• Title/Summary/Keyword: viscous

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SLOW VISCOUS FLOW PAST A CAVITY WITH INFINITE DEPTH

  • Kim, D.W;Kim, S.B;Chu, J.H
    • Journal of applied mathematics & informatics
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    • v.7 no.3
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    • pp.801-812
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    • 2000
  • Two-dimensional slow viscous flow on infinite half-plane past a perpendicular infinite cavity is considered on the basis of the Stokes approximation. Using complex representation of the two-dimensional Stokes flow, the problem is reduced to solving a set of Fredholm integral equations of the second kind. The streamlines and the pressure and vorticity distribution on the wall are numerically determined.

SENSITIVITY ANALYSIS OF A SHAPE CONTROL PROBLEM FOR THE NAVIER-STOKES EQUATIONS

  • Kim, Hongchul
    • Korean Journal of Mathematics
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    • v.25 no.3
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    • pp.405-435
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    • 2017
  • We deal with a sensitivity analysis of an optimal shape control problem for the stationary Navier-Stokes system. A two-dimensional channel flow of an incompressible, viscous fluid is examined to determine the shape of a bump on a part of the boundary that minimizes the viscous drag. By using the material derivative method and adjoint variables for a shape sensitivity analysis, we derive the shape gradient of the design functional for the model problem.

Code Development for Analysis of 2D Viscous Flow with Free Surface (2차원 자유표면 점성 유동 계산 코드 개발에 관한 연구)

  • Huh J. S.;Sah J.-Y.
    • 한국전산유체공학회:학술대회논문집
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    • 1998.05a
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    • pp.162-167
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    • 1998
  • A computer code has been developed for the analysis of 2D viscous flow with free surface. VOF method and higher order upwind scheme have been employed for the accurate prediction of free surface motion. Surface tension effect and axisymmetric flow can be computed by the present code.

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Numerical Study of Flow Characteristics of Marine Propeller (수중 프로펠러의 유동특성에 관한 수치적 연구)

  • Kim Yong-Moon;Jang Jin-Ho;Park Warn-Gyu
    • 한국전산유체공학회:학술대회논문집
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    • 2002.10a
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    • pp.139-143
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    • 2002
  • The purpose of this paper is to develop the CFD code to consider the viscous flow features of the marine propeller. The flow of the marine propeller has been numerically analyzed by using three dimensional viscous incompressible Navier-Stokes equation. The model used in this study is Screw B with 4 blades whose pitch ratio is 1 in Ka-4-55 screw series. The result of the analysis was compared with panel method.

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A study on the spreading of an oil slick under the influence of gravitational and viscous forces (중력-점성력에 의한 유출유 퍼짐에 관한 연구)

  • 김창제;채양범
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.3 no.2
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    • pp.63-67
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    • 1997
  • In this study, some approximate theoretical solutions about oil spreading under the influence of gravitational and viscous forces have been derived from the viewpoint of energy conservation. The theoretical model which derived newly is in agreement with Toi's one derived from a different hypothesis, and shown to predict well the spreading distance of oil front at an initial step of outflow, but further study is necessary to evaluate the spreading distance after longer time.

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Simulation of Viscous Flow around a Circular Cylinder between Parallel Walls

  • Kwag, Seung-Hyun
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2002.10a
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    • pp.212-216
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    • 2002
  • 평행한 벽 내부의 흐르는 규제 속에 원형실린더를 놓고 운동장 해석을 수행하였다. 비압축성 Navier- Stokes 방정식을 풀었고 3차 풍상미분의 수치해법을 이용하였다. 채널 내부에서 실린더의 위치를 이동하면서 벽면의 효과 전단력, 와류의 현장을 규명하였다. 수치처리는 Marker & Cell 기법에 의한 유한차분법을 사용하였다. 본 연구를 통하여 실린더와 벽 경계 사이에서의 생성된 와가 박리 전단에 영향을 미치는 것을 알 수 있었다.

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Hall Effect on Unsteady Hartmann Flow with Heat Transfer Under Exponential Decaying Pressure Gradient

  • Attia Hazem A.
    • Journal of Mechanical Science and Technology
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    • v.20 no.8
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    • pp.1302-1308
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    • 2006
  • The unsteady Hartmann flow of an electrically conducting, viscous, incompressible fluid bounded by two parallel non-conducting porous plates is studied with heat transfer taking the Hall effect into consideration. An external uniform magnetic field and a uniform suction and injection are applied perpendicular to the plates while the fluid motion is subjected to an exponential decaying pressure gradient. The two plates are kept at different but constant temperatures while the Joule and viscous dissipations are included in the energy equation. The effect of the ion slip and the uniform suction and injection on both the velocity and temperature distributions is examined.

Computational Analysis of 3-Dimensional Viscous Flow within Centrifugal Compressors (원심압축기 내부유동의 점성 3차원 해석)

  • Park, Mu-Ryong;Choe, Beom-Seok;Yun, Ui-Su
    • 연구논문집
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    • s.24
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    • pp.107-117
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    • 1994
  • In aerodynamic design of centrifugal compressors, impellers are designed through preliminary design and blade profile generation. In order to find out faults of the initially designed impellers, the detailed informations about internal flow phenomena such as pressure distribution, flow separation, blade loading, etc are essential. These informations can be acquired with flow measurements or computational flow analyses. In this study, we calculated 3-D viscous flow in 4 back-swept impellers which were designed in our laboratory, and analyzed the flow characteristics which influence the performance of impellers.

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Optimum Design of Viscous Torsional Vibration Damper Using Random Tabu Search Method (Random Tabu 탐색법을 이용한 점성 비틀림 진동감쇠기의 최적설계)

  • 김유신;양보석
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1996.10a
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    • pp.301-306
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    • 1996
  • A torsional damper is generally used to reduce the torsional vibration which occurs at a crankshaft of a multi-cylinder high speed diesel engine. Vibration amplitude should be estimate by the appropriate simulation model to determine the optimum specifications of damper. In this paper a new method which was based on the random tabu search method(RTSM) would be introduced for the viscous damper design to optimize the damping performance. The result was ascertained by comparing with conventional rubber damper.

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