Article
Engineering, Chemical
Arash Ghafouri, Ashkan Ghafouri, Abbas Kosarineia, Alireza Daneh-Dezfuli
Summary: In this experimental study, the generation of annular flow pattern in a countercurrent two-phase flow was explored using image recording and processing methods. The liquid film thickness and interfacial friction factor were determined as correlation functions of various parameters, and their sensitivity to changes in gas phase velocity and liquid phase Reynolds number was analyzed.
JOURNAL OF THE TAIWAN INSTITUTE OF CHEMICAL ENGINEERS
(2023)
Article
Mechanics
Ayelet Goldstein, Ofer Eyal, Amos Ullmann, Neima Brauner
Summary: Exact solutions for laminar stratified two-phase flows in inclined pipes were used to explore the wall and interfacial shear stresses, resulting in closed-form analytical expressions for the average interfacial shear stress. The limiting behavior of the local shear stresses at the triple-point (TP) region was determined by residue calculus.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2021)
Article
Energy & Fuels
Wujie Wang, Guomin Cui, Yaoqi Wei, Jie Pan
Summary: A new model for calculating gas-liquid distribution in inclined gas wells was developed based on the principle of minimum energy, taking into account the influence of wettability and surface tension on interface shape, as well as factors like inclination angle, pipe diameter, and liquid holdup. The critical liquid-carrying velocity and pressure gradient showed low relative errors and misclassification rate in field trials, indicating the model's effectiveness in assessing liquid loading in inclined gas wells.
PETROLEUM EXPLORATION AND DEVELOPMENT
(2021)
Article
Nuclear Science & Technology
Pouya Ranjbari, Mohammad Emamzadeh
Summary: The optimal design of two-phase flow pipes depends on various variables such as pressure drop and liquid hold-up. Numerical simulation of pipes can estimate these parameters, but it strongly depends on phase frictions. A semi-empirical friction factor model is proposed in this study by modifying an existing model in the literature for stratified two-phase flows. Experimental data from various laboratories are used for validation and the predicted velocity profiles and shear stresses are in better agreement with the experimental data compared to previous models.
NUCLEAR ENGINEERING AND DESIGN
(2023)
Article
Mechanics
H. M. Aravind, Thomas Dubos, Manikandan Mathur
Summary: This study investigates the stability of two-dimensional Kelvin-Helmholtz vortices using numerical simulations. The results show that different types of instabilities occur at the core and the edge of the vortices, and stratification strongly influences the instability at the vortex edge. The dependence of the dominant instability characteristics on the Richardson number is systematically studied. The local stability approach is able to predict the orientation of flow structures resulting from different instabilities, consistent with previous three-dimensional numerical simulations.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Thermodynamics
Zhao Zhang, Jie Liu, Ruiquan Liao, Fushan Cheng
Summary: Liquid unloading by vortex tool is an important application of swirling flow pneumatic conveying. This study experimentally investigated the gas-liquid flow patterns and pressure drop inside a vortex tool inserted tube under liquid loading conditions. The results revealed three distinct swirling flow patterns downstream of the vortex tool, and indicated that the helix angle of the corkscrew deflector has a significant effect on the pressure drop. New friction factor correlations were established for both positive and negative friction regions in the cases of the tube with and without vortex tool.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2023)
Article
Thermodynamics
Mrinmoy Dhar, Subhabrata Ray, Gargi Das, Prasanta Kumar Das
Summary: This paper presents an experimental approach to investigate the role of planar hydraulic jump in termination of stratified gas-liquid flow in a narrow rectangular conduit. The study found that when the Froude number of the incoming liquid is greater than unity, stratified flow is terminated via the formation of a natural planar jump. The results show that undular jump results in slugging during co-current flow, while oscillatory jump induces flooding in countercurrent flow. The experimental results also confirm the correlation between the superficial gas and liquid velocities and the proposed criteria.
EXPERIMENTAL THERMAL AND FLUID SCIENCE
(2022)
Article
Engineering, Chemical
Lusheng Zhai, Bo Xu, Haiyan Xia, Ningde Jin
Summary: This study aims to develop the ultrasonic Doppler method for simultaneous measurement of velocity profile and liquid film thickness in intermittent horizontal gas-liquid two-phase flows. The results demonstrate that the Doppler system provides more accurate measurements of film thickness and reveals the effect of gas distribution on film thickness.
CHINESE JOURNAL OF CHEMICAL ENGINEERING
(2023)
Article
Mechanics
Joao N. E. Carneiro, Anis A. Ayati
Summary: This study analyzes interfacial waves in turbulent stratified air-water pipe flow. Conductance probes are used for interface elevation measurements. The frequency spectra and wave structure are assessed through the analysis of power spectral density (PSD). The influence of gas and liquid superficial velocities is considered. Dominant frequencies of approximately 7-8 and 3-4 Hz are observed in the wave growth and saturation regimes, respectively. The analysis also shows a direct relation between the dominant frequencies and the mean liquid depth.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2023)
Article
Engineering, Chemical
Jianhong Kang, Xinyu Zhang, Di Zhang, Yingke Liu
Summary: This study investigates the behaviors of gas-liquid two-phase flow in a horizontal pipe under the transition from laminar flow to turbulence at low gas flow rates. Experimental and theoretical analyses were conducted to obtain variations of frictional pressure drop gradient, critical Reynolds number, and composite correlations between friction factor and Reynolds number. The results show that the influence of gas flow rates on pressure drop is more significant for higher liquid flow rates.
CHEMICAL ENGINEERING SCIENCE
(2021)
Article
Engineering, Chemical
Shihui Sun, Jiahao Liu, Wan Zhang, Tinglong Yi
Summary: In this study, we numerically investigated the velocity distribution and phase distribution of a gas-liquid flow in coiled tubing (CT). The results showed that the gas and liquid velocities decrease first and then rise along the axial direction due to the effect of gravity. The gas-liquid slip velocity ratio is always greater than 1 due to the difference in gas and liquid viscosity. The liquid velocity exhibits a D-shaped step distribution at different cross-sections of the spiral tubing. The research results are important for understanding the complex flow behavior of gas-liquid two-phase flow in CT.
Article
Mechanics
S. F. Lewin, C. P. Caulfield
Summary: Motivated by the variation of local shear produced by internal waves in the ocean, this study investigates the effect of a time-dependent shear forcing on the evolution and mixing of turbulence produced by Kelvin-Helmholtz instability (KHI) through direct numerical simulations. The results demonstrate that turbulence produced by KHI with a decelerating shear mixes in a distinctly different way from the flow with constant background shear, with characteristics more in common with convectively driven flows.
JOURNAL OF FLUID MECHANICS
(2022)
Article
Engineering, Marine
Yuan Xue, Linjing Yue, Kang Xiao, Yuxing Li, Cuiwei Liu
Summary: This study investigates the propagation process of leakage acoustic waves in gas-liquid stratified flow through simulation and experimental verification. The results show that leakage acoustic waves propagate as a single plane wave in this flow pattern and the propagation process is nearly adiabatic. The study provides important insights for selecting the proper sound speed calculation model and improving the accuracy of leakage detection in gas-liquid stratified flow pipelines.
Article
Engineering, Chemical
Lin-tong Hou, Meng Yang, Li-song Wang, Shuo Liu, Jing-yu Xu
Summary: In this study, the authors investigated the three-dimensional interfacial characteristics of gas-liquid stratified flow in horizontal and slightly inclined pipes with a diameter of 100 mm. They observed a nonflat phenomenon in the gas-liquid stratified flow interface, exhibited as concave or convex shapes. The liquid holdup decreased with increasing inclination angle in the downward stratified flow, and the interface exhibited regular fluctuations in the flow direction. Based on experimental phenomena, the authors proposed a model to predict the degree of interface bending and critical conditions for gas-liquid stratified flow, which was validated to perform satisfactorily in comparison with experimental results. The proposed model allows effective prediction of interfacial information in the pipe cross section and flow direction.
CHEMICAL ENGINEERING SCIENCE
(2023)
Article
Engineering, Mechanical
Kexi Liao, Yuhan Liu, Guoxi He, Min Qin, Liang Wang, Jihui Leng, Xinhui Jiang
Summary: Shale gas reserves are abundant and widely distributed, holding immense development potential as a green and clean energy source. However, the transmission of shale gas often involves the presence of liquids, resulting in liquid-carrying gas flow and accumulation of liquid in low-lying areas. This leads to accelerated pipeline corrosion and perforation, posing risks to pipeline safety and causing significant economic losses. In this study, a transient model of liquid-carrying gas flow was established using computational fluid dynamics (CFD) to investigate the flow characteristics of liquid-carrying gas in up-dip shale gas gathering pipelines. Critical flow velocities at 10 degrees, 20 degrees, and 30 degrees were determined to be 8.25 m/s, 9.5 m/s, and 11 m/s, respectively. These critical flow velocities serve as references for efficient liquid discharge in engineering. By combining the flow process with corrosion studies, the main cause and sensitive areas of flow-accelerated corrosion were identified, and recommendations were proposed to prevent pipeline accelerated corrosion, thus minimizing the impact of flow-accelerated corrosion in shale gas pipelines.
ENGINEERING FAILURE ANALYSIS
(2023)
Article
Engineering, Chemical
Qing Han, Mengqing Shi, Linkai Han, Di Liu, Mingwei Tong, Yuxin Xie, Zhonghua Xiang
Summary: Developing highly efficient bifunctional oxygen electrocatalysts is crucial for zinc-air flow batteries. Metal-organic frameworks (MOFs) and covalent organic polymers (COPs) have emerged as promising alternatives due to their designable and controllable atomic-level structures. However, their catalytic performances are limited by conductivity and catalytic activity. In this study, nanosheet FeNi-MOF and iron phthalocyanine rich COP hybrid materials are assembled through the pi-pi stacking effect to create highly efficient bifunctional electrocatalysts. The resulting catalyst exhibits superior catalytic performance and stability, making it a promising candidate for zinc-air flow batteries.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Daria Grigorash, Dmytro Mihrin, Rene Wugt Larsen, Erling H. Stenby, Wei Yan
Summary: The article introduces a new approach to describe the cross-association between molecules, allowing for the simulation of weakly bound molecular complexes with different conformations in mixtures. By incorporating this approach into the equation of state, accurate predictions of vapor-liquid equilibrium and liquid-liquid equilibrium can be made. The new method is validated through experiments on alcohol and acid mixtures, with the results compared to experimental data, demonstrating its accuracy and reliability.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Mohammed Al-Sharabi, Daniel Markl, Vincenzino Vivacqua, Prince Bawuah, Natalie Maclean, Andrew P. E. York, Axel Zeitler
Summary: This study used terahertz pulsed imaging to investigate the transport process of different solvents into ceramic catalytic materials. The results showed that the heating rate of the samples influenced the water transport rate, while the viscosity of 1-octanol slowed down its transport.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Chukwunonso Anyaoku, Sati Bhattacharya, Rajarathinam Parthasarathy
Summary: This study aimed to enhance understanding of settling dynamics in viscoelastic fluids by developing a semi-empirical correlation and a dimensionless ratio, which accurately described the characteristics of settling suspensions.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Antti I. Koponen, Janika Viitala, Atsushi Tanaka, Baranivignesh Prakash, Olli-Ville Laukkanen, Ari Jasberg
Summary: This study focuses on the development of foam application chemicals for the paper and board industry. The research explores the rheology of the polyvinyl alcohol foam used in the process. Measurements were conducted to determine the foam viscosity and slip flow. The results suggest that slip flow contributes significantly to the total flow rate, and the obtained viscosity and slip models provide a solid foundation for industrial processes.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Dalei Sun, Jinghui Cai, Yating Yang, Zhiwu Liang
Summary: In this study, Fe-doped alpha-Bi2O3 catalysts with different Fe/Bi molar ratios were synthesized and utilized in the carbonylation of isobutyl amine with CO2. The results showed that Fe doping significantly enhanced the catalytic abilities of alpha-Bi2O3.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Yuan Tian, Xinxin Wang, Yanrong Liu, Wenping Hu
Summary: This paper predicts the solubility of nitrogen gas in ionic liquids (ILs) using two quantitative structure-property relationship (QSPR) models. By combining machine learning methods and ionic fragments contribution method, the accuracy and reliability of the prediction models are improved.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Liwang Wang, Wei Liu, Pan Yang, Yulong Chang, Xiaoxu Duan, Lingyu Xiao, Yaoming Hu, Jiwei Wu, Liang Ma, Hualin Wang
Summary: This study investigates the effective phase interfacial area (ae) of hydro-jet cyclones at different injection angles. The results show that a 45 degrees upward incidence angle yields the most favorable flow field characteristics for efficient mass transfer. The significant enhancement in ae of the hydro-jet cyclones offers the advantage of reducing equipment volume and cost savings.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Chuanjun Wu, Jiangzhi Chen, Jiyue Sun, I-Ming Chou, Shenghua Mei, Juezhi Lin, Lei Jiang
Summary: In this study, the solubility of H2S hydrate in water was measured using Raman spectroscopy. The results showed that the solubility increases with temperature under certain equilibrium conditions, and the solubility also depends on pressure and temperature under different equilibrium conditions. A thermodynamic model based on the van der Waals-Platteeuw theory was developed to predict the solubility, demonstrating its accuracy.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Lorenzo Brivio, Serena Meini, Mattia Sponchioni, Davide Moscatelli
Summary: This study investigates the influence of three main parameters and proposes a kinetic model to predict the optimal operating conditions for high yield of dimethyl terephthalate (DMT) in the chemical recycling process of polyethylene terephthalate (PET).
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Hongju Lin, Fanhui Liao, Yanchang Chu, Mingyu Xie, Lun Pan, Yuanyuan Wang, Lijian Leng, Donghai Xu, Le Yang, Gangfeng Ouyang
Summary: A honeycomb NiCo/C-Na catalyst with a micro-meso-macroporous structure has been fabricated and shown to have significantly higher catalytic activity for the decarboxylation of fatty acids. It also proves to be efficient in upgrading sludge HTL bio-crude, resulting in a biofuel with decreased viscosity and increased density.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Xiaoxian Li, Rui Li, Min Lin, Mingde Yang, Yulong Wu
Summary: A series of coated non-noble metal porous carbon catalysts were synthesized and applied to the aqueous-phase deoxygenation of algal bio-oil. One of the catalysts showed excellent deoxygenation selectivity and catalytic activity at 250 degrees C. The catalyst exhibited good hydrothermal stability and the reaction mechanism was proposed based on product analysis and active site analysis.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
M. V. Chudakova, M. V. Popov, P. A. Korovchenko, E. O. Pentsak, A. R. Latypova, P. B. Kurmashov, A. A. Pimenov, E. A. Tsilimbaeva, I. S. Levin, A. G. Bannov, A. V. Kleymenov
Summary: A series of catalysts with different potassium contents were prepared using solution combustion synthesis and characterized using various techniques. The results showed that the potassium content affected the phase composition and texture of the catalysts. The addition of a small amount of potassium resulted in a change in particle size distribution, leading to higher hydrogen yield. The Ni-1%K2O/Al2O3 catalyst exhibited the highest hydrogen yield at temperatures of 675 and 750 degrees Celsius.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Aliakbar Roosta, Nima Rezaei
Summary: In this study, we modified the electrolyte cubic plus association equation of state (e-CPA EoS) and integrated it with two electrical conductivity models to estimate the electrical conductivity of 11 monovalent electrolyte solutions in water. The modified e-CPA model demonstrated better performance and the hybridization with electrical conductivity models resulted in two predictive models for estimating the electrical conduction of dilute and concentrated electrolyte solutions. These predictive models showed relative average percentage deviations (AARD) of 11.15% and 13.87% over wide ranges of temperature and electrolyte concentration.
CHEMICAL ENGINEERING SCIENCE
(2024)
Article
Engineering, Chemical
Haoren Niu, Jianzheng Wang, Qingzhu Jia, Qiang Wang, Jin Zhao, Fangyou Yan
Summary: A study developed two quantitative structure-property relationship models for the complexation performance of alpha- and beta-cyclodextrins and validated their stability and predictive ability through internal and external validation. The models showed robustness and satisfactory performance, as demonstrated by the experimental results and model validations. These models can effectively predict the binding constants between cyclodextrins and various types of molecules, providing valuable tools for cyclodextrin design.
CHEMICAL ENGINEERING SCIENCE
(2024)
