Tatyana Lyubimova^1,2,*, Yulia Garicheva², Andrey Ivantsov¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.11, pp. 2417-2429, 2024, DOI:10.32604/fdmp.2024.052391 - 28 October 2024

Abstract External vibrations are known to be one of the promising ways to control the behavior of multiphase systems. The computational modeling of the behavior of a gas bubble in a viscous liquid in a horizontal cylinder of square cross-section, which undergoes linearly polarized translational oscillations in weightless conditions, has been carried out. Under vibrations, the bubble moves towards the wall of the vessel with acceleration determined by the amplitudes and frequency of vibrations. Near the wall, at a distance of the order of the thickness of the viscous Stokes boundary layer, the effects of viscosity More >

Junhua Gong¹, Yujie Chen^2,*, Bo Yu², Bin Chen¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.29, No.4, pp. 1-2, 2024, DOI:10.32604/icces.2024.012531

Abstract Traditional interface reconstruction methods often rely on numerical approaches, which can be inefficient when dealing with large bubbles, requiring extensive computational resources. To address this issue, we propose a novel model based on convolutional neural networks aimed at rapidly and accurately predicting the equations governing circular bubbles. This model takes the volume fraction of the main-phase fluid surrounding each computational grid cell as input variables and is capable of precisely forecasting the coordinates and radii of bubbles. To further enhance model performance, we employ the Optuna hyperparameter optimizer to fine-tune the model's parameters. Upon training More >

Yang Cao^1,*, Jianshu Liu², Xuhui Meng¹

Frontiers in Heat and Mass Transfer, Vol.22, No.2, pp. 675-685, 2024, DOI:10.32604/fhmt.2024.051208 - 20 May 2024

Abstract Boiling heat transfer, as an efficient heat transfer approach, that can absorb a large amount of latent heat during the vaporization, is especially suitable for heat transfer occasions with high heat flux demands. Experimental studies show that the surface tension coefficient of pure water can be reduced sharply (up to 25%) when it is magnetized by a magnetic field applied externally. In this paper, magnetized water (MW) was used as the work fluid to conduct boiling heat transfer experiments, to explore the influence of magnetization on the boiling characteristics of pure water. The electromagnetic device… More >

Ayat N. Mahmood¹, Amer A. Abdulrahman¹, Laith S. Sabri^1,*, Abbas J. Sultan¹, Hasan Shakir Majdi², Muthanna H. Al-Dahhan³

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.2, pp. 239-256, 2024, DOI:10.32604/fdmp.2023.028015 - 14 December 2023

Abstract Hydrodynamics characterization in terms of flow regime behavior is a crucial task to enhance the design of bubble column reactors and scaling up related methodologies. This review presents recent studies on the typical flow regimes established in bubble columns. Some effort is also provided to introduce relevant definitions pertaining to this field, namely, that of “void fraction” and related (local, chordal, cross-sectional and volumetric) variants. Experimental studies involving different parameters that affect design and operating conditions are also discussed in detail. In the second part of the review, the attention is shifted to cases with More >

Meng Jia, Mingjun Pang^*

Frontiers in Heat and Mass Transfer, Vol.21, pp. 337-366, 2023, DOI:10.32604/fhmt.2023.044286 - 30 November 2023

Abstract The interphase mass, heat transfer efficiency, and flow resistance are strongly dependent on bubble size in gasliquid two-phase systems, so it is very important for engineering applications to effectively control bubble size. In this paper, the formation, growth, and detachment of single bubbles in Newtonian liquids based on capillary needles were studied in detail using a volume of fluid method. The authors investigated the effects of gas injection velocity, gravitational level, surface tension coefficient, needle radius, and liquid−phase properties (liquid viscosity and density) on the process of bubble generation, and the effects of the above… More >

Shaopeng Liu¹, Guowei Wang^2,3,*, Pengfei Liu¹, Dong Ye¹, Jian Song¹, Xing Liu¹, Yang Cheng^2,3

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.12, pp. 3045-3058, 2023, DOI:10.32604/fdmp.2023.029810 - 27 October 2023

Abstract Foam drainage is the flow of liquid through the interstitial spaces between bubbles driven by capillarity and gravity and resisted by viscous damping. The so-called foam drainage gas recovery technology is a technique traditionally used to mitigate the serious bottom-hole liquid loading in the middle and late stages of gas well production. In this context, determining the optimal concentration of the bubble drainage agent is generally crucial for the proper application of this method. In this study, a combination of indoor experiments and theoretical analysis have been used to determine the pressure drop related to… More >

Jianli Shao^1,2,*, Weidong Wei¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.26, No.4, pp. 1-1, 2023, DOI:10.32604/icces.2023.09101

Abstract This report mainly introduces our recent research on the shock-induced collapse, migration and coalescence of He bubbles in metal based on atomistic simulations. The He bubble will be compressed to permanent deformation with the finite plastic collapse of metal. Under strong shock, the He bubble can be breakdown by the nano-jet of the metal, but it returns to a reduced sphere in the molten metal after long-time evolution, driven by the He-Al interface energy. Besides, the shock-induced migration of He bubble is revealed, which can be divided into shock acceleration and the following inertial motion. More >

Dalia S. Makki¹, Hasan Sh. Majdi², Amer A. Abdulrahman¹, Abbas J. Sultan^1,3,*, Zahraa W. Hasan¹, Laith S. Sabri^1,3, Bashar J. Kadhim¹, Muthanna H. Al-Dahhan³

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.10, pp. 2613-2637, 2023, DOI:10.32604/fdmp.2023.028081 - 25 June 2023

Abstract Bubble and slurry bubble column reactors (BCRs/SBCRs) are used for various chemical, biochemical, and petrochemical applications. They have several operational and maintenance advantages, including excellent heat and mass transfer rates, simplicity, and low operating and maintenance cost. Typically, a catalyst is present in addition to biochemical processes where microorganisms are used to produce industrially valuable bio-products. Since most applications involve complicated gas-liquid, gas-liquid-solid, and exothermic processes, the BCR/SBCR must be equipped with heat-exchanging tubes to dissipate heat and control the reactor’s overall performance. In this review, past and very recent experimental and numerical investigations on More >

Ningbo Guo, Xianming Gao^*, Duanling Li, Jixing Zhang, Penghui Yin, Mengyi Hua

CMES-Computer Modeling in Engineering & Sciences, Vol.136, No.3, pp. 3061-3082, 2023, DOI:10.32604/cmes.2023.026657 - 09 March 2023

Abstract Computational fluid dynamics was used and a numerical simulation analysis of boiling heat transfer in microchannels with three depths and three cross-sectional profiles was conducted. The heat transfer coefficient and bubble generation process of three microchannel structures with a width of 80 μm and a depth of 40, 60, and 80 μm were compared during the boiling process, and the factors influencing bubble generation were studied. A visual test bench was built, and test substrates of different sizes were prepared using a micro-nano laser. During the test, the behavior characteristics of the bubbles on the More >

Muhammad Shahzeb Ali¹, Ali Alqahtani^2,*, Ansar Munir Shah¹, Adel Rajab², Mahmood Ul Hassan³, Asadullah Shaikh², Khairan Rajab², Basit Shahzad⁴

Computer Systems Science and Engineering, Vol.44, No.1, pp. 845-858, 2023, DOI:10.32604/csse.2023.025449 - 01 June 2022

Abstract Throughout the use of the small battery-operated sensor nodes encourage us to develop an energy-efficient routing protocol for wireless sensor networks (WSNs). The development of an energy-efficient routing protocol is a mainly adopted technique to enhance the lifetime of WSN. Many routing protocols are available, but the issue is still alive. Clustering is one of the most important techniques in the existing routing protocols. In the clustering-based model, the important thing is the selection of the cluster heads. In this paper, we have proposed a scheme that uses the bubble sort algorithm for cluster head More >