Article
Mechanics
Yu-Eop Kang, Sunwoong Yang, Kwanjung Yee
Summary: This study proposes a physics-aware reduced-order modeling (ROM) approach that utilizes interpretable and information-intensive latent variables (LVs) extracted by a beta-variational autoencoder. The independence and information intensity of these LVs are quantitatively scrutinized, and their physical meanings are thoroughly investigated. The proposed physics-aware ROM is compared with conventional ROMs, and its validity and efficiency are successfully verified.
Article
Mechanics
Yu-Eop Kang, Sunwoong Yang, Kwanjung Yee
Summary: This study proposes a physics-aware ROM that utilizes interpretable and information-intensive LVs, which correspond to the generating factors of the training dataset, Mach number, and angle of attack, as confirmed through quantitative analysis in a two-dimensional transonic flow benchmark problem.
Article
Engineering, Chemical
Ai Wang, Mohammad Mainul Hoque, Geoffrey Evans, Subhasish Mitra
Summary: This study numerically computed the collision efficiency in a multi-bubble-particle system and investigated the effects of solids concentration and turbulence intensity. The results showed that in a monolayer configuration, side-by-side collisions did not occur, while in a multilayer configuration, particles had a chance to collide with trailing bubbles, resulting in higher collision efficiency. The modeling results also demonstrated that the energy dissipation rate increased with the number of bubbles per layer, number of bubble layers, turbulence intensity, and solids concentration.
MINERALS ENGINEERING
(2022)
Article
Mechanics
Mehdi Samiee, Ali Akhavan-Safaei, Mohsen Zayernouri
Summary: The study focuses on developing a tempered fractional-order modeling framework to address non-local interactions and intermittent signals in homogeneous isotropic turbulence. Through optimization of model parameters and efficiency evaluation, the tempered fractional subgrid-scale model shows potential in meeting requirements and enhancing efficiency.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Engineering, Marine
Jaeyoung Song, Jun Kayano, Ruri Shoji
Summary: Predicting and responding to vessel collision avoidance course is crucial for navigational safety. In order to predict the course for collision avoidance decisions, a model of human decisions needs to be established to avoid potential collision situations. This study developed a supervised learning-based ensemble classification model to simulate human collision avoidance decisions. Ship trajectory data was used to construct predictor and outcome variables, and the collision-avoidance algorithm's results were included in the prediction variables. The resulting well-fitted model provides insights into predicting the relationship between the output avoidance direction and the algorithm's variables.
Article
Engineering, Chemical
S. Li, M. P. Schwarz, Y. Feng, P. Witt, C. Sun
Summary: This paper investigates the effect of turbulence on the efficiency of collision between particles and bubbles using a computational fluid dynamics method to establish a bubble-particle collision efficiency model system. The study found that large-scale turbulence can increase collision speed, while small-scale turbulence affects collision efficiency through particle trajectory fluctuations.
MINERALS ENGINEERING
(2021)
Article
Engineering, Chemical
Ai Wang, Mohammad Mainul Hoque, Geoffrey Evans, Subhasish Mitra
Summary: In this study, the bubble-particle collision efficiency in a single-bubble system was investigated for different turbulence intensities and particle sizes. An analytical model was proposed to quantify the turbulence collision efficiency and compared with a computational fluid dynamics (CFD) model. It was found that the collision efficiency and effective particle releasing radius increased with turbulence intensity and particle diameter. The CFD model showed that higher turbulence intensity resulted in increased energy dissipation rate and more stochastic particle trajectories.
MINERALS ENGINEERING
(2022)
Article
Optics
Dengke Xing, Mao Feng, Congcong Liu, Jiangyong He, Kun Chang, Jin LI, Pan Wang, Yange Liu, Zhiq Wang
Summary: In this paper, we demonstrate spatiotemporal mode-locking in a step-index fiber cavity by compensating for modal dispersion and differential modal gain using long-period fiber grating. The grating, inscribed in few-mode fiber, induces strong mode coupling based on a dual-resonance coupling mechanism, with a wide operation bandwidth. By applying dispersive Fourier transform and intermodal interference, we show the stable phase difference between the transverse modes constituting the spatiotemporal soliton. These findings are significant for the study of spatiotemporal mode-locked fiber lasers.
Article
Astronomy & Astrophysics
L. Adhikari, G. P. Zank, D. Telloni, L-L Zhao
Summary: This study presents the first theoretical modeling of joint Parker Solar Probe (PSP)-Metis/Solar Orbiter (SolO) quadrature observations. The results show that the observed solar wind speed and density are consistent with the theoretical predictions, and the slow solar wind is found to be highly Alfvenic. The study also demonstrates the similarity between theoretical and PSP measurements in terms of slab fluctuations and turbulence pressure.
ASTROPHYSICAL JOURNAL LETTERS
(2022)
Article
Thermodynamics
Vishnu Nair, Benjamin Devenish, Maarten van Reeuwijk
Summary: The preferential concentration of sedimenting particles in decaying homogeneous isotropic turbulence is studied using radial distribution functions. Direct numerical simulations show a power law behavior for the RDF in decaying turbulence, and the power-law relation derived for non-sedimenting particles also holds for sedimenting particles. Empirical formulas are generated for the power-law coefficients, which are functions of the Stokes number and the Taylor Reynolds number for sedimenting particles. In-depth analysis confirms that gravity enhances the collision kernel for unequal-sized particles and decreases for same-sized particles. Models are created to predict kinematic collision kernels for both non-sedimenting and sedimenting particles, taking into account the effect of turbulence.
FLOW TURBULENCE AND COMBUSTION
(2023)
Article
Environmental Sciences
Berengere S. Dejeans, Julia C. Mullarney, Iain T. MacDonald
Summary: The study examines velocity and turbulence patterns in a sediment-laden river, revealing deficiencies in model performance in simulating turbulent kinetic energy dissipation rates, particularly around river bends. Results indicate that turbulence distributions show larger variations vertically than longitudinally, with the river's bathymetry and geometry playing a key role in controlling turbulence structure.
WATER RESOURCES RESEARCH
(2022)
Article
Engineering, Aerospace
Reza Djeddi, James G. Coder, Kivanc Ekici
Summary: This study utilizes an adjoint-based gradient optimization framework to calibrate critical amplification factors for transition models, improving the prediction capabilities for transition onset locations and aerodynamic characteristics.
Article
Computer Science, Interdisciplinary Applications
L. Fang, T. W. Bao, W. Q. Xu, Z. D. Zhou, J. L. Du, Y. Jin
Summary: This paper discusses the introduction of machine learning (ML) approaches in Reynolds-Averaged Navier-Stokes (RANS) modeling. The ML-RANS models are trained from a flow database and used in simulations of various flow cases. The paper aims to evaluate the applicability of ML-RANS models when there are differences in physics between the training flows and real simulations, and also analyzes the expansibility of constraints.
COMPUTERS & FLUIDS
(2022)
Article
Engineering, Civil
Sho Oh
Summary: This study proposes a spectral model and a series of models to predict turbulence spectra and model coefficients under unstable, neutral, and stable conditions based on offshore measurements. The model coefficients are related to the energy intensity and peak frequency in each frequency region. The results show that the turbulence spectrum characteristics under unstable to neutral conditions can be well described using the local similarity theory, while only the behavior of the inertial subrange can be accurately estimated for stable conditions. Comparison of measurements conducted over the sea suggests the influence of mesoscale turbulence on the differences in peak frequency and overall standard deviations for stable conditions.
JOURNAL OF WIND ENGINEERING AND INDUSTRIAL AERODYNAMICS
(2023)
Article
Engineering, Aerospace
Beatrice Latini, Matteo Fiore, Francesco Nasuti
Summary: The design of thrust chambers for modern liquid rocket engines is evolving towards additive layer manufacturing techniques, which offer advantages in customization, flexibility, and cost and time savings. However, the manufacturing process can result in high surface roughness in cooling channels, leading to increased friction and heat transfer. This study extends a correction to the turbulence model to account for high roughness in external flows, allowing for more accurate prediction of convective heat transfer coefficient values.
AEROSPACE SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Chemical
Benjamin De Castro, Mostafa Benzaazoua, Soumali Roychowdhury, Aurelie Chopard, Francis Quintal Lauzon, Benoit Plante
Summary: This study proposes an innovative method using deep learning algorithm and reflected light optical imaging to automatically detect all particles and minerals in acrylic resin polished sections. The experimental results show that this method can accurately detect all mineral particles, including transparent minerals, under reflected light optical microscopy, and provide unbiased mineralogical quantification.
MINERALS ENGINEERING
(2024)
Article
Engineering, Chemical
Qiushi Song, Xinyu Du, Changlu Shan, Hongwei Xie, Zhiqiang Ning, Kai Yu
Summary: This study investigated the effect of magnetic stirring on the microstructure of Co deposits during electrowinning in a chloride solution. It was found that magnetic stirring effectively reduced the negative influence of H2 bubbles on the structure of Co deposits and changed their nucleation and growth behavior, resulting in the preparation of high-quality columnar Co crystals.
MINERALS ENGINEERING
(2024)
Article
Engineering, Chemical
Tao Ge, Xiaowei Zhou, Liang Xu, Yan Sun, Cheng Yang, Yongpan Tian, Zhuo Zhao
Summary: In this study, the extraction performance and complexation mechanism of p-di-ethyl-amino-methylthiacalix[4]arene (L) towards Pt(IV) were investigated. The results indicated that L had excellent complexation ability towards Pt(IV) and could selectively extract it from a solution containing multiple competing ions.
MINERALS ENGINEERING
(2024)
Article
Engineering, Chemical
Yuan Li, Dirk van Zyl
Summary: This paper presents a modified Kynch's approach to explain the hindered settling behavior of suspensions impacted by segregation. The experimental data and predicted results confirm the effectiveness of the proposed method.
MINERALS ENGINEERING
(2024)
Article
Engineering, Chemical
Yi Fang, Aurora Robledo-Cabrera, Changsheng Peng, Shan Huang, Qi Xiao, Alejandro Lopez-Valdivieso
Summary: With the assistance of mechanical ball milling, the partially oxidized micro-sponge iron (micro-Fe0@Fe2O3) achieves significantly improved removal of Cr(VI) across a broad pH range. Mechanical force eliminates the surface oxide layer and exposes the Fe0 core, leading to sustained reduction of Cr(VI). The efficiency of micro-Fe0@Fe2O3 is strongly influenced by dissolved oxygen, with higher DO resulting in the generation of stable reductant Fe(II) under acidic conditions, while DO consumption hinders the reduction of Cr(VI) under alkaline conditions due to increased pH. Parameters of ball milling operation, especially rotation speed, have a significant impact on the removal of Cr(VI).
MINERALS ENGINEERING
(2024)
Article
Engineering, Chemical
Alton F. Grabsch, Phillip D. Fawell, Michael G. Davies
Summary: High molecular weight partially hydrolysed polyacrylamide (PHPA) is commonly used in mineral exploration drilling to increase fluid viscosity and help maintain the suspension of fine particles. However, clarifying these suspensions can be difficult, and previous studies have found that anionic flocculants are ineffective. This study confirmed that nonionic flocculants can successfully aggregate the particles, indicating that the charged tails of adsorbed PHPA prevent anionic flocculants from accessing the particle surfaces.
MINERALS ENGINEERING
(2024)
Article
Engineering, Chemical
J. S. Guiral-Vega, L. Perez-Barnuevo, J. Bouchard, A. Ure, E. Poulin, C. Du Breuil
Summary: This paper introduces an approach that combines particle properties and process modeling to describe the behavior of iron ore in a laboratory-scale drum-type magnetic separator. Early information on iron ore processing behavior can be obtained through laboratory testing, automated mineralogy analysis, and process modeling.
MINERALS ENGINEERING
(2024)
Review
Engineering, Chemical
Sayed Janishar Anzoom, Ghislain Bournival, Seher Ata
Summary: This review discusses the benefits and challenges of coarse particle flotation, as well as recent developments in improving the process. Coarse particle flotation has various applications and offers advantages in technical, economic, and sustainability aspects. However, it also faces challenges such as particle detachment, transfer between phases, and persistence in the froth phase. Technological advancements, such as fluidized-bed flotation and processes enhancing bubble-particle attachment, have shown promising results in efficiently recovering larger particles.
MINERALS ENGINEERING
(2024)
Article
Engineering, Chemical
Yimei Xiao, Jinchan Feng, Bingqiao Yang, Huihua Luo, Fang Zhou
Summary: In this study, the use of fulvic acid as a depressant for the flotation separation of chalcopyrite from arsenopyrite was investigated. It was found that fulvic acid strongly depressed arsenopyrite while having little influence on chalcopyrite flotation. The addition of calcium hypochlorite facilitated the adsorption of fulvic acid on arsenopyrite surface.
MINERALS ENGINEERING
(2024)
Article
Engineering, Chemical
Bo Hao, Minqiang Fan
Summary: Particle-bubble attachment is crucial in coal and mineral flotation processes. In this study, the attachment process of low-rank coal particles to the bubble surface was simulated, revealing the important role of water film rupture in particle attachment.
MINERALS ENGINEERING
(2024)
Article
Engineering, Chemical
Shuwei Wu, Shuai Wang, Guoqiang Wang, Longfei Fan, Jianbo Guo, Zhengbin Liu, Haoyan Zhang, Wei Guan, Yukuan Wang, Yewei Wu
Summary: This study analyzes the motion mode of eccentric roller crushers and proposes a calculation method for productivity. Through laboratory experiments, the results indicate that the proposed method can effectively estimate the productivity of eccentric roll crushers.
MINERALS ENGINEERING
(2024)
Article
Engineering, Chemical
Hanna Miettinen, Malin Bomberg, Ozlem Bicak, Zafir Ekmekci, Paivi Kinnunen
Summary: Mineral processing requires large amounts of water, and reducing water consumption through recirculation and closing water loops is important. However, this can lead to the accumulation of contaminants in the process water, which can negatively affect the process performance. In this study, the impact of microorganisms on flotation performance was investigated, and ion exchange was evaluated for removing dissolved sulfur species and microorganisms from water. The results showed that adding microorganisms had a positive effect on flotation selectivity, especially for nickel. Different water types, process water and final tailings water, behaved slightly differently. Ion exchange proved to be effective in removing sulfur species and microorganisms, and dissolved air flotation was a successful pretreatment for ion exchange in removing microorganisms.
MINERALS ENGINEERING
(2024)
Article
Engineering, Chemical
Canneng Chen, Song Zhang, Quanjun Liu, Luzheng Chen, Yongjun Xian, Yijie Wang
Summary: This study introduces the use of ultrasonic pretreatment to enhance the flotation separation of elemental sulfur and silver-bearing lead minerals from ultrafine residue. The results show that ultrasonic pretreatment effectively liberates associated sulfur and improves the separation of sulfur and silver-bearing lead minerals. Under optimized conditions, ultrasonic pretreatment significantly improves the recovery and grade of sulfur in the concentrate, as well as the recovery of lead and silver in the tailings.
MINERALS ENGINEERING
(2024)
Article
Engineering, Chemical
Genzhuang Li, Fisher Wang, Bern Klein, Michael Deal, Aaron Wright, Hector Mezquita
Summary: This paper presents a stress-based approach for predicting and improving large-scale HIG mill performance through experimental testing and model calibration.
MINERALS ENGINEERING
(2024)
Article
Engineering, Chemical
Runpeng Liao, Shuming Wen, Jian Liu, Shaojun Bai, Qicheng Feng
Summary: This study demonstrates that the use of a DDA/DDTC mixed collector system can significantly improve the flotation performance of smithsonite. The synergistic effect between DDA and DDTC is confirmed, and the mixed collector system contributes to a decrease in solution surface tension. The use of FT-IR and XPS confirms the simultaneous physisorption and chemisorption of DDA and DDTC on the smithsonite surface, and contact angle measurements show that the mixed collector effectively enhances the hydrophobicity of smithsonite. Molecular dynamics simulations reveal the multilayer adsorption of DDTC and DDA on the smithsonite surface, with DDTC promoting the adsorption of DDA.
MINERALS ENGINEERING
(2024)