• Title/Summary/Keyword: 3D numerical simulation

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Numerical Simulation of Tribological Phenomena Using Stochastic Models

  • Shimizu, T.;Uchidate, M;Iwabuchi, A.
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2002.10b
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    • pp.235-236
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    • 2002
  • Tribological phenomena such as wear or transfer are influenced by various factors and have complicated behavior. Therefore, it is difficult to predict the behavior of the gribological phenomena because of their complexity. But, those tribological phenomena can be considered simply as to transfer micro material particles from the sliding interface. Then, we proposed the numerical simulation method for tribological phenomena such as wear of transfer using stochastic process models. This numerical simulation shows the change of the 3-D surface topography. In this numerical simulation, initial 3-D surface toughness data are generated by the method of non-causal 2-D AR (autoregressive) model. Processes of wear and transfer for some generated initial 3-D surface data are simulated. Simulation results show successfully the change of the 3-D surface topography.

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Modeling of Numerical Simulation in Powder Injection Molding Filling Process (분말사출성형 충전공정에 대한 수치모사 모델)

  • 권태현;강태곤
    • Journal of Powder Materials
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    • v.9 no.4
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    • pp.245-250
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    • 2002
  • In this paper we presented numerical method for the simulation of powder injection molding filling process, which is one of the key processes in powder injection molding. Rheological properties of powder binder mixture such as slip phenomena and yield stress were introduced into the numerical analysis model of powder injection molding filling simulation. Numerical model can be classified into two types. One is 2.5D model which can be introduced to a arbitrary thin geometry and the other is full 3D model which can be applied to a general 3D shape. For 2.5D model we showed the validity of our CAE system with several verification examples. Finally we suggested flow analysis model for 3D powder injection molding filling simulation.

3D numerical simulation of temperature on Pilot tube

  • Ying Wang;Baogeng Ding
    • 한국전산유체공학회:학술대회논문집
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    • 2006.05a
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    • pp.248-251
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    • 2006
  • Multi-physics problem is considered for the Pitot tube located in uniform freon gas flow with high Mach number and the 3D numerical results of temperature on Pitot tube is given. The model is created by using structural module of ANSYS, the grids are obtained by ICEM, and the problem is solved and the data post-processing is done by CFX.

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3D Modeling of a Fabric based on its 3D Microstructure Image and Application of the Model of the Numerical Simulation of Heat Transfer

  • Lee, Hyojeong;Lee, Heeran;Eom, Ran-i;Lee, Yejin
    • Journal of Fashion Business
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    • v.20 no.3
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    • pp.30-42
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    • 2016
  • The objective of this study was to perform 3D solid modeling from 3D scanned surface images of cotton and silk in order to calculate the thermal heat transfer responses using numerical simulations. Continuing from the previous methodology, which provided 3D surface data for a fabric through optical measurements of the fabric microstructure, a simplified 3D solid model, containing a defined unit cell, pattern unit and fabric structure, was prepared. The loft method was used for 3D solid-model generation, and heat transfer calculations, made for the fabric, were then carried out using the 3D solid model. As a result, comprehensive protocols for 3D solid-model generation were established based on the optical measurements of real fabric samples. This method provides an effective means of using 3D information for building 3D models of actual fabrics and applying the model in numerical simulations. The developed process can be used as the basis for other analogous research areas to investigate the physical characteristics of any fabrics.

A FEASIBILITY STUDY ON THE NUMERICAL PRE-ASSEMBLY SIMULATION USING 3D LASER SCANNING MEASUREMENT

  • Kyoungmin Kim ;Seok Kim ;Chan-Hyuk Park ;Kyong Ju Kim
    • International conference on construction engineering and project management
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    • 2005.10a
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    • pp.1193-1198
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    • 2005
  • The pre-assembly takes a large portion of the fabrication cost of steel bridges. In order to save the fabrication cost through the improvement of the conventional pre-assembling process, this research investigates a numerical pre-assembly simulation as an alternative to current pre-assembling process. The 3D laser scanning was utilized in site and measuring data for steel box were analyzed. The productivity of pre-assembly simulation system is compared with the conventional pre-assembling system. This paper identifies feasibility on the alternative pre-assembling process and then proposes the scheme of the pre-assembly simulation system development satisfying the current pre-assembly inspection of standards.

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Application of 3-D Numerical Method (LES-WASS-3D) to Estimation of Nearshore Current at Songdo Beach with Submerged Breakwaters (잠제가 설치 된 부산 송도해수욕장의 해빈류 예측에 관한 3차원 수치해석기법(LES-WASS-3D)의 적용)

  • Hur, Dong-Soo;Lee, Woo-Dong;Kim, Myoung-Kyu;Yoon, Jong-Sung
    • Journal of Ocean Engineering and Technology
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    • v.27 no.4
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    • pp.14-21
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    • 2013
  • This study examined the field application of a 3-D numerical model (LES-WASS-3D) to the estimation of the nearshore current at Songdo beach, Busan. The wave and tide conditions observed at Songdo beach during Typhoon Ewiniar (July 10, 2006) were used in a numerical simulation. The numerical wave heights were in good agreement with the field data. The spatial distributions of the wave heights, mean water levels, and mean flows obtained from the numerical simulation are discussed in relation to the bottom topographical change near Songdo beach before and after Typhoon Ewiniar. The results revealed that LES-WASS-3D is a powerful tool for estimating the nearshore current in the field.

Numerical Wave Tank Technology for Multipurpose Simulation in Marine Environmental Engineering (해양환경공학의 다목적 시뮬레이션을 위한 수치파랑수조 기술)

  • 박종천
    • Journal of Ocean Engineering and Technology
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    • v.17 no.4
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    • pp.1-7
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    • 2003
  • A virtual reality technology for multipurpose numerical simulation is developed to reproduce and investigate a variety of ocean environmental problems in a 3D Numerical Wave Tank(NWT). The governing equations for solving incompressible fluid motion are Navier-Stokes equation and continuity equation. The Marker-Density function technique is adopted to implement the fully nonlinear freesurface kinematic condition. The marine environmental situations, i.e., waves, currents, etc., are reproduced by use of multi-segmented wavemakers on the basis of the so-called ″snake-principle″. In this paper, some numerical reproduction techniques for regular, and irregular waves, multi-directional waves, Bull's-eye wave. wave-current, and solitary wave are presented, and a model test in motion with large amplitude of roll angle is conducted in the developed 3D-NWT, using a overlaid grid system.

A numerical study on rock cutting by a TBM disc cutter using SPH code (SPH 코드를 사용한 TBM 디스크커터의 암석 절삭에 대한 수치해석적 연구)

  • Jeong, Ho-Young;Jeon, Seok-Won;Cho, Jung-Woo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.15 no.3
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    • pp.345-356
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    • 2013
  • Numerical simulation on rock cutting by a TBM disc cutter was carried out using SPH (Smoothed Particle Hydrodynamics) code. AUTODYN3D, a commercial software program based on finite element method, was used in this study. The three-dimensional geometry of a disc cutter and a rock specimen were modeled by Lagrange and SPH code respectively. The numerical simulation was carried out for Hwangdeung granite for 10 different cutting conditions. The results of the numerical simulation, i.e. the relation between cutter force and failure behavior, had a good agreement with those from LCM test. The cutter forces measured in the numerical simulation had 10% deviation from the LCM test results. Moreover, the optimum cutter spacing was almost identical with the experimental results. These results indicate that SPH code can be successfully used had applicability for simulation on rock cutting by a TBM disc cutter. However, further study on Lagrange-SPH coupled modelling would be necessary to reduce the computation time.

Numerical Investigation on Flow Pattern over Backward-Facing Step for Various Step Angles and Reynolds numbers

  • Lee, Jeong Hu;Nguyen, Van Thinh
    • Proceedings of the Korea Water Resources Association Conference
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    • 2021.06a
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    • pp.60-60
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    • 2021
  • Investigating Backward-Facing Step(BFS) flow is important in that it is a representative case for separation flows in various engineering flow systems. There have been a wide range of experimental, theoretical, and numerical studies to investigate the flow characteristics over BFS, such as flow separation, reattachment length and recirculation zone. However, most of such previous studies were concentrated only on the perpendicular step angle. In this study, several numerical investigations on the flow pattern over BFS with various step angles (10° ~ 90°) and expansion ratios (1.48, 2 and 3.27) under different Reynolds numbers (5000 ~ 64000) were carried out, mainly focused on the reattachment length. The numerical simulations were performed using an open source 3D CFD software, OpenFOAM, in which the velocity profiles and turbulence intensities are calculated by RANS (Reynolds Averaged Navier-Stokes equation) and 3D LES (Large Eddy Simulation) turbulence models. Overall, it shows a good agreement between simulations and the experimental data by Ruck and Makiola (1993). In comparison with the results obtained from RANS and 3D LES, it was shown that 3D LES model can capture much better and more details on the velocity profiles, turbulence intensities, and reattachment length behind the step for relatively low Reynolds number(Re < 11000) cases. However, the simulation results by both of RANS and 3D LES showed very good agreement with the experimental data for the high Reynolds number cases(Re > 11000). For Re > 11000, the reattachment length is no longer dependent on the Reynolds number, and it tends to be nearly constant for the step angles larger than 30°.) Based on the calibrated and validated numerical simulations, several additional numerical simulations were also conducted with higher Reynolds number and another expansion ratio which were not considered in the experiments by Ruck and Makiola (1993).

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Motion Simulation of FPSO in Waves through Numerical Sensitivity Analysis (수치 민감도 해석을 통한 파랑중 FPSO운동 시뮬레이션)

  • Kim, Je-in;Park, Il-Ryong;Suh, Sung-Bu;Kang, Yong-Duck;Hong, Sa-Young;Nam, Bo-Woo
    • Journal of Ocean Engineering and Technology
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    • v.32 no.3
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    • pp.166-176
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    • 2018
  • This paper presents a numerical sensitivity analysis for the simulation of the motion performance of an offshore structure in waves using computational fluid dynamics (CFD). Starting with 2D wave simulations with varying numerical parameters such as grid spacing and CFL value, proper numerical conditions were found for accurate wave propagation that avoids numerical diffusion problems. These results were mapped on 2D error distributions of wave amplitude and wave length against the numbers of grids per wave length and per wave height under a given CFL condition. Finally, the 2D numerical sensitivity result was validated through CFD simulation of the motion of a FPSO in waves showing good accuracy in motion RAOs compared with existing potential flow solutions.