scholarly journals Three-dimensional computational fluid dynamics analysis of an electric submerged arc furnace

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
K. Karalis ◽  
N. Karalis ◽  
N. Karkalos ◽  
Ν. Ntallis ◽  
G. S. E. Antipas ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Electrical Conductivity ◽  
Computational Fluid Dynamics ◽  
Three Dimensional ◽  
Decisive Role ◽  
Arc Furnace ◽  
Computational Fluid Dynamics Analysis ◽  
Cfd Method ◽  
Submerged Arc Furnace

AbstractA computational fluid dynamics (CFD) method is proposed to analyze the operation of a submerged electric arc furnace (SAF) used in ferronickel production. A three-dimensional mathematical model was used for the time-dependent solution of the fluid flow, heat transfer and electromagnetic phenomena. The slag's physical properties, which play a crucial role in the SAF operation, were previously determined using classical molecular dynamics simulations and empirical relationships. The analysis revealed that the main slag properties affecting SAF operation are density, viscosity and electrical conductivity—the latter two being mutually dependent. The high electrical conductivity values of the slag favor melting via the high Joule heat produced within the slag region. Calculation of the dimensionless Péclet and Reynolds numbers revealed that the slag velocities play a decisive role in heat transfer and further indicate that the slag flow is laminar. The average slag velocity calculated 0.0001 m/s with maxima in the vicinity of the electrodes.

scholarly journals Three-dimensional Computational Fluid Dynamics Analysis of an Electric Submerged Arc Furnace

2021 ◽  
Author(s):  
Konstantinos Karalis ◽  
Nikolaos Karalis ◽  
Nikolaos Karkalos ◽  
Georgios S.E. Antipas ◽  
Anthimos Xenidis
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Electrical Conductivity ◽  
Computational Fluid Dynamics ◽  
Three Dimensional ◽  
Decisive Role ◽  
Arc Furnace ◽  
Computational Fluid Dynamics Analysis ◽  
Cfd Method ◽  
Submerged Arc Furnace

Abstract A computational fluid dynamics (CFD) method is proposed for the analysis of the operation of a submerged electric arc furnace (EAF) used in the ferronickel production. The three-dimensional mathematical model was initiated for the time dependent solution of the fluid flow, heat transfer and electromagnetic phenomena. The physical properties of the slag, which has crucial role in the EAF operation were previously determined using classical molecular dynamics simulations and empirical relationships. The analysis revealed that the main slag properties affecting the EAF operation are the density, viscosity and electrical conductivity – the latter two being mutually dependent. The high electrical conductivity values of the slag favors melting via the high Joule heat produced within the slag region. Calculation of the dimensionless Péclet and Reynolds numbers revealed that the slag velocities play a decisive role in heat transfer and further indicate that the slag flow is laminar. The average slag velocity calculated 0.0001 m/s with maxima in the vicinity of the electrodes.

scholarly journals Computational fluid dynamics analysis of a three-dimensional electric submerged arc furnaceoperation

2020 ◽  
Author(s):  
Konstantinos Karalis ◽  
Nikolaos Karalis ◽  
Nikolaos Karkalos ◽  
Georgios S.E. Antipas ◽  
Antimos Xenidis
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Electrical Conductivity ◽  
Computational Fluid Dynamics ◽  
Three Dimensional ◽  
Decisive Role ◽  
Computational Fluid Dynamics Analysis ◽  
Slag Properties ◽  
Cfd Method ◽  
Dynamics Simulations

A computational fluid dynamics (CFD) method is proposed for the analysis of the operation of a submerged electric arc furnace (EAF) used in the ferronickel production. The three-dimensional mathematical model was initiated for the time dependent solution of the fluid flow, heat transfer and electromagnetic phenomena. The physical properties of the slag, which has crucial role in the EAF operation were determined using classical molecular dynamics simulations and empirical relationships. The analysis revealed that the main slag properties affecting the EAF operation are the density, viscosity and electrical conductivity – the latter two being mutually dependent. The high electrical conductivity values of the slag favors melting via the high Joule heat produced within the slag region. Calculation of the dimensionless Péclet and Reynolds numbers revealed that the slag velocities play a decisive role in heat transfer and further indicate that the slag flow is laminar. The average slag velocity calculated 0.0001 m/s with maxima in the vicinity of the electrodes.

Development and Validation of a Three-Dimensional Computational Fluid Dynamics Analysis for Journal Bearings Considering Cavitation and Conjugate Heat Transfer

2015 ◽  
Vol 137 (12) ◽  
Author(s):  
Yin Song ◽  
Chun-wei Gu
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Conjugate Heat Transfer ◽  
Three Dimensional ◽  
Journal Bearings ◽  
Cfd Analysis ◽  
Cavitation Model ◽  
Accurate Analysis ◽  
Cfd Method

Computational fluid dynamics (CFD) analysis, which solves the full three-dimensional (3D) Navier–Stokes equations, has been recognized as having promise in providing a more detailed and accurate analysis for oil-film journal bearings than the traditional Reynolds analysis, although there are still challenging issues requiring further investigation, such as the modeling of cavitation and the modeling of conjugate heat transfer effects in the CFD analysis of bearings. In this paper, a 3D CFD method for the analysis of journal bearings considering the above two effects has been developed; it employs three different cavitation models, including the Half-Sommerfeld model, a vaporous cavitation model, and a gaseous cavitation model. The method has been used to analyze a two-groove journal bearing and the results are validated with experimental measurements and the traditional Reynolds solutions. It is found that the CFD method which considers the conjugate heat transfer and employs the gaseous cavitation model gives better predictions of both bearing load and temperature than either the traditional Reynolds solution or CFD with other cavitation models. The CFD results also show strong recirculation of the fresh oil in the grooves, which has been neglected in the traditional Reynolds solution. The above results show conclusively that the present 3D CFD method considering the conjugate heat transfer and employing the gaseous cavitation model provides an efficient tool for more detailed and accurate analysis for bearing performance.

scholarly journals Airflow inside the nasal cavity: visualization using computational fluid dynamics

2010 ◽  
Vol 4 (4) ◽  
pp. 657-661 ◽  
Author(s):  
Mohammed Zubair ◽  
Vizy Nazira Riazuddin ◽  
Mohammed Zulkifly Abdullah ◽  
Rushdan Ismail ◽  
Ibrahim Lutfi Shuaib ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Nasal Cavity ◽  
Three Dimensional ◽  
Clinical Importance ◽  
Navier Stokes ◽  
Tomographic Images ◽  
Computed Tomographic ◽  
Continuity Equations ◽  
Cfd Method

Abstract Background: It is of clinical importance to examine the nasal cavity pre-operatively on surgical treatments. However, there is no simple and easy way to measure airflow in the nasal cavity. Objectives: Visualize the flow features inside the nasal cavity using computational fluid dynamics (CFD) method, and study the effect of different breathing rates on nasal function. Method: A three-dimensional nasal cavity model was reconstructed based on computed tomographic images of a healthy Malaysian adult nose. Navier-Stokes and continuity equations for steady airflow were solved numerically to examine the inspiratory nasal flow. Results: The flow resistance obtained varied from 0.026 to 0.124 Pa.s/mL at flow-rate from 7.5 L/min to 40 L/min. Flow rates by breathing had significant influence on airflow velocity and wall shear-stress in the vestibule and nasal valve region. Conclusion: Airflow simulations based on CFD is most useful for better understanding of flow phenomenon inside the nasal cavity.

scholarly journals Computational fluid dynamics analysis of the hydraulic (filtration) efficiency of a residential swimming pool

2018 ◽  
Vol 16 (5) ◽  
pp. 750-761 ◽  
Author(s):  
J. Zhang ◽  
N. Sinha ◽  
M. Ross ◽  
A. E. Tejada-Martínez
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Residence Time ◽  
Dead Zone ◽  
Three Dimensional ◽  
Circulation Pattern ◽  
Filtration Efficiency ◽  
Swimming Pools ◽  
Hydraulic Efficiency ◽  
Computational Fluid Dynamics Analysis

Abstract Hydraulic or filtration efficiency of residential swimming pools, quantified in terms of residence time characteristics, is critical to disinfection and thus important to public health. In this study, a three-dimensional computational fluid dynamics model together with Eulerian and Lagrangian-based techniques are used for investigating the residence time characteristics of a passive tracer and particles in the water, representative of chemicals and pathogens, respectively. The flow pattern in the pool is found to be characterized by dead zone regions where water constituents may be retained for extended periods of times, thereby potentially decreasing the pool hydraulic efficiency. Two return-jet configurations are studied in order to understand the effect of return-jet location and intensity on the hydraulic efficiency of the pool. A two-jet configuration is found to perform on par with a three-jet configuration in removing dissolved constituents but the former is more efficient than the latter in removing or flushing particles. The latter result suggests that return-jet location and associated flow circulation pattern have an important impact on hydraulic efficiency. Thus return-jet configuration should be incorporated as a key parameter in the design of swimming pools complementing current design standards.

Computational Fluid Dynamics Analysis of Aerodynamics and Impingement Heat Transfer From Hexagonal Arrays of Multiple Dual-Swirling Impinging Flame Jets

2020 ◽  
Vol 142 (8) ◽  
Author(s):  
Parampreet Singh ◽  
Ratna Kishore Velamati ◽  
Subhash Chander
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Target Surface ◽  
Separation Distance ◽  
Release Mechanism ◽  
Hexagonal Array ◽  
Array Configuration ◽  
Computational Fluid Dynamics Analysis ◽  
Impinging Flames

Abstract Radiative furnaces pose significant thermal inertia and single impinging flames have been observed to cause occurrence of hotspots on the target surface. Multiple burners arranged in suitable array configuration represent one of the plausible solutions for more uniform heat transfer. In this study, computational fluid dynamics (CFD) simulations have been carried out for multiple swirling impinging flames arranged in a hexagonal array configuration. The turbulence chemistry interactions in the flame field are solved numerically using renormalization group (RNG) based k–ε/eddy dissipation model (EDM) framework. Comparison of co-and-counter-swirling configurations has been studied for interactions and spent gas release mechanism. Multiple swirling impinging flames undergo strong interactions resulting in distortions of recirculation zones (RCZ) for all the surrounding except central flame. Co-swirling flames result in development of higher turbulence in the interaction regions as compared to counter-swirl case. Results indicate that some flames in counter-swirl case are underutilized due to the fluid dynamics developed in the system and co-swirling hexagonal array configuration is a better arrangement for effective heating of target surface. Effect of interjet spacing (S/Dh = 5, 7, and 9) and separation distance (H/Dh = 3, 5, 7, and 9) studied for co-swirl case revealed that peak heat fluxes decreased with increasing interjet spacing and separation distance. Central flame represented a region of low heat flux and this region has been noticed to expand in size for increasing interjet spacings. Suppression of central flame has been observed to be maximum for minimum separation distance.

scholarly journals Enhancement of Film Boiling Characteristics Using Computational Fluid Dynamics Analysis for Moving Steel Plate

2020 ◽  
Vol 6 (2) ◽  
pp. 33-42
Author(s):  
Ritu Raj ◽  
Vardan Singh Nayak
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Steel Plate ◽  
Saturation Temperature ◽  
Film Boiling ◽  
Dynamics Analysis ◽  
Fluid Temperature ◽  
Plate Surface ◽  
Computational Fluid Dynamics Analysis

Present study provides guidelines and recommendations for solving film boiling problems in steel plate production, where the surface temperature of steel plate is much higher than the saturation temperature of the liquid in contact with the plate surface and the entire steel plate surface is immersed in water. Due to the boiling mass exchange occurring at the vapor liquid interface bubbles of steam are periodically produced and emitted upward such a regime is known as film boiling. A computational fluid dynamics analysis of steel plate using VOF multiphase model moving at different velocity i.e. 0.1 to 0.5 m/sec. the volume of fraction for vapor phase have been obtained for different time interval, the generation of bubbles starts moving upwards after 0.05 sec, as time goes the formation of vapor bubbles generate and collapse more rapidly because the thermal boundary is very thin and the fluid temperature around the bubbles almost equal to the saturation temperature. The thermal properties of the steel plate are implicit to be constant with temperature for convenience because the present study is focused on the boiling heat transfer on the steel plate. The size of element is set as 0.1 mm to generate mesh and quad-4 rectangular elements used are which is a rectangular in shape with four nodes on each element are applied for the analysis. Results show that that the 37.98% of Convective heat transfer coefficient of mixture is increased and 13.1% of temperature drop has been observed with 40.67% of heat flux increased for the steel plate moving at 0.1 m/sec.

Forced Convection Computational Fluid Dynamics Analysis of Architected and Three-Dimensional Printable Heat Sinks Based on Triply Periodic Minimal Surfaces

2020 ◽  
Vol 13 (2) ◽  
Author(s):  
Oraib Al-Ketan ◽  
Mohamed Ali ◽  
Mohamad Khalil ◽  
Reza Rowshan ◽  
Kamran A. Khan ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Heat Transfer Coefficient ◽  
Minimal Surfaces ◽  
Heat Sink ◽  
Three Dimensional ◽  
Heat Sinks ◽  
Triply Periodic Minimal Surfaces ◽  
Triply Periodic

Abstract The drive for small and compact electronic components with higher processing capabilities is limited by their ability to dissipate the associated heat generated during operations, and hence, more advanced heat sink designs are required. Recently, the emergence of additive manufacturing techniques facilitated the fabrication of complex structures and overcame the limitation of traditional techniques such as milling, drilling, and casting. Therefore, complex heat sink designs are now easily realizable. In this study, we propose a design procedure for mathematically realizable architected heat sinks and investigate their performance using the computational fluid dynamics (CFD) approach. The proposed heat sinks are mathematically designed with topologies based on triply periodic minimal surfaces (TPMSs). Three-dimensional CFD models are developed using the starccm+ platform for uniform heat sinks and topologically graded heat sinks to study the heat transfer performance in forced convection domains. The overall heat transfer coefficient, surface temperature, and pressure drop versus the input heat sources as well as the Reynolds number are used to evaluate the heat sink performance. Moreover, temperature contours and velocity streamlines were examined to analyze the fluid flow behavior within the heat sinks. Results showed that the tortuosity and channel complexity of the Diamond solid-networks heat sink result in a 32% increase in convective heat transfer coefficient compared with the Gyroid solid-network heat sink which has the comparable surface area under the examined flow conditions. This increase is at the expense of increased pressure drops which increases by the same percentage. In addition, it was found that expanding channel size along flow direction using the porosity grading approach results in significant pressure drop (27.6%), while the corresponding drop in convective heat transfer is less significant (15.7%). These results show the importance of employing functional grading in the design of heat sinks. Also, the manufacturability of the proposed designs was assessed using computerized tomography (CT) scan and scanning electron microscopy (SEM) imaging performed on metallic samples fabricated using powder bed fusion techniques. A visible number of internal manufacturing defects can affect the performance of the proposed heat sinks.

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