• 제목/요약/키워드: Fluid Visualization

검색결과 467건 처리시간 0.023초

사이드 채널형 재생블로워의 내부 유동 가시화 (Visualization of Flow inside the Side Channel Type Regenerative Blower)

  • 양현모;이경용;최영석;정경석
    • 한국유체기계학회 논문집
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    • 제16권5호
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    • pp.24-28
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    • 2013
  • Visualization of internal flow of a regenerative blower has been made by injecting a tracer directly into the flow. For the convenience of visualization, working fluid has been replaced by water and marbling color oil has been used as a tracer. Oil droplet has been injected near the inlet of the blower and the streak has been recorded using a high speed camera with the illumination of high power light sources. At first, droplets have irregular motion in the near inlet area and enter into a groove of the impeller. Then the droplets circulate inside the groove while translated by the rotational motion of the impeller. When the droplets get out of the impeller groove, their speed is lower than that of impeller. And the droplets repeatedly enter into the groove and circulate inside the grooves. Then the droplets either flow to the outlet or reenter into the inlet area through stripper. Through this experimental study, internally circulating motion of the flow inside a regenerative blower has been characterized.

100kW용 풍력발전기의 블레이드에 대한 유동/구조 연성해석 (Analysis of Fluid Structure Interaction on 100kW-HAWT-blade)

  • 김윤기;김경천
    • 한국가시화정보학회지
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    • 제4권1호
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    • pp.41-46
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    • 2006
  • In this study, one-way fluid structure interaction analysis(FSI) on wind turbine blade was performed. Both a quantitative fluid analysis on 3-bladed wind turbine and a structural analysis using the surface pressure data resulting from fluid analysis were carried out. Streamlines and angle of attack was easily acquired from analysis results, we showed the inlet velocity that the stall begins to occur. In the structural analysis, structural displacement and maximum stress of the two comparative models was calculated. The location that has maximum stress was found. The pressure difference between back and front part of the blade increases as the inlet velocity increase. The torque and maximum with regard to inlet velocity was also presented.

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그라비아 옵셋 프린팅 공정에서의 잉크전이 메커니즘 해석 연구 (Analysis of Ink Transfer Mechanism in Gravure-offset Printing Process)

  • 이승현;남기상;이택민;윤덕균;조정대
    • 한국정밀공학회지
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    • 제28권10호
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    • pp.1146-1152
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    • 2011
  • Ink transfer process is very important to determine quality of printed pattern, therefore its mechanism should be understood to control printing quality. Although there have been many attempts to understand ink transfer mechanism by numerical simulation and experimental studies, their model was too much simple to model realistic printing process and our understanding is not enough yet. In this paper we designed ink transfer visualization system to present flow visualization of ink transfer process for gravure offset printing. We considered rotational effect of blanket roll which is related with printing speed and used non-Newtonian fluid as working fluid such as Ag paste. For printing unit, cantilever-type blanket roll is used for convenient visualization of ink transfer. Serial images were captured continuously by using high-speed CMOS camera and long range microscope. We investigated the effects of various design parameters such as printing speed and pattern angle on the ink transfer process. We found more stretched ink filament for non-Newtonian fluid than Newtonian fluid. As increasing printing speed, length of stretched ink filament and height of break-up point are also increased. We also compared ink transfer process between CD and MD pattern and its relationship with ink transfer mechanism.

전산유체역학을 이용한 실시간 유체 애니메이션 기술 (Real-time Flow Animation Techniques Using Computational Fluid Dynamics)

  • 강문구
    • 한국가시화정보학회지
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    • 제2권2호
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    • pp.8-15
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    • 2004
  • With all the recent progresses in computer hardware and software technology, the animation of fluids in real-time is still among the most challenging issues of computer graphics. The fluid animation is carried out in two steps - the physical simulation of fluids immediately followed by the visual rendering. The physical simulation is usually accomplished by numerical methods utilizing the particle dynamics equations as well as the fluid mechanics based on the Navier-Stokes equations. Particle dynamics method is usually fast in calculation, but the resulting fluid motion is conditionally unrealistic. The methods using Navier-Stokes equation, on the contrary, yield lifelike fluid motion when properly conditioned, yet the complexity of calculation restrains this method from being used in real-time applications. This article presents a rapid fluid animation method by using the continuum-based fluid mechanics and the enhanced particle dynamics equations. For real-time rendering, pre-integrated volume rendering technique was employed. The proposed method can create realistic fluid effects that can interact with the viewer in action, to be used in computer games, performances, installation arts, virtual reality and many similar multimedia applications.

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SPH 기반의 유체 및 용해성 강체에 대한 시각-촉각 융합 상호작용 시뮬레이션 (Real-time Simulation Technique for Visual-Haptic Interaction between SPH-based Fluid Media and Soluble Solids)

  • 김석열;박진아
    • 한국가시화정보학회지
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    • 제15권1호
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    • pp.32-40
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    • 2017
  • Interaction between fluid and a rigid object is frequently observed in everyday life. However, it is difficult to simulate their interaction as the medium and the object have different representations. One of the challenging issues arises especially in handling deformation of the object visually as well as rendering haptic feedback. In this paper, we propose a real-time simulation technique for multimodal interaction between particle-based fluids and soluble solids. We have developed the dissolution behavior model of solids, which is discretized based on the idea of smoothed particle hydrodynamics, and the changes in physical properties accompanying dissolution is immediately reflected to the object. The user is allowed to intervene in the simulation environment anytime by manipulating the solid object, where both visual and haptic feedback are delivered to the user on the fly. For immersive visualization, we also adopt the screen space fluid rendering technique which can balance realism and performance.

Fluid Flow and Heat Transfer in a Super high-Pressure Mercury Lamp using CFD

  • Jang, Dong Sig;Lee, Yeon Won;Li, Kui Ming;Parthasarathy, Nanjundan;Choi, Yoon Hwan
    • International Journal of Safety
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    • 제11권2호
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    • pp.5-9
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    • 2012
  • The discharge properties of super high-pressure mercury lamp are due to resistance heating for energy input, and results in temperature increase. The cooling equilibrium state is reached by the heat conduction, convection and radiation. In order to predict the fluid flow and heat transfer in and around the mercury lamp accurately, its visualization is of utmost importance. Such visualization is carried out by CFD program in this study. We focus on Anode shape to calculate four cases, namely AA, AB, AC and AD separately, and compare the temperature distribution and velocity vector in each case to predict cooling capacity and fluid flow properties. It can be concluded that the shape of anode plays an important role that affects the fluid flow and heat transfer in a mercury lamp.

배경회전이 있는 싱크 유동의 이론 및 수치해석 (Theoretical and Numerical Analysis of Sink Flows under a Background Rotation)

  • 서용권;여창호
    • 한국가시화정보학회지
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    • 제2권2호
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    • pp.38-44
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    • 2004
  • Theoretical and numerical studies are given to the sink flows within a rotating circular tank driven by the fluid withdrawal from a bottom circular hole. It was found that, when the upper free surface was set with no-slip boundary conditions, the Ekman boundary-layer develops not only above the bottom surface but under the top surface. The sink fluid is coming from the two Ekman layers, and the mass transfer from the bulk, inviscid region is dependent on the rotational speed. It is also remarkable to see that all the fluid gathered along the axis flows in a form of rapidly rotating fluid column haying almost the same diameter as the bottom hole.

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유체-구조 연성해석을 통한 삼각단면 형상의 비닐하우스에 관한 연구 (A study of the triangular cross section type greenhouse using fluid-structure interaction)

  • 이규한;김정재;김정주;이상준;하호진;강태원
    • 한국가시화정보학회지
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    • 제17권2호
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    • pp.17-24
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    • 2019
  • The purpose of this study is to study the fluid-dynamic and structural characteristics of the conventional greenhouse and to find possible improvement on the current greenhouse. The greenhouse is required to have enough rigidity of the structure while the installation and reinforcement should be as easy as possible. In this study, the structural stability to the snow load was tested through the computational structure analysis based on the building structure standard, and the wind load was computed by computational fluid-structure interaction analysis. The current analysis can be used as a reference data for a new greenhouse and it will be economically viable by reducing installation and maintenance costs.