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 - 30 December 2021

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 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 - 16 December 2021

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. More >

Rongge Xiao^a,*, Dong Wang^a, Shuaishuai Jin^a, Hongping Yu^b, Bo Liu^a

Frontiers in Heat and Mass Transfer, Vol.16, pp. 1-9, 2021, DOI:10.5098/hmt.16.11

Abstract Based on the Viscous Kelvin-Helmholtz theory used by D. Barnea & Y. Taitel (1993), a two-fluid stratified flow model of gas-liquid two-phase flow is established. Using the mathematical derivation, the influence of various influence factors on the stability of liquid level structure is synthesized. Compared with the criteria of D Barnea & Y. Taitel (1993) and Taitel & Dukler(1976) , and the algorithm of flow pattern transition criterion of stratified flow is proposed. According to the data of multiphase flow experimental loop, the influence of liquid viscosity and the instantaneous volume flow rate change of More >

Ammar Hassan Soheel, Omar Mahmood Jumaah, Ahmed Mustaffa Saleem^*

Frontiers in Heat and Mass Transfer, Vol.17, pp. 1-7, 2021, DOI:10.5098/hmt.17.21

Abstract This paper presents a simulation and investigation of the heat transfer coefficient, pressure drop, and thermal conductivity of two - phase flow. The simulation was performed of mixtures (Al₂O₃ nanoparticles with R134a refrigerant). The size of nanoparticles (Al₂O₃) which is used in this study is 30 nm and volume concentrations are 0.015 and 0.03. The two – phase flowing through a horizontal circular microchannel of (diameter 100 µm, and length 20 mm) under constant heat flux (3000 W/m²) and constant wall temperature (330 K), also in this study used the inlet temperature at -20 oC and mass… 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 - 08 September 2021

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,… 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 - 05 July 2021

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 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 - 05 July 2021

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… 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 - 28 June 2021

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 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 - 04 June 2021

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 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 - 02 April 2021

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

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