Removal of Inclusions from Molten Aluminium by Flotation in a Stirred Reactor: A Mathematical Model and a Computer Simulation

Inclusions removal by flotation in mechanically agitated vessels is widely used in liquid aluminium treatments. Originating from different sources (oxide skins, refractory or recycling wastes), inclusions may have disastrous repercussions, such as physical properties alterations of the final products or difficulties during forging processes.With the aim of both a better understanding of the physical processes acting during flotation and the optimization of the refining process, a mathematical modelling of the behaviour of the inclusions population has been set up. Agglomeration, flotation and settling of inclusions are considered here. The model is divided in two steps: a 3D calculation of the biphasic liquid aluminium/bubbles fluid flow based on an Euler/Lagrange approach and a population balance. The population balance is performed with the assumption of a perfectly stirred reactor, and the calculation of agglomeration and flotation rates relies on mean values of fluid flow properties provided by the CFD simulation. Kruis & Kusters' model is employed for the calculation of the agglomeration rate and Kostoglou's model is used for the flotation rate. The fixed pivot method of Kumar & Ramkrishna is employed for the resolution of the population balance equation.A laboratory scaled flotation vessel is modeled and results of a simulation are presented.

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Intelligent diagnosis and analysis of brain lymphoma based on imaging features

Journal of Intelligent & Fuzzy Systems ◽

10.3233/jifs-189808 ◽

2021 ◽

pp. 1-11

Author(s):

Yipu Mao ◽

Muliang Jiang ◽

Fanyu Zhao ◽

Liling Long

Keyword(s):

Imaging Techniques ◽

Experimental Studies ◽

Diagnostic Value ◽

Imaging Features ◽

Flow Properties ◽

Brain Lymphoma ◽

Diagnosis And Prognosis ◽

Primary Brain Lymphoma ◽

Set Up ◽

Prognosis Evaluation

Currently, DSC has been extensively studied in the diagnosis, differential diagnosis and prognosis evaluation of brain lymphoma, but it has not obtained a uniform standard. By combining DSC imaging features, this study investigated the imaging features and diagnostic value of several types of tumors such as primary brain lymphoma. At the same time, this study obtained data from brain lymphoma patients by data collection and set up different groups to conduct experimental studies to explore the correlation between IVIM-MRI perfusion parameters and DSC perfusion parameters in brain lymphoma. Through experimental research, it can be seen that the combination of two perfusion imaging techniques can more fully reflect the blood flow properties of the lesion, which is beneficial to determine the nature of the lesion.

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Energy budget in internal wave attractor experiments

Journal of Fluid Mechanics ◽

10.1017/jfm.2019.741 ◽

2019 ◽

Vol 880 ◽

pp. 743-763 ◽

Cited By ~ 1

Author(s):

Géraldine Davis ◽

Thierry Dauxois ◽

Timothée Jamin ◽

Sylvain Joubaud

Keyword(s):

Velocity Field ◽

Internal Wave ◽

Boundary Layers ◽

Energy Budget ◽

Dissipation Rate ◽

Theoretical Expression ◽

Two Dimensional ◽

Energy Sink ◽

Set Up ◽

Different Sources

The current paper presents an experimental study of the energy budget of a two-dimensional internal wave attractor in a trapezoidal domain filled with uniformly stratified fluid. The injected energy flux and the dissipation rate are simultaneously measured from a two-dimensional, two-component, experimental velocity field. The pressure perturbation field needed to quantify the injected energy is determined from the linear inviscid theory. The dissipation rate in the bulk of the domain is directly computed from the measurements, while the energy sink occurring in the boundary layers is estimated using the theoretical expression for the velocity field in the boundary layers, derived recently by Beckebanze et al. (J. Fluid Mech., vol. 841, 2018, pp. 614–635). In the linear regime, we show that the energy budget is closed, in the steady state and also in the transient regime, by taking into account the bulk dissipation and, more importantly, the dissipation in the boundary layers, without any adjustable parameters. The dependence of the different sources on the thickness of the experimental set-up is also discussed. In the nonlinear regime, the analysis is extended by estimating the dissipation due to the secondary waves generated by triadic resonant instabilities, showing the importance of the energy transfer from large scales to small scales. The method tested here on internal wave attractors can be generalized straightforwardly to any quasi-two-dimensional stratified flow.

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Nanoparticle Precipitation in a T-Mixer: Coupling Experimental and Numerical Investigations of the Fluid Dynamics With the Solid Formation Processes

Volume 1: Symposia, Parts A and B ◽

10.1115/fedsm2006-98092 ◽

2006 ◽

Author(s):

Johannes Gradl ◽

Florian Schwertfirm ◽

Hans-Christoph Schwarzer ◽

Hans-Joachim Schmid ◽

Michael Manhart ◽

...

Keyword(s):

Flow Field ◽

Fluid Dynamic ◽

Concentration Field ◽

Population Balance ◽

Mixing Process ◽

Image Velocimetry ◽

Modeling Material ◽

Field Information ◽

Set Up ◽

3D Information

Mixing and consequently fluid dynamic is a key parameter to tailor the particle size distribution (PSD) in nanoparticle precipitation. Due to fast and intensive mixing a static T-mixer configuration is capable for synthesizing continuously nanoparticles. The flow and concentration field of the applied mixer is investigated experimentally at different flow rates by Particle Image Velocimetry (PIV) and Laser Induced Fluorescence (LIF). Due to the PIV measurements the flow field in the mixer was characterized qualitatively and the mixing process itself is quantified by the subsequent LIF-measurements. A special feature of the LIF set up is to detect structures in the flow field, which are smaller than the Batchelor length. Thereby a detailed insight into the mixing process in a static T-Mixer is given. In this study a CFD-based approach using Direct Numerical Simulation (DNS) in combination with the solid formation kinetics solving population balance equations (PBE) is applied, using barium sulfate as modeling material. A Lagrangian Particle Tracking strategy is used to couple the flow field information with a micro mixing model and with the classical theory of nucleation. We found that the DNS-PBE approach including macro and micro mixing, combined with the population balance is capable of predicting the full PSD in nanoparticle precipitation for different operating parameters. Additionally to the resulting PSD, this approach delivers a 3D-information about all running subprocesses in the mixer, i.e. supersaturation built-up or nucleation, which is visualized for different process variables.

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Load Characteristics of Steel and Concrete Tubular Members Under Jet Fire: An Experimental and Numerical Study

29th International Conference on Ocean, Offshore and Arctic Engineering: Volume 2 ◽

10.1115/omae2010-20754 ◽

2010 ◽

Author(s):

Jeong Hyo Park ◽

Bong Ju Kim ◽

Jung Kwan Seo ◽

Jae Sung Jeong ◽

Byung Keun Oh ◽

...

Keyword(s):

Cfd Simulation ◽

Numerical Study ◽

Fire Load ◽

Adiabatic Wall ◽

Fire Engineering ◽

Ansys Cfx ◽

Design Values ◽

Computational Fluid Dynamics Cfd ◽

Load Characteristics ◽

Set Up

The aim of this study was to evaluate the load characteristics of steel and concrete tubular members under jet fire, with the motivation to investigate the jet fire load characteristics in FPSO topsides. This paper is part of Phase II of the joint industry project on explosion and fire engineering of FPSOs (EFEF JIP) [1]. To obtain reliable load values, jet fire tests were carried out in parallel with a numerical study. Computational fluid dynamics (CFD) simulation was used to set up an adiabatic wall boundary condition for the jet fire to model the heat transfer mechanism. A concrete tubular member was tested under the assumption that there is no conduction effect from jet fire. A steel tubular member was tested and considered to transfer heat through conduction, convection, and radiation. The temperature distribution, or heat load, was analyzed at specific locations on each type of member. ANSYS CFX [2] and Kameleon FireEx [3] codes were used to obtain similar fire action in the numerical and experimental methods. The results of this study will provide a useful database to determine design values related to jet fire.

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On-demand Electrohydrodynamic Jetting of an Ethylene Glycol and Water Mixture—System of Controlled Picoliter Fluid Deposition

Journal of Imaging Science and Technology ◽

10.2352/j.imagingsci.technol.2021.65.4.040405 ◽

2021 ◽

Author(s):

J. F. Dijksman ◽

U. Stachewicz

Keyword(s):

Fluid Flow ◽

Power Amplifier ◽

Large Diameter ◽

Electrical Circuit ◽

Viscous Drag ◽

Water Mixture ◽

Electrical Field ◽

On Demand ◽

Flat Substrate ◽

Set Up

On-demand electrohydrodynamic jetting also called electrohydrodynamic atomization (EHDA) is a method to jet small amounts of fluid out of a nozzle with a relatively large diameter by switching on and off an electrical field between the nozzle and the substrate. The total amount of volume deposited is up to 5 pL. The set-up consists of a vertically placed glass pipette with a small nozzle directed downward and a flat substrate placed close to the end of the nozzle. Inside the pipette, an electrode is mounted close to the entrance of the nozzle. The electrode is connected to a high voltage power amplifier. Upon switching on the electrical field, the apparent surface tension drops, the meniscus deforms into a cone and fluid starts to flow toward the nozzle deforming the meniscus. At a certain moment the cone reaches the Taylor cone dimensions and from its tip a jet emerges that decomposes into a stream of charged fL droplets that fly toward the substrate. This process stops when the pulse is switched off. After switching off, the meniscus returns slowly to its equilibrium position. The process is controlled by different time constants, such as the slew rate of the power amplifier and the RC time of the electrical circuit composed of the electrical resistance in the fluid contained in the nozzle between the electrode and the meniscus, and the capacitance of the gap between the meniscus and the flat substrate. Another time constant deals with the fluid flow during the growth of the meniscus, directly after switching on the pulse. This fluid flow is driven by hydrostatic pressure and opposed by a viscous drag in the nozzle. The final fluid flow during droplet formation is governed by the balance between the drag of the charge carriers inside the fluid, caused by the current associated with the charged droplets leaving the meniscus and the viscous drag. These different phenomena will be discussed theoretically and compared to experimental results.

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Two-phase fluid flow properties of cataclastic fault rocks: Implications for CO2 storage in saline aquifers

Geology ◽

10.1130/g32508.1 ◽

2012 ◽

Vol 40 (1) ◽

pp. 39-42 ◽

Cited By ~ 11

Author(s):

Christian Tueckmantel ◽

Quentin J. Fisher ◽

Tom Manzocchi ◽

Sergey Skachkov ◽

Carlos A. Grattoni

Keyword(s):

Fluid Flow ◽

Co2 Storage ◽

Saline Aquifers ◽

Flow Properties ◽

Two Phase ◽

Fault Rocks ◽

Phase Fluid

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Effects of mudcake on the measurement of fluid flow properties using borehole acoustic waves

10.1190/1.1931993 ◽

1994 ◽

Author(s):

Xiao Ming Tang

Keyword(s):

Fluid Flow ◽

Acoustic Waves ◽

Flow Properties

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EFFECTS OF DIFFERENT TYPES OF CYTOPLASM ON THE KERNEL ROW NUMBER OF MAIZE INBRED LINES

AGROFOR ◽

10.7251/agreng1702155j ◽

2018 ◽

Vol 2 (2) ◽

Cited By ~ 1

Author(s):

Snežana JOVANOVIĆ ◽

Goran TODOROVIĆ ◽

Nikola GRČIĆ ◽

Ratibor ŠTRBANOVIĆ ◽

Rade STANISAVLJEVIĆ ◽

...

Keyword(s):

Environmental Factors ◽

Block Design ◽

Inbred Lines ◽

Mean Values ◽

Maize Inbred Lines ◽

Different Types ◽

Maize Inbreds ◽

Set Up ◽

Kernel Row Number

The aim of the present study was to determine effects of both, different types ofcytoplasm (cms-C, cms-S and fertile) and environmental factors on the kernel rownumber of 12 maize inbreds lines. The trial with inbred lines was set up in twolocations (Zemun Polje-Selection field and Zemun Polje-Školsko dobro) in 2013and 2014. Moreover, the three-replicate trials were set up according to therandomised complete block design within each type of cytoplasm. Each plot withinthe replicate consisted of four rows. Fertile versions of inbred lines were sown intwo border rows and they were pollinators for their sterile counterparts. Statisticbiometricdata processing was based on mean values per replicate and included theanalysis of variance. According to this analysis, significant differences in thekernel row number were established among inbred lines in dependence on the typeof cytoplasm, year and the location. The average kernel row number ranged from10.3 (L9) to 15.8 (L5 and L7). The variation of the kernel row number, related to thesource of cytoplasm, was very significant. Differences (Lsd0.01) in the kernel rownumber were not determined in inbred lines L5, L8, L10 and L12 in regard to the typeof cytoplasm: cms-C, cms-S and fertile. The average kernel row numbersignificantly (P1%) varied in regard to the year of investigation. A higher averagevalue (13.75) was established in 2014 than in 2013 (13.31). The kernel row numberper year very significantly varied (Lsd0.01) in all inbreds, but the differences werenot significant in the inbreds L2, L3, L8, L9 and L12. Gained results point out toeffects of different types of cytoplasm on the kernel row number.

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