gas pressure. The simulation results reveal that the gas pressure of the coal will change with the adsorption… More >

Antonio Greco*, Francesca Ferrari, Raffaella Striani, Carola Esposito Corcione

Journal of Renewable Materials, Vol.7, No.10, pp. 1023-1035, 2019, DOI:10.32604/jrm.2019.07778

Abstract This work is aimed at the development of new green composite materials through the incorporation of the solid organic waste (SOW) in a thermoplastic matrix. After being ground, the organic waste was exposed to a sterilization process, though an autoclave cycle, in order to obtain a complete removal of the bacterial activity. The SOW was found to have a high amount of water, about 65-70%, which made uneconomical its further treatment to reduce the water amount. Therefore, a water soluble polymer, poly (vinyl alcohol) (PVA) was chosen in order to produce SOW based blends. However, in order to reduce the… More >

Dan-Thuy Van-Pham^1,*, Minh Tri Nguyen¹, Chanh-Nghiem Nguyen², Thi Truc Duyen Le¹, Thi Yen Nhu Pham¹, Khai Thinh Nguyen², Yukihiro Nishikawa³, Qui Tran-Cong-Miyata³

Journal of Renewable Materials, Vol.6, No.6, pp. 662-670, 2018, DOI:10.7569/JRM.2018.634107

Abstract The mechanical properties of unidirectional natural fiber-reinforced composites are generally affected by several processing parameters during compression molding. This study investigates the effects of processing temperature, time, and pressure on the tensile and flexural properties of acrylonitrile butadiene styrene reinforced by banana fibers. X-ray CT imaging was employed to find the relationship between the mechanical properties and structure of the processed composite. Besides, the water absorption of composites was observed and the way in which the mechanical properties evolved after water absorption was analyzed. The tensile and flexural properties of the unidirectional banana fiber-reinforced composite were found to be inversely… More >

Dounia Bendahou^1,2, Abdelkader Bendahou¹, Bastien Seantier¹, Bénédicte Lebeau³, Yves Grohens^1,*, Hamid Kaddami^2,*

Journal of Renewable Materials, Vol.6, No.3, pp. 299-313, 2018, DOI:10.7569/JRM.2017.634185

Abstract Hybrid aerogels have been prepared by freeze-drying technique after mixing water dispersions of cellulose microfibers or cellulose nanofibers and silica (SiO2) of type SBA-15 (2D-hexagonal). The prepared composites were characterized by different analysis techniques such as SEM, hot-filament, DMA, etc. These composites are compared to those previously prepared using nanozeolites (NZs) as mineral charge. The morphology studied by SEM indicated that both systems have different structures, i.e., individual fibers for cellulose microfibers WP-based aerogels and films for nanofibrillated cellulose NFC-based ones.... These differences seem to be driven by the charge of the particles, their aspect ratio and concentrations. These hybrid… More >

Yi Xue^1,2,3

CMES-Computer Modeling in Engineering & Sciences, Vol.113, No.4, pp. 429-441, 2017, DOI:10.3970/cmes.2017.113.429

Abstract The lack of research on the effect of diffusion on methane extraction leads to low methane concentration and low utilization. The Comsol Multiphysics software is used to solve the numerical gas and solid coupled model which considers the diffusion of coal matrix, fracture seepage, permeability evolution and coal deformation. The simulation results reveal the effect of diffusion process on methane migration. The gas diffusion rate is relatively high in the initial stage. With the increase in time, the difference between coal fractures and coal matrix blocks becomes lower and the gas diffusion rate decreases gradually. The gas seepage rate decreases… More >

V. Sansalone^1,∗, V. Bousson², S. Naili¹, C. Bergot², F. Peyrin³, J.D. Laredo², G. Haïat¹

CMES-Computer Modeling in Engineering & Sciences, Vol.87, No.5, pp. 387-410, 2012, DOI:10.3970/cmes.2012.087.387

Abstract This paper investigates the effects of the heterogeneous distribution of the Haversian Porosity (HP) and Tissue Mineral Density (TMD) on the elastic coefficients of bone in the human femoral neck. A bone specimen from the inferior femoral neck was obtained from a patient undergoing standard hemiarthroplasty. The specimen was imaged using 3-D synchrotron micro-computed tomography (voxel size of 10.13 mm), leading to the determination of the anatomical distributions of HP and TMD. These experimental data were used to estimate the elastic coefficients of the bone using a three-step homogenization model based on continuum micromechanics: (i) At the tissue scale (characteristic… More >

A.B. Tatomir^1,2, A.Szymkiewicz³, H. Class¹, R. Helmig¹

CMES-Computer Modeling in Engineering & Sciences, Vol.77, No.2, pp. 81-112, 2011, DOI:10.3970/cmes.2011.077.081

Abstract We present a two phase flow conceptual model, the corresponding simulator (2pMINC) and a workflow for large-scale fractured reservoirs, based on a continuum fracture approach which uses the multiple interacting continua (MINC) method complemented with an improved upscaling technique. The complex transient behavior of the flow processes in fractured porous media is captured by subgridding the coarse blocks in nested volume elements which have effective properties calculated from the detailed representation of the fracture system. In this way, we keep a physically based approach, preserve the accuracy of the model, avoid the common use of empirically derived transfer functions and… More >

Xuebo Zhang^{1, 2, 3}, Zhiwei Jia^{1, 2, 3, *}

FDMP-Fluid Dynamics & Materials Processing, Vol.15, No.1, pp. 53-61, 2019, DOI:10.32604/fdmp.2019.04779

Abstract The influence of ground stress was quantitatively analyzed on coal seam gas pressure and gas content in this paper. Mining activities in coal mine can result in stress concentration in the coal (rock) body around the mining space, but porosity of the coal seam would not change too much. Therefore, gas pressure and gas content in the coal seam are slightly affected. Studies showed that the free gas was gradually transformed into adsorbed gas, and the gas adsorption volume was small, and then gas pressure increases roughly linearly when the porosity decreased because of stress influence. Additionaly, when porosity of… More >