• Title/Summary/Keyword: CFD 유동해석

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Numerical Analysis on the Thermal and Fluid in Air Conditioning Duct for Marine Offshore (해양 구조물용 공조덕트 열유동에 관한 수치해석)

  • Yi, Chung-Seob;Lee, Byung-Ho;Chin, Do-Hun
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.17 no.5
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    • pp.23-29
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    • 2018
  • This study is about the distribution of heat transfer in air conditioning ducts used for marine vessels and oil drilling platforms. As the convective heat transfer coefficient increased, heat transfer was conducted dynamically to inside as it exited to the outlet of duct. The experiment was to determine if the amount of heat transfer generated at the duct exit increased as the convective heat transfer coefficient increased. When the convective heat transfer coefficient was low, the temperature of the duct showed a relatively high temperature difference between the outside and inside of the duct due to the temperature influence of the internal fluid. In case of temperature distribution generated the volume of the duct along the change of the convective heat transfer coefficient, the temperature descended as heat transfer was promoted and the convective heat transfer coefficient increased.

Analysis of Coating Flow Characteristics in Wet-on-Wet Optical Fiber Liquid Coating Process (광섬유 WOW 액상코팅 공정의 코팅액 유동특성 해석연구)

  • Kim, Kyoungjin;Park, Joong-Youn
    • Journal of the Semiconductor & Display Technology
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    • v.16 no.4
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    • pp.91-96
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    • 2017
  • In this computational study of optical fiber manufacturing, WOW (wet-on-wet) double coating process on freshly drawn glass fiber has been numerical modelled and simulated using a simplified geometry of typical optical fiber coating apparatus. The numerical domain includes primary and secondary coating dies along with secondary coating cup and the interface between primary and secondary coating liquids are investigated using level set method. Coating liquid viscosity is an important parameter and its dependence on temperature is also considered. Since there would be possibility for pressure and temperature of primary coating liquid to be increased substantially at high fiber drawing speed, the effects of increased pressure and temperature of primary coating liquid are examined on flow patterns of coating liquids in secondary coating cup. In case that both pressure and temperature of primary coating liquid are high enough, liquid interface becomes noticeably unstable and this flow instability could adversely affect the uniform coatings and final quality of produced optical fiber.

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Analytical Study on Unsteady Flow Characteristics of Urea-SCR Single Hole Injector depend on Nozzle Shape Change (Urea-SCR 단홀 Injector 노즐형상 변화에 따른 비정상유동특성의 해석적 연구)

  • Hwang, Jun Hwan;Park, Sung-Young
    • Journal of ILASS-Korea
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    • v.24 no.3
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    • pp.105-113
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    • 2019
  • In this paper, a study of Urea-SCR System for Dosing Injector for responding to enhanced environmental regulations has been conducted. There is a limit to the experimental approach due to the structural characteristics of the injector. In order to overcome this problem, The analysis was performed assuming unsteady turbulent flow through computational fluid analysis and the internal flow characteristics of the injector were analyzed. By changing the nozzle shape of the injector, the performance factors of the swirl injector by shape were selected and compared. The design parameters were modified by changing the diameter of the nozzle at a constant ratio compared to the base model. Swirl coefficient, outlet mass flow, and sac volume were selected as performance parameters of the injector. The Conv. model to which the taper was applied showed the dominance in mass flow rate, discharge coefficient and swirl because of the smooth fluid flow by shape. Swirl coefficient, outlet mass flow, and sac volume were selected as performance parameters of the injector. As a result of the comparison coefficient derivation with those performance parameters for comparing the performance of the model-specific injector, the Conv-140 model with the nozzle diameter expanded by 140% showed the best value of the comparison coefficient.

Numerical Analysis on the Thermal and Fluid in Air Conditioning Duct for Marine Offshore (해양 구조물용 공조덕트 열유동에 관한 수치해석)

  • Yi, Chung-Seob;Lee, Byung-Ho;Chin, Do-Hun
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.18 no.2
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    • pp.7-13
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    • 2019
  • This study is about distributions of heat transfer in air conditioning duct used for marine and oil drilling ship. As the convective heat transfer coefficient increased, heat transfer was conducted dynamically to inside as it exited to the outlet of duct. So, it was checked that the amount of heat transfer generated at duct increased as the convective heat transfer coefficient increased. In case the convective heat transfer coefficient was low, the temperature of duct showed the relatively high temperature distribution due to the temperature influence of internal fluid as the heat transfer between the outside and inside of the duct. In case of temperature distribution generated the volume of the duct along the change of the convective heat transfer coefficient, it was found out that the temperature descended as heat transfer was promoted and the convective heat transfer coefficient increased.

A Study on the Flow and Structural Analysis in an Air Conditioning Duct for Marine Offshore (해양 구조물용 공조덕트 유동 및 구조해석에 관한 연구)

  • Yi, Chung-Seob;Lee, Byung-Ho;Chin, Do-Hun
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.18 no.3
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    • pp.88-93
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    • 2019
  • This study concerns the distributions of flow in an air conditioning duct used for a marine and oil drilling ship. From the results of carrying out flow analysis and structural analysis of a ventilation duct applied to a marine structure, the following conclusion could be gained. The pressure tended to increase as the flow velocity at the inlet increased and the pressure at the inlet increased. It was recognized that the pressure decreased due to the influence of a corrugated tube when it entered and exited from the duct. As a result of structural analysis, a higher train was generated at the corrugated tube compared with the duct. In addition, in the case of the internal pressure of 0.7MPa, which was the designed load, it was found that there was almost no influence as it was within 0.1mm.

A Study on the Optimal Design According to the Piston Shape of the 3/8 Hydraulic Quick Coupler (3/8" 유압 퀵 커플러의 피스톤형상을 고려한 최적설계에 관한 연구)

  • Kim, Nam-Yong;Wu, Yu-Ting;Qin, Zhen;Cho, Yong-Min;Lyu, Sung-Ki
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.20 no.2
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    • pp.66-71
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    • 2021
  • A hydraulic quick coupler is a component used to easily connect or disconnect pipes or hoses that transfer high pressure fluid without leakage in various mechanical devices. In this study, to obtain an optimal design of a 3/8" hydraulic quick coupler, the effect of different shapes of the internal piston on the internal flow characteristics of the coupler was analyzed and evaluated through numerical analysis based on computational fluid dynamics. Subsequently, the optimal shape design of the internal piston was obtained by comparing the flow characteristics results such as velocity distribution, temperature distribution, and the pressure drop of the hydraulic quick coupler.

Numerical study on pressure drop with moving contact lines of dry slug flow in a hydrophobic minichannel (소수성 미니채널 내 움직이는 접촉선을 가진 액체슬러그의 압력 강하에 대한 수치해석)

  • Jeon, Jun Ho;Park, Su Chung;Yu, Dong In;Kim, Tae Hun;Lee, Yeon Won
    • Journal of the Korean Society of Visualization
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    • v.18 no.3
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    • pp.116-121
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    • 2020
  • In this study, a single-phase analysis of droplet slug with different contact angles was performed based on the visualization of experimental results. Droplet slug - flowing between gases in a hydrophobic mini channel - moves with a triple contact line without a gas liquid film on the wall. The results show that the rotational flow inside the droplet occurred; this was compared and verified with the results of two-phase analysis. The pressure field shows pressure rise at the front and rear ends. The effective length - the section that satisfies the laminar flow condition - became shorter as the droplet velocity increased. The Choi's correlation for the effective length agrees with this analysis results with a slight difference. This difference is judged as the difference in the contact angle of the slug model.

Study on the Optimal Design of the Nozzle Shape of the 700 bar Hydrogen Refueling Nozzle for Hydrogen Electric Vehicles (수소전기차용 700 bar 수소충전노즐의 노즐형상을 고려한 최적설계에 관한 연구)

  • Baek, Jin-Uk;Gwak, Gi-Myung;Kim, Nam-Yong;Cho, Yong-Min;Lyu, Sung-Ki
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.21 no.7
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    • pp.28-33
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    • 2022
  • In this study, we analyze the flow characteristics according to the internal shape of a 700bar hydrogen charging gun for hydrogen electric vehicles. When charging hydrogen, it receives a high-pressure charging pressure. At this time, we analyze the flow characteristics according to the shape of the nozzle and find the shape of the nozzle that minimizes energy loss. Ultimately, the optimal design of the nozzle was obtained by comparing the pressure difference between the inlet pressure and outlet pressure under a fixed mass flow condition.

Analysis of Flow Characteristics of Multiple Filter System (다중 필터 시스템의 유동특성 해석)

  • In-Soo Son;Mi-Young Seo;Jun-Ho Kim;Jin-Soek Yu
    • Journal of the Korean Society of Industry Convergence
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    • v.26 no.4_2
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    • pp.615-621
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    • 2023
  • In this study, flow analysis of single, double, and triple filter systems of cylindrical structures was performed to analyze the flow characteristics of each filter. As a result of the flow analysis of the filter system, the number of filters and the pressure drop rate tend to be proportional to each other. It was found that the area passing through the inside of the filter had almost the same pressure. The maximum pressure drop rate of the triple filter system was about 14.9% for the forward-flow and about 12.4% for the reverse-flow. It was determined that the performance of the filter was stable within 20% of the allowable pressure drop rate of the filter system, which is the standard presented to the Korea Water Technology Certification Institute(KWTCI). In the future, a study on the decompression characteristics of the filter system according to the effect of the arrangement interval and filter density of the triple filter will be conducted.

Numerical Analysis in a 1 kWe SOFC Stack for the Flow Phenomena (1 kWe 급 고체산화물 연료전지 스택에서의 유동 해석)

  • KUNWOO YI;YOUNG JIN KIM;HAOYUAN YIN;HYEON JIN KIM;KYONG SIK YUN;JI HAENG YU
    • Journal of Hydrogen and New Energy
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    • v.34 no.2
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    • pp.196-204
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    • 2023
  • This study performed the numerical analysis of the internal flow phenomena of 1 kWe-class solid oxide fuel cell (SOFC) stacks with internal manifold type and planar cells using commercial computational fluid dynamics (CFD) software, Star-CCM+. In particular, the locations where the turbulent phenomena occur inside the SOFC stack were investigated. In addition, the laminar flow model and the standard k-ε turbulent model were used to calculate the SOFC stack, separately. And, the calculation results of both laminar and turbulent models were compared. The calculation results showed that turbulent phenomena occurred mainly in the cathode flow. Especially, the turbulent phenomena were found in the cathode inlet/outlet region, and local turbulence occurred in the end plate near the inlet pipe.