Xian Zhou¹, Fei Wang², Ziyu Wang³, Yunfeng Xu^1,*

Energy Engineering, Vol.119, No.2, pp. 653-664, 2022, DOI:10.32604/ee.2022.019072

Abstract The reservoir is the networked rock skeleton of an oil and gas trap, as well as the generic term for the fluid contained within pore fractures and karst caves. Heterogeneity and a complex internal pore structure characterize the reservoir rock. By introducing the fractal permeability formula, this paper establishes a fractal mathematical model of oil-water two-phase flow in an oil reservoir with heterogeneity characteristics and numerically solves the mathematical model using the weighted least squares meshless method. Additionally, the method’s correctness is verified by comparison to the exact solution. The numerical results demonstrate that the fractal oil-water two-phase flow mathematical… More >

Ningbo Jing¹, Mingqiao Li¹, Lang Liu^2,*, Yutong Shen¹, Peijiao Yang¹, Xuebin Qin¹

CMES-Computer Modeling in Engineering & Sciences, Vol.131, No.1, pp. 465-476, 2022, DOI:10.32604/cmes.2022.018965

Abstract During mine filling, the caking in the pipeline and the waste rock in the filling slurry may cause serious safety accidents such as pipe blocking or explosion. Therefore, the visualization of the inner mine filling of the solid–liquid two-phase flow in the pipeline is important. This paper proposes a method based on capacitance tomography for the visualization of the solid–liquid distribution on the section of a filling pipe. A feedback network is used for electrical capacitance tomography reconstruction. This reconstruction method uses radial basis function neural network fitting to determine the relationship between the capacitance vector and medium distribution error.… More >

Xuebin Qin^1,*, Yutong Shen¹, Jiachen Hu¹, Mingqiao Li¹, Peijiao Yang¹, Chenchen Ji¹, Xinlong Zhu²

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.3, pp. 1699-1717, 2022, DOI:10.32604/cmes.2022.018234

Abstract Electrical capacitance tomography (ECT) has great application potential in multiphase process monitoring, and its visualization results are of great significance for studying the changes in two-phase flow in closed environments. In this paper, compressed sensing (CS) theory based on dictionary learning is introduced to the inverse problem of ECT, and the K-SVD algorithm is used to learn the overcomplete dictionary to establish a nonlinear mapping between observed capacitance and sparse space. Because the trained overcomplete dictionary has the property to match few features of interest in the reconstructed image of ECT, it is not necessary to rely on the sparsity… More >

Tiankui Guo^1,*, Zhilin Luo¹, Shanbo Mou², Ming Chen¹, Yuanzhi Gong³, Jianhua Qin⁴

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.2, pp. 431-447, 2022, DOI:10.32604/fdmp.2022.017861

Abstract Although the dynamics of proppant (small ceramic balls used to prevent opened fractures from closing on the release of pressure) have been the subject of several numerical studies over recent years, large-scale inclined fractures exist in unconventional reservoirs for which relevant information is still missing. In the present study, this problem is investigated numerically considering the influence of several relevant factors such as the fracture roughness, inclination, the proppant particle size, the injection rate and the fluid viscosity. The results show that a rough wall enables the proppant to travel farther and cover larger areas. The inclination angle has little… More >

Li Lei¹, Jun An¹, Fushun Liang¹, Cheng Cheng¹, Naixiang Zhou², Yanhong Ning³, Jingzhi Zhang^1,4,*

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.6, pp. 1037-1048, 2021, DOI:10.32604/fdmp.2021.016081

Abstract The flow patterns and the void fraction related to a gas-liquid two-phase flow in a small channel are experimentally studied. The test channel is a transparent quartz glass circular channel with an inner diameter of 6.68 mm. The working fluids are air and water and their superficial velocities range from 0.014 to 8.127 m/s and from 0.0238 to 0.556 m/s, respectively. The void fraction is determined using the flow pattern images captured by a high-speed camera, while quick closing valves are used for verification. Four flow patterns are analyzed in experiments: slug flow, bubbly flow, annular flow and stratified flow.… More >

Lihui Ma¹, Limin He^1,2,*, Xiaoming Luo^1,2, Xiangran Mi³

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.5, pp. 959-970, 2021, DOI:10.32604/fdmp.2021.016710

Abstract Dedicated experiments and numerical simulations have been conducted to investigate the splitting characteristics of a gas-liquid two phase flow at a T junction. The experiments were carried out for different gas-liquid velocities. The flow rates in the two branches were measured accurately to determine how the two considered phases distribute in the two outlets. The experimental results have shown that when the two outlet pressures are asymmetric, the two-phase flow always tends to flow into the outlet which has a lower pressure. As the inlet liquid velocity increases, however, the two-phase flow gradually tends to split evenly. Compared with the… More >

Peijian Zhou^1,2, Chaoshou Yan³, Lingfeng Shu⁴, Hao Wang², Jiegang Mou^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.5, pp. 871-886, 2021, DOI:10.32604/fdmp.2021.012250

Abstract Single-channel sewage pumps are generally used to transport solid-liquid two-phase media consisting of a fluid and solid particles due to the good non-clogging property of such devices. However, the non-axisymmetric structure of the impeller of this type of pumps generally induces flow asymmetry, oscillatory outflow during operations, and hydraulic imbalance. In severe cases, these effects can jeopardize the safety and stability of the overall pump. In the present study, such a problem is investigated in the framework of a Mixture multiphase flow method coupled with a RNG turbulence model used to determine the structure of the flow field and the… More >

Yunxing Zhang, Shan Ma, Kangping Liao, Wenyang Duan^*

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.1, pp. 43-64, 2021, DOI:10.32604/cmes.2021.014847

Abstract In this study, a numerical model for simulating two-phase flow is developed. The Cartesian grid with Adaptive Mesh Refinement (AMR) is adopted to reduce the computational cost. An explicit projection method is used for the time integration and the Finite Difference Method (FDM) is applied on a staggered grid for the discretization of spatial derivatives. The Volume of Fluid (VOF) method with Piecewise-Linear Interface Calculation (PLIC) is extended to the AMR grid to capture the gas-water interface accurately. A coarse-fine interface treatment method is developed to preserve the flux conservation at the interfaces. Several two-dimensional (2D) and three-dimensional (3D) benchmark… More >

Samer Alabed^*, Issam Maaz, Mohammad Al-Rabayah

CMC-Computers, Materials & Continua, Vol.69, No.1, pp. 539-553, 2021, DOI:10.32604/cmc.2021.018061

Abstract In this article, we introduce a new bi-directional dual-relay selection strategy with its bit error rate (BER) performance analysis. During the first step of the proposed strategy, two relays out of a set of N relay-nodes are selected in a way to optimize the system performance in terms of BER, based on the suggested algorithm which checks if the selected relays using the max-min criterion are the best ones. In the second step, the chosen relay-nodes perform an orthogonal space-time coding scheme using the two-phase relaying protocol to establish a bi-directional communication between the communicating terminals, leading to a significant… More >

Chenguang Guo^1,2,*, Yu Sun^1,2, Qiang Li¹, Haitao Yue¹, Chuang Wang¹

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.2, pp. 349-370, 2021, DOI:10.32604/fdmp.2021.013535

Abstract

To improve the agglomeration of powder in a coaxial powder feeding nozzle used in the frame of a laser energy deposition technique, the influence of several parameters must be carefully assessed. In the present study the problem is addressed by means of numerical simulations based on a DEM-CFD (Discrete Element Method and Discrete Element Method) coupled model. The influence of the powder flow concentration, powder flow focal length and the amount of powder at the nozzle outlet on the rate of convergence of the powder flow is considered. The role played by the nozzle outlet width, the angle between the… More >