• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.34D no.3
• /
• pp.74-86
• /
• 1997

With continued miniaturization and development of new devices, the highly nonuniform oxidation of three-dimensional non-planar silicon structures plays an increasingly important role. In this paper, the three-dimensional finite element numerical simulator. Grwoth of oxide is a coupled process of diffusion of oxidant and deformation of oxide. Because boundaries of oxide are moved in each time step and LOCOS structure is formed three-dimensional shape of sruface, it is necessary to develope an efficient node control algorithm that can locally generate and eliminate the node. Therefore we have developed the optimized three-dimensional mesh generator which is cpable of refining and eliminating the meshes at the moving boundary of oxide, and hve developed three-dimensional finite element oxidation solver.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.12
• /
• pp.2103-2108
• /
• 2007

This study investigates the dynamic characteristics of Synchronous Reluctance Motor (SynRM), with segmental rotor structure, using finite element method in which the moving mesh technique is considered. The focus of this paper is the efficiency of on-line parameter identification system for position sensorless control of a SynRM considering saturation and iron loss. Comparisons are given with angle of the observer and those of proposed FEM & Preisach model of synchronous reluctance motor, respectively. The position sensorless control using identified motor parameters is realized, and the efficiency of the on-line parameter identification system is verified by experimental results.

• 한국전산유체공학회:학술대회논문집
• /
• 2011.05a
• /
• pp.187-193
• /
• 2011

In this report, We compared the actual test with the result of pow calculation and Resistance/Self-propulsion of the ship using STAR-CCM+ which is the commercial Reynolds Averaged Navier-Strokes(RANs) Solver. The calculation model was the KRISO Container Ship and 205K Bulk Carrier of Sungdong shipbuilding company. For this calculation, We used Realizable K-Epsilon model for flaw analysis, VOF method for the free surface creation, Moving Reference Frame method for reducing the POW calculation time, and Sliding Mesh method for Self-Propulsion analysis. Calculation of Resistance and Self-Propulsion includes the free-surface. And all calculations in this report were based on unstructured grids.

• 한국전산유체공학회:학술대회논문집
• /
• 2008.03b
• /
• pp.510-513
• /
• 2008

The traditional computational fluid or structure dynamics analysis approaches have contributed to solve many delicate engineering problems. But for the most of recent engineering problems which are influenced by fluid-structure interaction effect strongly, traditional individual approaches have limited analysis abilities for the exact simulation. Owing to above-mentioned reason, nowadays fluid-structure interaction analysis has become a matter of concern and interest. FSI analysis require several unprecedented techniques for the combining individual analysis tool into integrated analysis tool. The Arbitrary Lagrangian-Eulerian(ALE, in short) method is the new description of continum motion,which combines the advantages of the classical kinematical descriptions, i.e. Lagrangian and Eulerian description, while minimizing their respective drawbacks. In this paper, the ALE description is adapted to simulate fluid-structure interaction problems. An automatic re-mesh algorithm and a fluid-structure coupling process are included to analyze the interaction and moving motion during the 2-D axisymmetric solid rocket interior FSI phenomena simulation.

• 한국전산유체공학회:학술대회논문집
• /
• 2008.03b
• /
• pp.272-275
• /
• 2008

One of the important operating factors for the air-fuel pre-mixed conditions in an HCCI engine is an in-cylinder flow. In this study, unsteady in-cylinder air flow characteristics in a diesel engine as a reference engine of an HCCI engine development were numerically analysed. Unsteady flow analyses were conducted with the combination of 3 intake port inlets, then the in-cylinder air flow distribution and swirl ratio results from a case were compared with the results from the other cases.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.12 no.5
• /
• pp.25-31
• /
• 2004

In order to prepare for the large power diesel vehicle, the current trend of advanced nations is to shift from the aluminum alloy piston to the steel piston. In this research, a steel forging piston which replaces the aluminum alloy piston is developed to improve the power performance of the diesel engine. The three dimensional flow and combustion analysis of the target engine is conducted. Using the result of the analysis, the piston is optimized, and a prototype of the articulated steel forging piston is built. The reliability of the piston has been evaluated through durability test using a Hydropuls Test Machine for 300,000 km.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1996.11a
• /
• pp.67-70
• /
• 1996

In this paper, the three-dimensional stress effect of thermal oxide is simulated. We developed the three-dimensional finite element numerical simulator including three-dimensional adaptive mesh generator that is able to refine and eliminate nearby moving boundary of oxide, and oxidation solver with stress model. The main effect of deformation at the coner area of oxide is due to distribution of oxidant, but the deformation of oxide is affected by the stress in the oxide. In the island structure which is the structure mostly covered with nitride and a coner is opened to oxidation, oxidation is reduced at the coner by compressive stress. In the hole structure which is the structure mostly opened to oxide and a coner is covered with nitride, however, oxidation is increased at the coner by tensile stress.

• Proceedings of the KIEE Conference
• /
• 2006.07b
• /
• pp.673-674
• /
• 2006

This study investigates the dynamic characteristics of Synchronous Reluctance Motor (SynRM), with segmental rotor structure, using finite element method in which the moving mesh technique is considered. The focus of this paper is the sensorless vector control parameters estimation of SynRM under saturation and iron loss. Comparisons are given with dynamic characteristics of normal single B-H nonlinear solutions and those of proposed FEM & Preisach model of synchronous reluctance motor, respectively.

• Proceedings of the KIEE Conference
• /
• 1994.07a
• /
• pp.153-155
• /
• 1994

Electric machines such as motors which have moving parts are desgined for producing mechanical force or torque. The accurate calculation of electromagnetic force and torque is important in the design these machines, Electromagnetic force calculation method using the results of Finite Element Method(FEM) has been presented variously in 2-D problems. Typically the Maxwell's Stress Tensor method and the method of virtual work are used. In the problems including current source, magnetic vector potentials(MVP) have mostly been used as an unknown variables for field analysis by numerical method; e, g. FEM. This paper, thus, introduces both methods using MVP in 3-D case. To verify the usefulness of presented methods, a solenoid model is chosen and analyzed by 3-D and axisymmetrical FEM. In each case, the calculated force are tabulated for several mesh schemes.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.7 no.5
• /
• pp.920-938
• /
• 2015

In the present study, a numerical prediction method on the hydrodynamic interaction force and moment between two ships in shallow and restricted waterway is presented. Especially, the present study proposes a methodology to overcome the limitation of the two dimensional perturbation method which is related to the moored-passing ship interaction. The validation study was performed and compared with the experiment, firstly. Afterward, in order to propose a methodology in terms with the moored-passing ship interaction, further studies were performed for the moored-passing ship case with a Reynolds Averaged Navier-Stokes (RANS) calculation which is using OpenFOAM with Arbitrary Coupled Mesh Interface (ACMI) technique and compared with the experiment result. Finally, the present study proposes a guide to apply the two dimensional perturbation method to the moored-passing ship interaction. In addition, it presents a possibility that the RANS calculation with ACMI can applied to the ship-ship interaction without using a overset moving grid technique.