• Transactions of Materials Processing
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• v.4 no.1
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• pp.69-78
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• 1995

The arbitrary Lagrangian-Eulerian(ALE) finite element analysis is applied to the axisymmetric hot extrusion through continuous dies. In order to simulate hot forming problems, an ALE scheme for temperature analysis is proposed. The computed results are compared with experimental results as with those by pure Lagrangian method. In the present study mesh control is accomplished by the use of isoparametric mapping of quadrilaterals.

• Journal of the Chungcheong Mathematical Society
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• v.26 no.3
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• pp.591-599
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• 2013

A large number of sequences of polynomials and numbers have arisen in mathematics. Some of them, for example, Bernoulli polynomials and numbers, have been investigated deeply and widely. Here we aim at presenting certain interesting and (potentially) useful identities involving mainly in the second-order Eulerian numbers and Stirling polynomials, which seem to have not been given so much attention.

• Interaction and multiscale mechanics
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• v.5 no.3
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• pp.287-318
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• 2012

We apply a partitioned-solution (iterative-staggered) coupling method based on a fixed Eulerian mesh with the level set function to a large-deformation fluid-structure interaction (FSI) problem where a large-deformable thin structure moves in a high-speed flow field, as an airbag does during deployment. This method combines advanced fluid and structure solvers-specifically, the constrained interpolation profile finite element method (CIP-FEM) for fluid Eulerian mesh and large-deformable structural elements for Lagrangian structural mesh. We express the large-deformable interface as a zero isosurface by the level set function, and introduce virtual nodes with level sets and structural normal velocities to generate the level set function according to the large-deformable interfacial geometry and enforce the kinematic condition at the interface. The virtual nodes are located in the direction normal to the structural mesh. It is confirmed that application of the method to unfolded airbag deployment simulation shows the adequacy of the method.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.6 no.1
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• pp.1-15
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• 2002

Advection-dominated transport problems possess difficulties in the design of numerical methods for solving them. Because of the hyperbolic nature of advective transport, many characteristic numerical methods have been developed such as the classical characteristic method, the Eulerian-Lagrangian method, the transport diffusion method, the modified method of characteristics, the operator splitting method, the Eulerian-Lagrangian localized adjoint method, the characteristic mixed method, and the Eulerian-Lagrangian mixed discontinuous method. In this paper relationships among these characteristic methods are examined. In particular, we show that these sometimes diverse methods can be given a unified formulation. This paper focuses on characteristic finite element methods. Similar examination can be presented for characteristic finite difference methods.

• Transactions of Materials Processing
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• v.10 no.7
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• pp.579-583
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• 2001

Shape changes of a workpiece in an Eulerian Finite Element analysis for the steady state, three-roll-stand shape rolling are modelled. Although an Eulerian analysis has many advantages for the steady state rolling problems, it necessitates an assumption about the unknown shape of the control volume. In almost all cases, the assumed control volume does not match the final shape and the control volume should be updated. This update can be accomplished by performing a free surface correction. The final shape of a material point, which has a spherical shape at the inlet, can be also predicted by integrating a deformation gradient along a stream line. Analyses of three-roll-stand shape rolling are performed and the results are discussed in detail.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.328-331
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• 2001

Shape changes of a workpiece in an Eulerian Finite Element analysis for the steady state. three-roll-stand shape rolling are modelled. Although an Eulerian analysis has many advantages for the steady state rolling problems, it necessitates an assumption about the unknown shape of the control volume. In almost all cases. the assumed control volume does not match the final shape and the control volume should be updated. This update can be accomplished by performing a free surface correction. The final shape of a material point, which has a spherical shape at the inlet, can be also predicted by integrating a deformation gradient along a stream line. Analyses of three-roll-stand shape rolling is in detail examined.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.460-463
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• 2010

Ice accretion on aircraft surface can greatly impair the aerodynamic performance of aircraft. As an alternative to the traditional Lagrangian particle tracking approach, an Eulerian-based droplet impingement and ice accretion code for air flows containing water droplets was developed A CFD solver was also developed to solve the clean airflow. The results of present method were compared with experimental data and previous icing codes such as LEWICE and FENSAP-ICE and were confirmed to show good agreement each other in qualitative and quantitative ways.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.229-232
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• 2007

A numerical method for the moving boundary required in analysis of the combustion phenomenon of the solid propellant has been studied. The ghost cell extrapolation has been used in the Eulerian coordinate system. The Lagrangian method has been used in Non-Eulerian coordinate system. Results of the numerical analysis were verified by comparing to theoretical results of 1-D free-moving piston in the pipe.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.235-242
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• 2003

The solids and the fluids in porous media have a relative velocity to each other. Due to physically and chemically different material properties and their relative velocity, the behavior of saturated porous media is extremely complicated. Thus, in order to describe and clarify the deformation behavior of saturated porous media, constitutive models for deformation of porous media coupling several effects such as flow of the fluids or thermodynanical change need to be developed in frame of Arbitrary Lagrangian Eulerian (ALE) description. The aim of ALE formulations is to maximize the advantages of Lagrangian and Eulerian elements, and to minimize the disadvantages. Therefore, this method is appropriate for the analysis of porous media that are considered for the behavior of the solids and the fluids. In this work, governing equations of porous media based on ALE description are obtained from governing equations in frame of updated Lagrangian description. Then, weak forms of these equations are derived using arbitrary weighting functions.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.381-388
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• 2006

A porous medium is composed of solids, fluids, and gas which have different physical and chemical properties. In addition, these constituents have a relative velocity between each other. So far, in order to analyze porous media using finite element method, Lagrangian or Eulerian method has been used. However, the numerical analyses for porous media have a defect that the methods do not describe the movements of constituents. In this paper, numerical analysis for unsaturated porous media was performed in frame of ALE method which has advantages of Lagrangian and Eulerian. Namely, the Lagrangian description was used in solid phase, and the Eulerian description was used in fluid or gas phase in a porous medium Then the relationship between each other was controlled by the convective term in ALE method. Finally, the numerical results of ALE were compared with tile results of Lagrangian analysis.