Shuhei Matsuzawa

Numerical Analysis of Cold Crucible Induction Melting Employing FEM and MPS Method

This paper proposes a coupled method of 3-D finite element method (FEM) and moving particle semi-implicit (MPS) method for the analysis of cold crucible induction melting. In this method, the magnetic field is calculated by FEM and the fluid motion equation of the molten metal and the thermal distribution in the molten metal are calculated by the MPS method. In this paper, the phase transformation of the metal is not considered. The effectiveness of this method is verified through the analysis of the molten metal behavior in the crucible.

Validation of Meshless Method Based on Weighted Least Square Method for Simulating Electromagnetic Levitation

Electromagnetic levitation is a kind of magnetohydrodynamic phenomena, which is used for measuring the thermophysical properties of pure metals under high temperature. However, this phenomenon is complicated, and detailed mechanisms have not been clarified yet. This paper proposes the meshless method based on weighted least square method for the analysis of electromagnetic levitation. In this method, the fluid motion equation and the magnetic field equation are weakly coupled. The effectiveness of this method is verified through the analysis of the molten metal behavior.

Numerical Analysis of Behavior of High-Viscosity Electromagnetic Fluid Using a Coupled Method of Particle Method and FEM

Electromagnetic fluid, which is usually a suspension of extremely fine particles of metal in carrier fluid, shows unique behaviors such as large deformation or a change of material properties in electromagnetic field. This paper deals with elongation and sharpening of electromagnetic fluid with extremely high viscosity in electrostatic field. This behavior is very difficult to calculate with the finite-element model (FEM) because it includes intensive deformation and a large change of interfacial surface of fluid. Therefore, we propose an improved 3-D coupled method of FEM and moving particle semi-implicit (MPS). Electrostatic field analysis with the FEM and fluid analysis with MPS is weakly coupled. This paper implicitly calculates viscous terms in Navier-Stokes equations and succeeds in accurately calculating deformation of high-viscosity electromagnetic fluid.

Numerical Analysis of Negative Ion by Electrostatic Atomization Employing FEM and MPS Method

This paper proposes a coupled method of 3-D finite element method (FEM) and Moving Particle Semi-implicit (MPS) method for the analysis of a negative ion that is produced by electrostatic atomization. In this method, the electric field is calculated by FEM and the fluid motion equation of a drop of water is calculated by the MPS method. The validity of this analysis method is verified by comparison with an experiment.

Analysis of the Disintegration of Charged Droplets Employing Boundary Element Method and Particle Method

It is well known that an initially charged droplet disintegrates repeatedly into several tiny sibling droplets and one parent droplet if the charge exceeds a certain value defined by the Rayleigh Limit. Many researchers have experimentally verified this phenomenon in their works. However, it is difficult to estimate the number, charge and mass of the sibling droplets because the sizes of the droplets are generally very small. In this paper, a new coupled analysis method for the disintegration of dielectric charged droplets employing boundary element method (BEM) and particle method is proposed. The behavior of the droplet during disintegration is analyzed by means of this method.

Numerical Analysis of Electromagnetic Levitation Employing Meshless Method Based on Weighted Least Square Method

Abstract Electromagnetic levitation is a kind of magnetohydrodynamic phenomena which is useful to measure the thermo-physical properties of pure metals under high temperature. However, this phenomenon is complicated and detailed mechanisms of this phenomenon have not been clarified yet. This study proposes the meshless method based on weighted least square method for the analysis of electromagnetic levitation. In this study, the fluid motion equation and the magnetic field equation are coupled by this method. The behavior of a molten metal under high-frequency magnetic field is calculated by this method.

Meshless Method Based on Weighted Least Square Method for Electrohydrodynamic Problems

This paper proposes a meshless method based on the weighted least square method for electrohydrodynamic problems. In this paper, the behavior of a water droplet in a uniform electric field is calculated by this method. The effectiveness of this analysis method is verified through comparison between the analyzed result and theoretical result of the electric potential around the droplet.

Coupled 3-D Analysis Employing FEM and Particle Method—Experimental Verification of Cold Crucible Induction Melting

This paper proposes a coupled 3-D finite element method (FEM) and particle method for the analysis of cold crucible induction melting. In this method, the magnetic field is calculated by FEM and the fluid motion equation and the heat equation of a molten metal are calculated by the particle method. The effectiveness of this method is verified through the analysis of the molten metal behavior in the crucible.

Numerical Simulation Model for FSW Employing Particle Method – Effect of Tool Angle on Fluid Motion

The friction stir welding (FSW) is known as non-melting joining. It used widely in the field of industry. Numerical analysis models for FSW also have been developed. In these models, the most frequently used method is a grid method (finite element method or finite difference method). However it is difficult or troublesome to calculate the advective term both for momentum and temperature employing these methods. It is also difficult to calculate the big deformation of the materials free surface. Moreover, complex process is required to analyze the dissimilar joining with respect to dealing with substance transfer. In this paper, to avoid these difficulties, particle method is adopted for FSW simulation. In particle method, advective term, substance transfer, and surface deformation are calculated automatically mainly because that Lagrangian approach is used. To verify the effectiveness of this method, fluid motion around the tool is examined by particle trace. As a result, relations between the rotating speed of the tool and area of plastic flow is evaluated.

Numerical Analysis of Ion Behavior Considering Charging Effect of a Dielectric Body

This paper proposes a coupled analysis method to deal with ion generation and ion drift in the air. Electric discharge is utilized in various products, and it is very important to clarify not only how much ion is generated but also where ion drifts in the air. The proposed method, which modeled interactions between electric field and ion behavior, including ion generation, ion drift, and charging of a dielectric body, has succeeded in calculating charge removal of a metallic target, which was tens of millimeters away from a pin electrode as a source of generated ion. The calculated results show that the amount of generated ion is drastically changed because electric field is affected by electric charge of ion in the air and charging of a dielectric body. This paper also reports a comparison of measured and calculated results of charge removal time of a metallic target, which were found to be in good agreement.