scholarly journals Fluid Flow Characterization of Single-Strand Tundish with Flow Modifiers through Physical Water Model (PWM) and CFD Simulation

2021 ◽  
Vol 12 (1) ◽  
pp. 211-221
Keyword(s):  
Fluid Flow ◽  
Residence Time ◽  
Cfd Simulation ◽  
Flow Behavior ◽  
Flow Characteristics ◽  
Steel Production ◽  
Single Strand ◽  
Experimental Simulation ◽  
Water Model ◽  
Inclusion Removal

The flow behavior in the continuous casting tundish dominates the quality and cleanliness of steel production. In this research, the single strand tundish's fluid flow behavior with different flow modifiers is investigated through numerical and experimental simulation. The numerical; simulation is performed in ANSYS FLUENT 19.2 (commercial package) and experimental through physical water model technique. The flow behaviors of bare tundish and tundish with three different flow modifiers are investigated. The three different flow modifiers deployed are the dam, baffle, and turbulence inhibiter (TI). Fluid flow performance is examined through residence time distribution (RTD) curves, which are derived from the measurement of the tracer concentration at the outlet. Good agreement between the CFD simulation and physical water model experiments is discovered. The results show there is an improvement in residence time and fluid flow (also improved inclusion removal) after the deployment of flow modifiers. There is a 20% improvement in peak and minimum residence time of RTD curves due to flow modifiers application. It is also discovered that the tundish configuration in this research, the tundish with turbulence inhibiter, provides optimal flow characteristics and eventually intended to promote a better level of inclusion removal.

Effects of Nano-Nozzles Cross-Sectional Geometry on Fluid Flow: Molecular Dynamic Simulation

2017 ◽  
Vol 34 (5) ◽  
pp. 667-678 ◽  
Author(s):  
H. Nowruzi ◽  
H. Ghassemi
Keyword(s):  
Fluid Flow ◽  
Velocity Profile ◽  
Cross Sections ◽  
Md Simulation ◽  
Flow Behavior ◽  
Water Model ◽  
Physical Parameters ◽  
Cross Sectional ◽  
Behavior Characteristics ◽  
Fanning Friction Factor

AbstractNano-nozzles are an essential part of the nano electromechanical systems (NEMS). Cross-sectional geometry of nano-nozzles has a significant role on the fluid flow inside them. So, main purpose of the present study is related to the effects of different symmetrical cross-sections on the fluid flow behavior inside of nano-nozzles. To this accomplishment, five different cross-sectional geometries (equilateral triangle, square, regular hexagon, elliptical and circular) are investigated by using molecular dynamics (MD) simulation. In addition, TIP4P is used for atomistic water model. In order to evaluate the fluid flow behavior, non-dimensional physical parameters such as Fanning friction factor, velocity profile and density number are analyzed. Obtained results are shown that the flow behavior characteristics appreciably depend on the geometry of nano-nozzle's cross-section. Velocity profile and density number for five different cross sections of nano-nozzle at three various measurement gauges are presented and discussed.

Physical water model and CFD studies of fluid flow in a single strand tundish

2018 ◽  
Vol 5 (3) ◽  
pp. 9220-9228
Author(s):  
Anawat Harnsihacacha ◽  
Adisorn Piyapaneekoon ◽  
Pruet Kowitwarangkul
Keyword(s):  
Fluid Flow ◽  
Single Strand ◽  
Water Model

A Device for Measuring Thin Fluid Flow Depth Over an Inclined Open Rectangular Channel

2009 ◽  
Vol 131 (10) ◽  
Author(s):  
A. K. Majumder
Keyword(s):  
Fluid Flow ◽  
Flow Behavior ◽  
Rectangular Channel ◽  
Flow Characteristics ◽  
Operating Conditions ◽  
Multiple Point ◽  
Flow Depth ◽  
Flow Rates ◽  
Law Of The Wall ◽  
Measured Flow

Accurate knowledge of the fluid flow depth over an inclined rectangular open channel is of obvious value in the modeling of flow characteristics over that channel. Understanding of this type of fluid flow behavior is of immense importance to the mineral processing fraternity as a large number of separators work on this principle. Therefore, a multiple point computer-controlled depth gauge was developed to measure water flow depths at various flow rates ranging from 0.81 l/s to 2.26 l/s over an inclined (17.5 deg) rectangular channel (2400 mm long and 370 mm wide). This paper describes the details about the device and the data acquisition procedure. An attempt has also been made to predict the measured flow depths at various operating conditions by using a modified form of the conventional law of the wall model. An overall relative error of 4.23% between the measured and the predicted flow depths at various flow rates establishes the validity of the model.

scholarly journals Fluid Flow Behavior of Sheared Rough Fractures Subjected to Different Stress State

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1055
Author(s):  
Min Wang ◽  
Qifeng Guo ◽  
Pengfei Shan ◽  
Yakun Tian ◽  
Bing Dai
Keyword(s):  
Fluid Flow ◽  
Normal Stress ◽  
Contact Area ◽  
Reverse Flow ◽  
Flow Behavior ◽  
Nonlinear Coefficient ◽  
Flow Characteristics ◽  
Shear Displacement ◽  
Navier Stokes Equation ◽  
Linear Coefficient

The hydraulic properties of fractures are greatly affected by the stress. Knowing the fluid flow behavior of fractures is of great importance to underground engineering construction and environmental safety. The main purpose of this paper is to study the fluid flow characteristics of rough fractures under different stress states. First, rough fracture surfaces were generated by using the corrected successive random addition (SRA) algorithm. Then, the sheared fracture models subjected to different stress condition were obtained under the boundary condition of constant normal stiffness (CNS). Finally, the hydraulic characteristics of the three-dimensional rough rock fractures were analyzed by numerically solving the full Navier–Stokes equation. It has been found that (1) the aperture of fractures all obeys the Gaussian distribution. The dilatancy effect is gradually obvious and aperture becomes larger with the increase of shear displacement. (2) When the initial normal stress increases, the contact area of fracture becomes larger and the reverse flow can be observed around the contact area. (3) The relationship between hydraulic gradient and flowrate exhibits nonlinearity which can be described by the Forchheimer’s law. The linear coefficient a and the nonlinear coefficient b gradually decrease with the increase of shear displacement and finally stabilize. The values of a and b are reduced by 1–2 and 1–3 orders of magnitude respectively during the shear. The critical Reynolds number increases with the increase of shear displacement and decrease as the initial normal stress increases.

Velocity Profile Investigation of FFS Microchannel at Re 100

2014 ◽  
Vol 487 ◽  
pp. 290-293
Author(s):  
Vithyacharan Retnasamy ◽  
Zaliman Sauli ◽  
Steven Taniselass ◽  
Nor Shakirina Nadzri ◽  
Tan Hsio Mei ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Fluid Flow ◽  
Velocity Profile ◽  
Velocity Distribution ◽  
Cross Sections ◽  
Flow Behavior ◽  
Flow Characteristics ◽  
Reynolds Numbers ◽  
Step Height ◽  
Forward Facing Step

Recently, microfluidics system has been widely employed in various areas for instance biomedical,pharmaceuticals and cell biological researchdue to its advantages. The flow behavior in microchannels with different cross-sections has been topic in previous studies. In this paper, numerical simulation of fluid flow in Forward Facing Step (FFS) configuration was performed to investigate velocity profile after the step. Reynolds numbers (Re) 100 with different step heights, 1μm and 3μm were used to observe trend occurs in the flow characteristics. The result illustrated an increase of velocity distribution with the increase of the step height.

Optimization of Weir & Dam with Drain Holes in Continuous Casting Slab Tundish

2012 ◽  
Vol 476-478 ◽  
pp. 293-301 ◽  
Author(s):  
Chao Chen ◽  
Guo Guang Cheng ◽  
Hai Bo Sun ◽  
Xin Chao Wang ◽  
Jia Quan Zhang
Keyword(s):  
Fluid Flow ◽  
Continuous Casting ◽  
Plug Flow ◽  
Flow Characteristics ◽  
Surface Flow ◽  
Water Model ◽  
Near Surface ◽  
Continuous Casting Slab ◽  
Flow Through ◽  
Fluid Flow Characteristics

The optimization of the location and height of weir & dam with drain holes in a single-strand continuous casting tundish was carried out from the view of fluid flow characteristics by physical modeling using a 0.4 scaled water model and mathematical modeling study. Considering simultaneously reducing the remaining melt, maximizing the plug flow and avoiding the short circuited flow, the dam with two upwardly inclined drain holes was optimized. The parameters such as location and height of weir & dam Lw/L, Ld/L, Hw/H and Hd/H are important to fluid flow in tundish. Among them, the location and height of dam were more critical to the overall fluid flow in tundish. The gap between weir and dam was also very important, the gap length that smaller than 0.266 will be preferred. The dead region behind the weir was enlarged and the tracer flow through the drain holes of dam was weakened as increasing the gap of weir and dam. In present study, the parameters of the optimized Case7 are Hw/H 0.448 (162/362), Hd/H 0.718 (260/362), Lw/L 0.4 (480/1200) and Ld/L 0.667 (800/1200). For the fluid flow field, the near surface flow which beneficial to inclusions removal existed both above the dam and through the upwardly inclined drain holes. While the case of bottom grooved dam used may lead to short circuited flow through the grooves.

Using Computational Fluid Dynamics (CFD) for Evaluation of Fluid Flow Through a Gate Valve

2012 ◽  
Vol 8 (4) ◽  
Author(s):  
Pedro Esteves Duarte Augusto ◽  
Marcelo Cristianini
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fluid Flow ◽  
Pressure Drop ◽  
Gate Valve ◽  
Flow Behavior ◽  
Flow Characteristics ◽  
Type Equation ◽  
Pharmaceutical Products ◽  
Computational Fluid Dynamics Cfd

Abstract Gate valves are the most common valve in industrial plants. However, there is no work in the literature regarding the use of computational fluid dynamics (CFD) to evaluate the fluid flow characteristics and pressure drop in gate valves. The present work evaluated the fluid flow and pressure drop through a commercial gate valve using CFD. The obtained values for the pressure loss coefficient (k) are in accordance to those described in the literature and a power type equation could be used for modeling it as function of the Reynolds Number. Fluid flow behavior through the gate valve highlighted the flow recirculation and stagnant areas, being critical for food and pharmaceutical products processing. The obtained results reinforce the advantages in using CFD as a tool for the engineering evaluation of fluid processes.

scholarly journals Numerical Investigation of Flow Characteristics of Molten Steel in the Tundish with Channel Induction Heating

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1937
Author(s):  
Bin Yang ◽  
Hong Lei ◽  
Yingshi Xu ◽  
Kun Liu ◽  
Peng Han
Keyword(s):  
Fluid Flow ◽  
Flow Pattern ◽  
Numerical Investigation ◽  
Induction Heating ◽  
Molten Steel ◽  
Flow Behavior ◽  
Plug Flow ◽  
Flow Characteristics ◽  
Main Flow ◽  
Mixed Flow

In the continuous process, fluid flow is an important physical phenomena in the tundish, as it affects the process of heat transfer, bubble motion and inclusion collision-coalescence and grow up. This paper undertakes a detailed numerical investigation of fluid flow characteristics in the tundish with and without induction heating. The individual unit method and the volume subtraction model are applied to analyze the flow characteristics. A quantitative evaluation method of flow characteristics is proposed to investigate the flow characteristics. In the tundish with and without induction heating, firstly, the main flow behavior of molten steel is mixed flow in the receiving chamber; secondly, the main flow behavior of molten steel is plug flow in the channel; lastly, the main flow pattern is mixed flow, and the minor flow pattern is plug flow in the discharging chamber. The method of the volume subtraction model is an effective way to analyze the flow characteristics in the tundish with channel induction heating.

Investigation of the fluid flow during the recoating process in additive manufacturing

2019 ◽  
Vol 26 (4) ◽  
pp. 605-613
Author(s):  
Andrei Kozhevnikov ◽  
Rudie P.J. Kunnen ◽  
Gregor E. van Baars ◽  
Herman J.H. Clercx
Keyword(s):  
Fluid Flow ◽  
Cfd Simulation ◽  
Flow Characteristics ◽  
Rectangular Cavity ◽  
Cavity Depth ◽  
Content Type ◽  
Loop Control ◽  
Computational Fluid Dynamics Cfd ◽  
Distance Sensor ◽  
Step Over

Purpose This paper aims to explore the fluid flow in the stereolithography process during the recoating step. The understanding of the flow dynamics can be used as an input for an active control of the resin surface height map. The recoating over a rectangular cavity has been considered to investigate the influence of the cavity depth on the resin surface height map. Design/methodology/approach Two-dimensional numerical simulations have been used to obtain the flow characteristics as function of the cavity depth. An experimental setup, which mimics the recoating process in the stereolithography process, was used to verify the results of simulations and to test the suitability of the 2D model. The surface height profile along the centreline was measured by a confocal chromatic distance sensor and compared to the 2D numerical results. Findings By means of computational fluid dynamics (CFD) simulation, the flow in the cavity and the free-surface behaviour of the resin was explained for different cavity depths and confirmed by experiments. Research limitations/implications The study is focused only on the cavity depth variation to show feasibility and suitability of the presented CFD model and the proposed analytical expression to estimate the layer thickness. Practical implications The proposed approach can serve as a tool for designing the closed-loop control for the recoating system in the next generation of stereolithography equipment. Originality/value In the present work, the fluid flow behaviour, a source of significant imperfection in the recoating process, has been investigated during the recoating step over a rectangular cavity.

Fluid Flow Characteristics for Partially-Confined Compact Plain-Plate-Fin Heat Sinks

2005 ◽  
Author(s):  
M. P. Wang ◽  
T. Y. Wu ◽  
J. T. Horng ◽  
C. Y. Lee ◽  
Y. H. Hung
Keyword(s):  
Experimental Data ◽  
Fluid Flow ◽  
Pressure Drop ◽  
Heat Sink ◽  
Flow Behavior ◽  
Flow Characteristics ◽  
Heat Sinks ◽  
Experimental Investigations ◽  
Channel Height ◽  
Fluid Flow Characteristics

A series of experimental investigations with a stringent measurement method on the study of the fluid flow behavior for confined compact heat sinks in forced convection have been successfully conducted. In the present study, a theoretical model to effectively predict the velocity and pressure drop for partially-confined heat sinks has been successfully developed. The air velocities flowing into heat sink Us through side bypass U1 and top bypass U2 for various 0.47<H/Hc<1 ratios are evaluated, where H/Hc is the ratio of the heat sink height to channel height. The maximum and average deviations of the velocities predicted by the present model from the experimental data are less than 20.31% and 13.13%, respectively, for confined compact heat sinks. Besides, the results show a good agreement between the predicted results and the experimental data of the pressure drop for the cases of H/Hc = 1. Nevertheless, the relative deviation of the predictions from the experimental data becomes more significant with decreasing H/Hc ratio, i.e., increasing the top bypass of confined compact heat sink. A new modified correlation of pressure drop including the H/Hc effect is presented. The maximum and average deviations of the results predicted by the new correlation from the experimental data are 14.48% and 7.72%, respectively.

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