Article
Engineering, Chemical
Farooq Hussain, Maciej Jaskulski, Marcin Piatkowski, Evangelos Tsotsas
Summary: Particle size distribution is crucial in spray dryers, and controlling agglomeration and coalescence is key. The study presents a CFD model to accurately predict particle size and product properties.
CHEMICAL ENGINEERING SCIENCE
(2022)
Article
Physics, Multidisciplinary
Can Peng, Xianghua Xu, Xingang Liang
Summary: Partial coalescence is a complex flow phenomenon that involves a downward high-velocity region affecting droplet shape and coalescence transition. Droplets tend to transition from partial to full coalescence when their shape approaches a sphere before pinch-off. Factors influencing the coalescence process include film thickness, surface tension coefficient, initial droplet diameter, and impact velocity.
Article
Chemistry, Multidisciplinary
Cong Zhang, Yuqi Zhang, Huadong Zhao, Mao Wang, Tongtong Wang
Summary: The study revealed that an increase in sediment concentration linearly leads to a rise in maximum erosion on the spillway, while an increase in sediment diameter initially increases erosion, then decreases. Flow velocity results in varying trends of erosion growth, and gate opening significantly affects erosion at the bottom.
APPLIED SCIENCES-BASEL
(2021)
Article
Mechanics
Md Ashraful Islam, Albert Y. Tong
Summary: This study numerically analyzed the dynamics of drop formation from a vertical capillary tube, identifying the mechanism of satellite drop formation and liquid filament recoiling after droplet detachment. Parametric studies showed that inlet velocity, surface tension coefficient, and viscosity play important roles in satellite droplet generation.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2022)
Article
Chemistry, Physical
M. R. Mardani, D. D. Ganji, Kh Hosseinzadeh
Summary: This study investigates the movement and coalescence of dual droplets in a channel exposed to an external electric field. Computational fluid dynamics is used to develop an electro hydrodynamic and electrostatic model. The results show that increasing velocity decreases the coalescence time of the droplets, while increasing the electrostatic field intensity reduces the coalescence time and improves the coalescence efficiency.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Environmental Sciences
Luming Cha, Chiyu Xie, Qihong Feng, Matthew Balhoff
Summary: Snap-off is a phenomenon where non-wetting fluid is displaced by wetting fluid in pore-throat channels, leading to droplet breakup at the throat. Geometric criteria for capillary snap-off in 2D microchannels with rectangular cross-sections have been derived, providing guidelines for the design of micromodels used in studying multiphase flow processes in porous media. The criteria are verified through numerical CFD simulations and validated using microfluidic experiments, clarifying previous debates in the literature.
WATER RESOURCES RESEARCH
(2021)
Article
Engineering, Marine
N. Karimi Asli, M. Rahmanpour, A. H. Mosaffa
Summary: In this study, a two-dimensional numerical model based on the realizable k-epsilon turbulent model was established to simulate the water entry and immersion process of three steel pipes attached to a concrete base. The effects of Froude Number on penetration depth and impact force were investigated. The numerical analysis revealed that the maximum force applied to the base of the structure increases suddenly with the increase of Froude Number and contact surface.
Article
Engineering, Chemical
Roman Filimonov, Zan Wu, Bengt Sunden
Summary: This work applied techniques to speed up CFD simulations for droplet generation and demonstrated good agreement with experimental data, showing promising potential for developing chips for droplet generation with significant time savings in research and design cycles.
CHEMICAL ENGINEERING RESEARCH & DESIGN
(2021)
Article
Engineering, Industrial
Angshuman Kapil, Nithin Kayarthaya, Vatsalya Sharma, Abhay Sharma
Summary: In recent years, on-demand metal droplet deposition has gained increased interest for its potential applications in additive manufacturing. Plasma metal inert gas droplet deposition (plasma MIG DD) allows for high-accuracy, minimal substrate melting, and minimal spatter and metal fume generation. This study develops a computational fluid dynamics-based simulation methodology to understand droplet dynamics and behavior during the deposition process. The results show that post-impingement droplet behavior is influenced by the initial droplet temperature and substrate material properties, with copper droplets exhibiting different shapes when impinging on copper or aluminum substrates. The study provides fundamental insights for optimization, process design, and reverse engineering in droplet-on-demand applications.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2023)
Article
Chemistry, Physical
J. Reiner, E. M. Walter, H. P. Karbstein
Summary: This study focuses on the assessment of droplet self-shaping, crystallization, and melting behavior during repeated cooling and heating cycles of oil-in-water emulsions. The results show that the shape symmetry of droplets can be broken during crystallization, depending on the surfactant molecular structure and cooling profile.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2023)
Article
Engineering, Chemical
Doston Shayunusov, Dmitry Eskin, Hongbo Zeng, Petr Nikrityuk
Summary: This study focuses on the numerical investigation of water droplet coalescence in bitumen. Using the Navier-Stokes equations coupled with the volume of fluid model (VOF) and adaptive grids techniques, the behavior of water droplets with different sizes in rapidly converging and diverging microchannels was analyzed. The simulations were validated against experimental data, showing good agreement. The results revealed that the bulk flow velocity in the channel is the main parameter influencing coalescence. Unsteady simulations indicated the existence of a critical flow velocity, above which no coalescence occurs. Additionally, image processing analysis was used to estimate the mean droplet size in different geometries, and it was found that late coalescence in a wider constriction significantly increased the mean size of droplets.
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
(2023)
Article
Engineering, Chemical
Peikun Liu, Wenxiu Fu, Lanyue Jiang, Yuekan Zhang, Xiaoyu Li, Xinghua Yang, Bo Chen
Summary: This study uses numerical simulation to investigate the effect of overflow back pressure on the internal flow field and separation performance of hydrocyclones. The results indicate that increasing the overflow back pressure leads to higher energy consumption, increased solid phase yield, higher content of fine particles, lower content of coarse particles, and reduced separation accuracy of the hydrocyclones.
Article
Thermodynamics
Wen-Ling Li, Jian-Hong Wang, Han Chen, Lei Shao, Guang-Wen Chu, Yang Xiang
Summary: A three-dimensional CFD model coupled with a mesoscale mass transfer model was developed to simulate CO2 absorption in a microporous tube-in-tube microchannel reactor. The simulation results were validated by experimental data, showing enhanced mass transfer due to local breakage and coalescence of gas-liquid interfaces. An entrance-effect zone was revealed, and the overall mass transfer coefficient enlarged significantly with a decrease in the length of the gas-liquid collision zone, providing a theoretical basis for further optimization of the reactor.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Mechanics
Weidong Yu, Shinan Chang, He Song
Summary: This study numerically investigates head-on ternary droplet collision of the same liquid in a gaseous environment. The shape and velocity field evolution of three colliding droplets are studied for a wide range of Weber number. Relevant correlations for the length and diameter of the ligament, length of the bridge, and maximum radial length are presented quantitatively based on the dimensionless flow parameters.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2023)
Article
Mining & Mineral Processing
Lingguo Meng, Shuling Gao, Dezhou Wei, Qiang Zhao, Baoyu Cui, Yanbai Shen, Zhenguo Song
Summary: The authors proposed an Eulerian multi-fluid volume of fluid (VOF) model to describe the particulate flow in spiral separators, incorporating the Bagnold effect to improve the model's applicability in high solid concentration systems. The model's capability was evaluated by comparing predicted flow film shapes with measured flow film thicknesses in a LD9 spiral separator, and the model showed good agreement with literature observations. Experimental and numerical simulations of quartz and hematite separation in a laboratory-scale spiral separator were also performed, and the inclusion of the Bagnold lift force model improved the predictions of iron grade and solid concentration.
INTERNATIONAL JOURNAL OF MINING SCIENCE AND TECHNOLOGY
(2023)
Article
Nanoscience & Nanotechnology
Gang Ruan, Chang Liu, Hongqiao Qu, Chuan Guo, Gan Li, Xinggang Li, Qiang Zhu
Summary: This paper compared the application of IN718 powders prepared by gas atomization (GA) and plasma rotating electrode process (PREP) in LPBF process. The results showed that the PREP powder had better flowability and processing window, and could achieve more stable mechanical properties compared to the GA powder.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Engineering, Mechanical
Yang Zhou, Wenying Qu, Fan Zhou, Xinggang Li, Lijun Song, Qiang Zhu
Summary: This study provides a deeper understanding of the interaction mechanism between the magnetic field and melt flow inside the molten pool, and offers practical references for the design of magnetic field-assisted L-DED equipment.
RAPID PROTOTYPING JOURNAL
(2023)
Article
Engineering, Chemical
Krischan Sandmann, Manuel Falcone, Lizoel Buss, Norbert Riefler, Kiyoumars Abdoly, Hergen Oltmann, Udo Fritsching
Summary: This study presents the numerical modeling and simulation of particle dispersion during the filling process of a tubular combustion chamber. The findings reveal typical particle accumulations near the reactor wall and analyze the particle segregation and accumulation effects aside vortex structures. The measures for reducing particle segregation and inhomogeneities are discussed.
CHEMIE INGENIEUR TECHNIK
(2023)
Article
Thermodynamics
Nithin Mohan Narayan, Saeedeh Imani Moqadam, Nils Ellendt, Udo Fritsching
Summary: This article introduces quenching as a widely applied heat treatment process for metallic materials and discusses the impact of process parameter selection on the results. It also presents a multiphase numerical modeling to analyze the cooling rate of high temperature semi-solid spheres quenched in water.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Optics
Chuan Guo, Gan Li, Fan Zhou, Xinggang Li, Chang Liu, Zhong Li, Qiang Zhu
Summary: This study aims to investigate the effect of boron on the cracking behavior of Inconel738LC during laser powder bed fusion, which has not been widely studied before. Two batches of Inconel738LC powders with different boron contents are used to fabricate parts. More cracks are found in the samples fabricated with high-boron powders compared to low-boron powders. The formation of boride is confirmed, leading to solidification cracking at the final stage of solidification. Cracks tend to occur at grain boundaries with high misorientation angles. Decreasing the boron content significantly improves the mechanical performance by reducing the level of cracking in the samples.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Thermodynamics
Shahram Mohammadi, Jalal Poostforooshan, Malte F. B. Stodt, Vinzent Olszok, Johannes Kiefer, Udo Fritsching, Alfred P. Weber
Summary: In this work, MnOx nanoparticles were synthesized by a continuous electrospray-assisted flame spray pyrolysis (EAFSP) method. The precursor solutions containing MnN dissolved in 1-propanol were atomized into charged droplets by electrospray and then enter the flame without dispersion gas. The high-temperature residence times of the droplets were controlled by varying the horizontal injection locations, resulting in MnOx nanoparticles with tunable properties. Various diagnostics were used to analyze the formation and crystal phases of the MnOx nanoparticles, and phase-Doppler anemometry experiments were conducted to study the combustion behavior of electrosprayed MnN droplets.
APPLICATIONS IN ENERGY AND COMBUSTION SCIENCE
(2023)
Article
Nanoscience & Nanotechnology
Chuan Guo, Gan Li, Sheng Li, Xiaogang Hu, Hongxing Lu, Xinggang Li, Zhen Xu, Yuhan Chen, Qingqing Li, Jian Lu, Qiang Zhu
Summary: The additive manufacturing of Ni-based superalloys has attracted significant attention for its ability to fabricate complex components for high-end industrial systems. However, the rapid heating and cooling processes can induce high levels of residual stress and lead to severe metallurgical defects. Understanding the mechanisms of residual stress and crack formation is crucial to prevent cracking and enable wider application of these materials. This paper reviews the residual stress and crack formation mechanisms in additively manufactured Ni-based superalloys and presents methods for inhibiting crack formation.
NANO MATERIALS SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Xi He, Gan Li, Yuhe Huang, Zhun Huang, Tao Wang, Xinggang Li, Qiang Zhu
Summary: Laser powder bed fusion (L-PBF) is an advanced method for fast prototyping high-performance metallic components with complex structures. The development of high-strength Al alloys using L-PBF is limited by hot cracks, which is addressed by introducing 3 wt% Ti2AlNb intermetallic (IMC) powders into 7075 Al powders to form an in-situ nucleated 7075 (IN-7075) Al alloy. The as-printed IN-7075 Al alloy showed crack-free behavior with refined grain size and exhibited good mechanical properties after suitable heat treatment.
Article
Biochemistry & Molecular Biology
Anja Heyse, Miriam M. Gossmann, Patrick Giefer, Patrizia Gaebel, Udo Fritsching, Anja M. Wagemans, Stephan Drusch
Summary: Fouling due to biomolecule adsorption remains a drawback for membrane emulsification. This study investigated the fouling effect on the membrane and the modified enzyme. Through experiments and simulations, it was found that increasing lipase concentration led to higher fouling and decreased wetting of the membrane. The pH of the lipase solution also affected the microstructure of the foulant layer. Despite enzyme mass loss, the structural and functional characteristics of lipase were not significantly affected.
PROCESS BIOCHEMISTRY
(2023)
Article
Engineering, Chemical
Udo Fritsching, Lizoel Buss, Teresa Tonn, Lukas Schumski, Jurgen Gakovi, Johnson David Hatscher, Jens Soelter, Kerstin Avila, Bernhard Karpuschewski, Julian Frederic Gerken, Tobias Wolf, Dirk Biermann, Christian Menze, Hans-Christian Moehring, Elio Tchoupe, Lukas Heidemanns, Tim Herrig, Andreas Klink, Kaissar Nabbout, Martin Sommerfeld, Fabian Luther, Ingo Schaarschmidt, Andreas Schubert, Markus Richter
Summary: Metalworking operations rely on the successful application of metalworking fluids (MWFs) for effective and efficient operation. This paper discusses promising flow visualization techniques applied to different machining processes, which can help determine efficient machining parameters and MWF applications.
Article
Thermodynamics
M. F. B. Stodt, J. Kiefer, U. Fritsching
Summary: Flame spray pyrolysis (FSP) is a technique for the synthesis of metal oxide nanoparticles by combusting precursor solutions in a spray flame. In this study, the influence of jet Reynolds number and turbulence on droplet dynamics and the synthesis of iron oxide nanoparticles by FSP is investigated. It is found that the presence of μ-explosions in the spray flame leads to the conversion of droplet sizes from unimodal to bimodal droplet size distribution (DSD). The results show that higher jet Reynolds numbers result in narrower DSD and sharper separation of DSD probability peaks.
APPLICATIONS IN ENERGY AND COMBUSTION SCIENCE
(2023)
Article
Thermodynamics
Pedro Bianchi Neto, Lizoel Buss, Malte F. B. Stodt, Udo Fritsching, Dirceu Noriler
Summary: In order to accurately model and simulate the flame spray pyrolysis process, all relevant phenomena must be considered. A combination of computational fluid dynamics (CFD) and a population balance model (PBM) is used to investigate the impact of thermophoresis and other parameters on particle size. The flame spray process is simulated using CFD and a monodisperse solver for a bivariate PBM is implemented to simulate nanoparticle formation and evolution. The model is validated using experimental data and shows accurate results for some cases.
APPLICATIONS IN ENERGY AND COMBUSTION SCIENCE
(2023)
Article
Engineering, Industrial
Zhiwei Lyu, Yutaka S. Sato, Wanghui Xu, Su Li, Zhen Xu, Xiaogang Hu, Xinggang Li, Qiang Zhu
Summary: This study improves the mechanical properties of as-WAAMed 17-4PH steel by utilizing the intrinsic heat treatment, resulting in higher tensile strength and elongation.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2023)
Article
Physics, Fluids & Plasmas
Manuel Falcone, Lizoel Buss, Udo Fritsching
Summary: This article analyzes a new vibration-assisted drilling process for the manufacturing of extremely hard materials. It applies multiphase computational fluid dynamics to study the MQL gas/liquid transport in the presence of a vibrating and rotating twist drill bit. The article utilizes an open-source Smoothed Particle Hydrodynamics (SPH) meshless method to overcome the limitations of conventional mesh-based methods in analyzing lubrication media flow. However, the study finds that the SPH method does not provide satisfactory results in terms of solution plausibility and computational cost.
Article
Physics, Fluids & Plasmas
Lizoel Buss, Yongli Qi, Julian Heidhoff, Oltmann Riemer, Udo Fritsching
Summary: This study applies a computational fluid dynamics (CFD) model to analyze the key phenomena in the interaction of the liquid suspension and the workpiece surface in microfluid jet polishing (MFJP). The numerical results indicate that shear stress strongly depends on the injection pressure of the liquid suspension and is weakly dependent on the abrasive suspension concentration.
