Numerical investigation of in-mold electromagnetic stirring process for fluid flow and solidification

2017 ◽  
Vol 36 (4) ◽  
pp. 1106-1119 ◽  
Author(s):  
Ambrish Maurya ◽  
Pradeep Kumar Jha
Keyword(s):  
Finite Element ◽  
Fluid Flow ◽  
Continuous Casting ◽  
Finite Volume ◽  
Flow Behavior ◽  
Hybrid Approach ◽  
Liquid Core ◽  
Electromagnetic Stirring ◽  
Solid Shell ◽  
Content Type

Purpose The purpose of present investigation is to analyze the in-mold electromagnetic stirring (M-EMS) process and the effect of stirrer frequency on fluid flow and solidification in a continuous casting billet caster mold. Design/methodology/approach A hybrid approach involving finite element and finite volume method has been used for the study. Finite element model is used to calculate time variable magnetic field, which is further coupled with fluid flow and solidification equations for magneto-hydrodynamic analysis with finite volume model. Findings Results show that though superheat given to steel before its entry into the mold is quickly removed, solid shell formation is delayed by the use of M-EMS. Final solid shell thickness, however, is slightly reduced. Increase in frequency is found to increase the magnetic flux density and tangential velocity of liquid steel and decrease in diameter of liquid core. Practical implications The work is of great industrial relevance. The model may be used to design industrial setup of in-mold electromagnetic stirrer and process could be analyzed and optimized numerically. Originality/value The paper evaluates the influence of M-EMS and its frequency on solidification and flow behavior in the continuous casting mold. The iso-surface temperatures from pouring temperature to liquidus temperature inside the mold have been shown. The findings may be useful for the steelmakers to reduce the defect in continuous casting.

Experimental and numerical studies on flow behavior of surface defects in the heavy rail rolling

2018 ◽  
Vol 35 (3) ◽  
pp. 1279-1300
Author(s):  
Chenggang Pan ◽  
Zizheng Ding ◽  
Qingming Chang ◽  
Jialin Zhou
Keyword(s):  
Finite Element ◽  
Continuous Casting ◽  
Surface Defect ◽  
Surface Defects ◽  
Flow Behavior ◽  
Modified Model ◽  
Content Type ◽  
Explicit Dynamic ◽  
Heavy Rail ◽  
Good Agreement

Purpose Surface defects are often present on the surface of continuous casting slabs and rolled products. A lot of surface defects of hot rolled products are inherited from initial defects on continuous casting slabs. This work aims to trace the original surface defect during the whole heavy rail rolling and avoid black line surface defect that appears on the surface of heavy rail finial product. Design/methodology/approach Artificial round hole-shaped surface defects on the surface of continuous casting slab during the hot rolling of 60 kg/m heavy rail are analyzed experimentally and by means of explicit dynamic finite element method (FEM) and modified model rebuilding method. Findings The calculated results of surface defect locations of heavy rail finial product are in good agreement with the experimental ones. It is shown that the explicit dynamic FEM and modified model rebuilding method can be used effectively to predict the flow behavior of surface defects in the hot rolling of 60 kg/m heavy rail. Originality/value The three-dimensional finite element model for whole heavy rail rolling is built using explicit dynamic code and modified model rebuilding method. Flow behavior of black lines is studied in the 60-kg/m heavy rail rolling. The simulation results of six typical points are in good agreement with the experimental results.

scholarly journals Fluid Flow Behavior in Submerged Entry Nozzle of Continuous Casting

2007 ◽  
Vol 47 (6) ◽  
pp. 840-846 ◽  
Author(s):  
Toru Kato ◽  
Masashi Hara ◽  
Akifumi Muto ◽  
Sei Hiraki ◽  
Masayuki Kawamoto
Keyword(s):  
Fluid Flow ◽  
Continuous Casting ◽  
Flow Behavior ◽  
Submerged Entry Nozzle

scholarly journals Single point incremental forming simulation with adaptive remeshing technique using solid-shell elements

2016 ◽  
Vol 33 (5) ◽  
pp. 1388-1421 ◽  
Author(s):  
José I.V. Sena ◽  
Cedric Lequesne ◽  
L Duchene ◽  
Anne-Marie Habraken ◽  
Robertt A.F. Valente ◽  
...  
Keyword(s):  
Finite Element ◽  
Incremental Forming ◽  
Single Point ◽  
Nonlinear Material ◽  
Single Point Incremental Forming ◽  
Solid Shell ◽  
Contact Conditions ◽  
Adaptive Remeshing ◽  
Content Type ◽  
Shell Elements

Purpose – Numerical simulation of the single point incremental forming (SPIF) processes can be very demanding and time consuming due to the constantly changing contact conditions between the tool and the sheet surface, as well as the nonlinear material behaviour combined with non-monotonic strain paths. The purpose of this paper is to propose an adaptive remeshing technique implemented in the in-house implicit finite element code LAGAMINE, to reduce the simulation time. This remeshing technique automatically refines only a portion of the sheet mesh in vicinity of the tool, therefore following the tool motion. As a result, refined meshes are avoided and consequently the total CPU time can be drastically reduced. Design/methodology/approach – SPIF is a dieless manufacturing process in which a sheet is deformed by using a tool with a spherical tip. This dieless feature makes the process appropriate for rapid-prototyping and allows for an innovative possibility to reduce overall costs for small batches, since the process can be performed in a rapid and economic way without expensive tooling. As a consequence, research interest related to SPIF process has been growing over the last years. Findings – In this work, the proposed automatic refinement technique is applied within a reduced enhanced solid-shell framework to further improve numerical efficiency. In this sense, the use of a hexahedral finite element allows the possibility to use general 3D constitutive laws. Additionally, a direct consideration of thickness variations, double-sided contact conditions and evaluation of all components of the stress field are available with solid-shell and not with shell elements. Additionally, validations by means of benchmarks are carried out, with comparisons against experimental results. Originality/value – It is worth noting that no previous work has been carried out using remeshing strategies combined with hexahedral elements in order to improve the computational efficiency resorting to an implicit scheme, which makes this work innovative. Finally, it has been shown that it is possible to perform accurate and efficient finite element simulations of SPIF process, resorting to implicit analysis and continuum elements. This is definitively a step-forward on the state-of-art in this field.

scholarly journals A hybrid finite volume/finite element method for shallow water waves by static deformation on seabeds

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Alia Al-Ghosoun ◽  
Ashraf S. Osman ◽  
Mohammed Seaid
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Free Surface ◽  
Shallow Water ◽  
Finite Volume ◽  
Second Order ◽  
Static Deformation ◽  
Wave Runup ◽  
Content Type ◽  
Element Method

Purpose The purpose of this study is twofold: first, to derive a consistent model free-surface runup flow problems over deformable beds. The authors couple the nonlinear one-dimensional shallow water equations, including friction terms for the water free-surface and the two-dimensional second-order solid elastostatic equations for the bed deformation. Second, to develop a robust hybrid finite element/finite volume method for solving free-surface runup flow problems over deformable beds. The authors combine the finite volume for free-surface flows and the finite element method for bed elasticity. Design/methodology/approach The authors propose a new model for wave runup by static deformation on seabeds. The model consists of the depth-averaged shallow water system for the water free-surface coupled to the second-order elastostatic formulation for the bed deformation. At the interface between the water flow and the seabed, transfer conditions are implemented. Here, hydrostatic pressure and friction forces are considered for the elastostatic equations, whereas bathymetric forces are accounted for in the shallow water equations. As numerical solvers, the authors propose a well-balanced finite volume method for the flow system and a stabilized finite element method for elastostatics. Findings The developed coupled depth-averaged shallow water system and second-order solid elastostatic system is well suited for modeling wave runup by deformation on seabeds. The derived coupling conditions at the interface between the water flow and the bed topography resolve well the condition transfer between the two systems. The proposed hybrid finite volume element method is accurate and efficient for this class of models. The novel technique used for wet/dry treatment accurately captures the moving fronts in the computational domain without generating nonphysical oscillations. The presented numerical results demonstrate the high performance of the proposed methods. Originality/value Enhancing modeling and computations for wave runup problems is at an early stage in the literature, and it is a new and exciting area of research. To the best of our knowledge, solving wave runup problems by static deformation on seabeds using a hybrid finite volume element method is presented for the first time. The results of this research study, and the research methodologies, will have an important influence on a range of other scientists carrying out research in related fields.

Two-phase analysis of interface level fluctuation in continuous casting mold with electromagnetic stirring

2018 ◽  
Vol 28 (9) ◽  
pp. 2036-2051 ◽  
Author(s):  
Ambrish Maurya ◽  
Pradeep Kumar Jha
Keyword(s):  
Electromagnetic Field ◽  
Fluid Flow ◽  
Mold Flux ◽  
Electromagnetic Stirring ◽  
Level Fluctuation ◽  
Stability Criteria ◽  
Two Phase ◽  
Content Type ◽  
Coupled Numerical Model ◽  
Phase Fluid

Purpose This investigation aims to analyze the steel-flux interface level fluctuation because of electromagnetic stirring and its process parameters in a continuous casting billet mold. Design/methodology/approach An un-coupled numerical model for electromagnetic field generation and a coupled numerical model of electromagnetic field and two-phase fluid flow have been developed. The two-phase fluid flow has been modeled using volume of fluid method, in which externally generated time-varying electromagnetic field is coupled and analyzed using magnetohydrodynamic method. Top surface standing wave stability criteria are used to study the criticality of interface stability. Findings Results show that application electromagnetic field for stirring increases the interface level fluctuation, specifically at the mold corners and near the submerged entry nozzle. The increase in current intensity and stirrer width barely affect the interface level. However, interface level fluctuation increases considerably with increase in frequency. Using stability criteria, it is found that at 20 Hz frequency, the ratio of height to wavelength of interface wave increases much above the critical value. The iso-surface of the interface level shows that at 20 Hz frequency, mold flux gets entrapped into the liquid steel. Practical implications The model may be used during optimization of in-mold electromagnetic stirrer to avoid mold flux entrapment and control the cast quality. Originality/value The study of mold level fluctuation in the presence of in-mold electromagnetic stirrer has rarely been reported. The criticality of stirrer process parameters on level fluctuation has not been yet reported. This study lacks in experimental validation; however, the findings will be much useful for the steelmakers to reduce the casting defects.

INTERSTITIAL FLUID FLOW BEHAVIOR IN OSTEON WALL UNDER NON-AXISYMMETRIC LOADING: A FINITE ELEMENT STUDY

2018 ◽  
Vol 18 (07) ◽  
pp. 1840007
Author(s):  
XIAO-GANG WU ◽  
TENG ZHAO ◽  
XIAO-HONG WU ◽  
JIANG-LAN XIE ◽  
KUI-JUN CHEN ◽  
...  
Keyword(s):  
Finite Element ◽  
Fluid Flow ◽  
Axial Compression ◽  
Flow Behavior ◽  
Pressure Amplitude ◽  
Interstitial Fluid Flow ◽  
Compression Loading ◽  
Velocity Amplitude ◽  
Bone Fluid Flow ◽  
Loading Case

Physiological loads are non-axisymmetric and can lead to interstitial bone fluid flow, particularly in osteon. According to research, interstitial bone fluid flow plays a key role in bone mechanotransduction. To evaluate the poroelastic responses of a non-axisymmetric loaded osteon, this paper presents a finite element osteon model that is bulit by using the Comsol Multiphysics software. Obtained results show that under the same loading amplitude, the generated pressure and velocity amplitudes in the axial compression loading case are the largest, followed by that in the compressive bending loading, and smallest in the bending case. Moreover, the induced pressure and velocity amplitudes in axial compression loading exhibit an axial symmetrical distribution and axial centrosymmetric distribution in the compressive bending. In the bend loading case, the pressure amplitude presents an antisymmetric distribution, but the velocity amplitude is axially symmetrically distributed. Therefore, the distributions of pressure and velocity are definitely affected by load types, which lead to different bone fluid stimuli in mechanotransduction.

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