scholarly journals Computer Simulation of the Solidification Process Including Air Gap Formation

2017 ◽  
Vol 17 (4) ◽  
pp. 147-150 ◽  
Author(s):  
T. Skrzypczak ◽  
E. Węgrzyn-Skrzypczak ◽  
L. Sowa
Keyword(s):  
Heat Transport ◽  
Dimensional Space ◽  
Solidification Process ◽  
Air Gap ◽  
Heat Conducting ◽  
Gap Formation ◽  
Solidification Model ◽  
Coefficient Of Thermal Conductivity ◽  
Equation Of Heat Conduction ◽  
The Mathematical Model

Abstract The paper presents an approach of numerical modelling of alloy solidification in permanent mold and transient heat transport between the casting and the mold in two-dimensional space. The gap of time-dependent width called "air gap", filled with heat conducting gaseous medium is included in the model. The coefficient of thermal conductivity of the gas filling the space between the casting and the mold is small enough to introduce significant thermal resistance into the heat transport process. The mathematical model of heat transport is based on the partial differential equation of heat conduction written independently for the solidifying region and the mold. Appropriate solidification model based on the latent heat of solidification is also included in the mathematical description. These equations are supplemented by appropriate initial and boundary conditions. The formation process of air gap depends on the thermal deformations of the mold and the casting. The numerical model is based on the finite element method (FEM) with independent spatial discretization of interacting regions. It results in multi-mesh problem because the considered regions are disconnected.

Conjugate Heat Transfer and Effects of Interfacial Heat Flux During the Solidification Process of Continuous Castings

2003 ◽  
Vol 125 (2) ◽  
pp. 339-348 ◽  
Author(s):  
M. Ruhul Amin ◽  
Nikhil L. Gawas
Keyword(s):  
Heat Transfer ◽  
Continuous Casting ◽  
Cooling Rate ◽  
Solidification Process ◽  
Air Gap ◽  
Gap Formation ◽  
Continuous Casting Mold ◽  
Withdrawal Velocity ◽  
Multiphase Fluid Flow ◽  
Multiphase Fluid

Multiphase fluid flow involving solidification is common in many industrial processes such as extrusion, continuous casting, drawing, etc. The present study concentrates on the study of air gap formation due to metal shrinkage on the interfacial heat transfer of a continuous casting mold. Enthalpy method was employed to model the solidification of continuously moving metal. The effect of basic process parameters mainly superheat, withdrawal velocity, mold cooling rate and the post mold cooling rate on the heat transfer was studied. The results of cases run with air gap formation were also compared with those without air gap formation to understand the phenomenon comprehensively. The current study shows that there exists a limiting value of Pe above which the effect of air gap formation on the overall heat transfer is negligible.

The Effect of Air Gap between Casting and Water-Cooled Mold on Interface Heat Transfer Coefficient

2017 ◽  
Vol 893 ◽  
pp. 174-180 ◽  
Author(s):  
Yi Dan Zeng ◽  
Qing Hu Yao ◽  
Xia Wang
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Solidification Process ◽  
Casting Process ◽  
Air Gap ◽  
Gap Formation ◽  
Interface Heat Transfer Coefficient ◽  
Interface Heat Transfer ◽  
Interface Heat

Water-cooled casting is a new casting process. It allows even large castings to solidify rapidly, thereby reducing segregation and grain refinement. It has drawn the attention of both domestic and foreign businesses. Heat transfer at the casting/water-cooled mold interface controls the cooling rate of the casting. During the solidification process, because of the contraction that takes place during casting, an air gap can form between the casting and the water-cooled mold. This air gap hinders heat transfer between the casting and the mold, leading to a rapid drop in the interface heat transfer coefficient (IHTC). The purpose of the present study was to assess the effects of the width of the air gap and the duration of gap formation on IHTC. During the experiment, the casting temperature curve was determined in the presence of the interface air gap, and then inverse calculation was performed using PROCAST software to determine the IHTC of casting/water-cooled mold. Results showed that, after the formation of the air gap, IHTC first exhibited a rapid decrease, followed by an increase and then another decrease; IHTC was found to decrease as gap width increased and as the duration of gap formation increased.

Numerical Simulation of Air Gap Formation in Water-Cooled Mold Casting

2014 ◽  
Vol 881-883 ◽  
pp. 1790-1794
Author(s):  
Hui Shu Zhang ◽  
Dong Ping Zhan ◽  
Bi Tao Deng ◽  
Li Jun Wang ◽  
Zhou Hua Jiang
Keyword(s):  
Ingot Mold ◽  
Steel Ingot ◽  
Solidification Process ◽  
Air Gap ◽  
The Other ◽  
Temperature Decrease ◽  
Gap Formation ◽  
Ingot Quality ◽  
Mold Casting ◽  
Produce Steel

While using water cooled mold to produce steel ingot, an air gap is generated between the ingot and the mold, which has an important influence on the ingot quality. The air gap formation law and its influence on the solidification process were calculated by used FE software Procast. It is shown that, air gap occurs in a few minutes after the solidification begins. In 75-100s later the gap reaches 0.2-0.5 mm and starts to influent the heat transport significantly, the rate of the temperature decrease becomes slower. When the solidification is finished, there is a lager gap on the two narrow surfaces than it on the other wide surfaces; and the gap on the two narrow surfaces is different. The air gap on the narrow surface close to the sprue has a width of 12-20 mm; on the other narrow surface away from the sprue has a width of 4-13 mm. The biggest gap on the two wide surfaces has a size about 6.5mm. For the air gap is formatted between the ingot shell and the ingot mold, the solidification time is 50% longer than that of without air gap.

scholarly journals Heat Transfer Coefficient Determination in a Gravity Die Casting Process with Local Air Gap Formation and Contact Pressure Using Experimental Evaluation and Numerical Simulation

2021 ◽  
Author(s):  
T. Vossel ◽  
N. Wolff ◽  
B. Pustal ◽  
A. Bührig-Polaczek ◽  
M. Ahmadein
Keyword(s):  
Heat Transfer ◽  
Contact Pressure ◽  
Local Heat Transfer ◽  
Casting Process ◽  
Local Heat ◽  
Air Gap ◽  
Gap Formation ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Die Casting Process

AbstractAnticipating the processes and parameters involved for accomplishing a sound metal casting requires an in-depth understanding of the underlying behaviors characterizing a liquid melt solidifying inside its mold. Heat balance represents a major factor in describing the thermal conditions in a casting process and one of its main influences is the heat transfer between the casting and its surroundings. Local heat transfer coefficients describe how well heat can be transferred from one body or material to another. This paper will discuss the estimation of these coefficients in a gravity die casting process with local air gap formation and heat shrinkage induced contact pressure. Both an experimental evaluation and a numerical modeling for a solidification simulation will be performed as two means of investigating the local heat transfer coefficients and their local differences for regions with air gap formation or contact pressure when casting A356 (AlSi7Mg0.3).

Mould-taper asymptotics and air gap formation in continuous casting

2015 ◽  
Vol 268 ◽  
pp. 1122-1139 ◽  
Author(s):  
B.J. Florio ◽  
M. Vynnycky ◽  
S.L. Mitchell ◽  
S.B.G. O’Brien
Keyword(s):  
Continuous Casting ◽  
Air Gap ◽  
Gap Formation

3D Thermo-Mechanical Modelling of Wheel and Belt Continuous Casting

2011 ◽  
Vol 693 ◽  
pp. 235-244 ◽  
Author(s):  
John F. Grandfield ◽  
Sébastien Dablement ◽  
Hallvard Gustav Fjær ◽  
Dag Mortensen ◽  
Michael Lee ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Continuous Casting ◽  
Three Dimensional ◽  
Casting Process ◽  
Liquid Pool ◽  
Air Gap ◽  
Temperature Measurements ◽  
Heat Extraction ◽  
Gap Formation ◽  
Solidification Defects

Wire rod is produced by hot-rolling a bar of metal coming from a wheel/belt continuous casting process. This kind of process, e.g. Properzi, is an elaborate process in which the molten metal is poured in a cooled rotating mould formed by the groove of a wheel and closed by a belt. In order to better understand the heat transfer phenomenon and solidified bar characteristics, depending on process parameters a three dimensional thermo-mechanical model has been developed. The model, based on the finite-element method, calculates the heat transfer coefficient of the air gap at the metal-mould interface as a function of the size of the gap determined by the bar contraction and wheel and belt thermal deformations. The air gap formation due to metal shrinkage and mould deformation is the main factor which determines the heat extraction. Wheel temperature measurements with thermocouple and belt temperature measurements with an infrared system were carried out to verify model results. Attempts were also made to measure a liquid pool profile using doping with copper rich alloy. The model shows the effect of the casting temperature and the rotation speed on the air gap formation and resulting temperature and stress fields. The model can be applied to issues such as maximising wheel and belt life and minimising solidification defects.

scholarly journals Comparison of numerical simulation models for predicting temperature in solidification analysis with reference to air gap formation

2004 ◽  
Vol 17 (5) ◽  
pp. 295-310 ◽  
Author(s):  
J. Kron ◽  
M. Bellet ◽  
A. Ludwig ◽  
B. Pustal ◽  
J. Wendt ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Simulation Models ◽  
Air Gap ◽  
Gap Formation

Numerical modeling of solidification process taking into account the effect of air gap

2018 ◽  
Vol 321 ◽  
pp. 768-779 ◽  
Author(s):  
Tomasz Skrzypczak ◽  
Ewa Węgrzyn-Skrzypczak ◽  
Leszek Sowa
Keyword(s):  
Numerical Modeling ◽  
Solidification Process ◽  
Air Gap
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