• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2003년도 추계학술발표대회 요약집
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• pp.114-114
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• 2003

• 한국태양에너지학회 논문집
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• 제26권3호
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• pp.99-110
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• 2006

This study focused on the emission rate of the construction materials. The method of study is as follows. First, validation of small chamber method to determine emission rate of construction material was performed by CFD simulation. For the result of this study, uniform air velocity in small chamber was founded, and small chamber as a test material for emission rate was validated. Second, the construction materials were categorized by their feature and the emission rate of volatile organic compound was determined. Totally, VOCs emission rate of 49 materials were determined.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2010년 춘계학술대회논문집
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• pp.103-108
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• 2010

This article presents computational fluid dynamics (CFD) simulations of nanoparticle movements and flow characteristics in laboratory-scale electrostatic precipitator (ESP) without corona discharge, and for simulation, it uses the commercial CFD program(CFD-ACE) including electrostatic theory and Lagrangian-based equation for nanoparticle movement. For validation of CFD results, a simple cylindrical type of ESP is simulated and numerical prediction shows fairly good agreement with the analytical solution. In particular, the present study investigates the effect of particle diameter, inlet flow rate, and applied electric potential on particle collection efficiency and compares the numerical prediction with the experimental data, showing good agreement. It is found that the particle collection efficiency decreases with increasing inlet flow rate because the particle detention time becomes shorter, whereas it decreases with the increase in nanoparticle diameter and with the decrease of applied electric voltage resulting from smaller terminal electrostatic velocity.

• Wind and Structures
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• 제20권4호
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• pp.565-578
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• 2015

A wind energy assessment is an integrated analysis of the potential of wind energy resources of a particular area. In this work, the wind energy potentials for Mauritius have been assessed using a Computational Fluid Dynamics (CFD) model. The approach employed in this work aims to enhance the assessment of wind energy potentials for the siting of large-scale wind farms in the island. Validation of the model is done by comparing simulated wind speed data to experimental ones measured at specific locations over the island. The local wind velocity resulting from the CFD simulations are used to compute the weighted-sum power density including annual directional inflow variations determined by wind roses. The model is used to generate contour maps of velocity and power, for Mauritius at a resolution of 500 m.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2005년도 연구개발 발표회 논문집
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• pp.233-239
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• 2005

In the present study, numerical simulation has been performed to investigate the characteristics of the mist flow through the fire suppression nozzles. The commercial CFD software, FLUENT with the proper modeling was applied in both the internal and external flow region of the spray nozzles. Applications were done to the full cone nozzle for the operation range of the low pressure and high flow-rate. Numerical validation was proved by the comparison of the experimental data. Parametric study of the key design factors was tried to improve the performance.

• Wind and Structures
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• 제22권4호
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• pp.503-524
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• 2016

The suitability of Computational Fluid Dynamics (CFD) simulations on the built environment for the purpose of estimating average roughness characteristics and for studying wind flow patterns within the environment is assessed. Urban models of various levels of complexity are considered including an empty domain, array of obstacles arranged in regular and staggered manners, in-homogeneous roughness with multiple patches, a semi-idealized built environment, and finally a real built environment. For each of the test cases, we conducted CFD simulations using RANS turbulence closure and validated the results against appropriate methods: existing empirical formulas for the homogeneous roughness case, empirical wind speed models for the in-homogeneous roughness case, and wind tunnel tests for the semi-idealized built environment case. In general, results obtained from the CFD simulations show good agreement with the corresponding validation methods, thereby, giving further evidence to the suitability of CFD simulations for built environment studies consisting of wide-ranging roughness. This work also provides a comprehensive overview of roughness modeling in CFD-from the simplest approach of modeling roughness implicitly through wall functions to the most elaborate approach of modeling roughness explicitly for the sake of accurate wind flow simulations within the built environment.

• Nuclear Engineering and Technology
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• 제53권9호
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• pp.2775-2787
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• 2021

At present, most of the widely used system codes for nuclear safety analysis are one-dimensional, which cannot effectively simulate the flow field of the reactor core or other structures. This is true even for the system codes containing three-dimensional modules with limited three-dimensional simulation function such as RELAP-3D. In contrast, the computational fluid dynamics (CFD) codes excel at providing a detailed three-dimensional flow field of the reactor core or other components; however, the computational domain is relatively small and results in the very high computing resource consuming. Therefore, the development of coupling codes, which can make comprehensive use of the advantages of system and CFD codes, has become a research focus. In this paper, a review focus on the researches of coupled CFD and thermal-hydraulic system codes was carried out, which summarized the method of coupling, the data transfer processing between CFD and system codes, and the verification and validation (V&V) of coupled codes. Furthermore, a series of problems associated with the coupling procedure have been identified, which provide the general direction for the development and V&V efforts of coupled codes.

• 한국항공우주학회지
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• 제50권10호
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• pp.669-676
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• 2022

본 논문에서는 비정렬 CFD 해석자 UMSAPv에 적용된 중첩 격자 기법의 검증을 위하여 항공기에 장착된 store의 장착하중을 구하였다. 먼저, 잘 알려진 Eglin Wing/Pylon/Finned store 문제에 대해 UMSAPv의 중첩 격자 기법을 검증하였다. 다음으로 F/A-18C clean 형상에서 대하여 받음각에 따른 아음속 유동해석을 수행하였다. 계산 결과를 정렬 CFD 해석자인 MSAPv을 사용한 선행연구결과와 비교하여 Umsapv의 해석능력을 검증하였다. 마지막으로 F/A-18C/JDAM의 장착하중은 중첩 격자와 단일 격자로 수행하였다. 계산된 결과는 다른 CFD결과, 실험 및 비행시험과 비교하였다.

• 한국해안·해양공학회논문집
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• 제31권4호
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• pp.199-208
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• 2019

2차원 조파수조에서 완전반사 조건의 규칙파 조파 실험을 수행하고, 세 가지 서로 다른 CFD 모델의 성능을 검증하였다. 사용된 CFD 모델은 CADMAS-SURF, olaFlow 및 KIOSTFOAM이었다. 쇄파가 발생하지 않는 조건, 중복파의 쇄파가 발생하는 조건, 입사파의 쇄파가 발생하는 조건에서 실험 및 모델링을 수행하였다. 그 결과 세 모델 중 KIOSTFOAM이 실험결과를 가장 잘 재현하는 것으로 나타났다. CADMAS-SURF는 KIOSTFOAM에 비해 계산 시간은 줄어들지만 계산 정확도가 상대적으로 더 낮았다. olaFlow는 계산은 가장 빠르지만 조파 경계에서 반사파 흡수가 만족스럽지 않고 쇄파 발생 시 파랑에너지를 과도하게 소산시키는 것으로 나타났다.

• 한국농공학회논문집
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• 제60권3호
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• pp.27-36
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• 2018

Effective pesticide applications are needed to assure the quality and economic competitiveness of fruit production and lower the risk of spray drift. Experimental studies have shown that better spray coverage and less driftability require an understanding of the transport of spray droplets within turbulent airflows in the orchard and the interaction between droplet dynamics and tree canopies. This study developed a computational fluid dynamics (CFD) model to predict pesticide flows in the orchard and spray drift discharged from an air-assisted orchard sprayer. The model represented the transport of spray droplets as well as droplets captured by tree canopies, which were modeled as a conical porous model and branched tree model. Validation of the CFD model was accomplished by comparing the CFD results with field measurements. Spray depositions inside tree canopies and at off-target locations were in good agreement with the measurements. The resulting data presented that 38.6%~42.3% of the sprayed droplets were delivered to the tree canopies while 13.6%~20.1% were drifted out of the orchard, part of them reached farther than 200 m from the orchard. The study demonstrates that CFD model can be used to evaluate spray application performance and spray drift potential.