• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2005년도 창립60주년 기념 추계 학술대회
• /
• pp.60.2-60.2
• /
• 2005

• 한국마린엔지니어링학회:학술대회논문집
• /
• 한국마린엔지니어링학회 2006년도 전기학술대회논문집
• /
• pp.305-306
• /
• 2006

Developed in this study is a nonlinear Ekman pumping model to be used in simulating the rotating flows with quasi-three-dimensional Navier-Stokes equations. In this model, the Ekman pumping velocity is given from the solution of the Ekman boundary-layer equations for the region adjacent to the bottom wall of the flow domain; the boundary-layer equations are solved in the momentum-integral form. The developed model is then applied to rotating flows in a rectangular container receiving a time-periodic forcing. By comparing our results with the DNS and experimental data we have validated the developed model. We also compared our results with those given from the classical Ekman pumping model. It was found that our model can predict tile rotating flows more precisely than the classical linear model.

• 한국해양공학회지
• /
• 제11권4호
• /
• pp.102-110
• /
• 1997

A two dimensional shallow-water flow around a cavity driven by a sinusoidally oscillating external flow was studied numerically with an Ekman pumping model. A container model of "T" shape was constructed in the numerical computation for comparison with the experimental observation. The material transport in the external region is in good agreement with the experimentally recorded particle trajectories. It turns out that two large coherent vortices situated in the exterior region of the cavity are responsible for clockwise and counterclockwise drift motions, in large scale, of particles. The Ekman pumping model suggested in this study was found to be satisfactory.isfactory.

• 한국해안해양공학회:학술대회논문집
• /
• 한국해안해양공학회 2001년도 한국해안해양공학발표논문집 Proceedings of Coastal and Ocean Engineering in Korea
• /
• pp.56-64
• /
• 2001

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2003년도 춘계학술대회
• /
• pp.1765-1770
• /
• 2003

This paper describes a study of the spin-up of a free-surface fluid in a rectangular container in which an internal cylindrical obstacle is mounted. Experiments and numerical analysis have been carried out for a variety of obstacle position. Increase in the speed of background rotation and near wall position of cylindrical obstacle results in the complex flow structures. Numerical and experimental results agree well with each other and the Ekman-pumping model is also applied to this flow.

• 대한기계학회논문집B
• /
• 제25권5호
• /
• pp.680-687
• /
• 2001

In this study, spin-up flows in a rectangular container are analysed both numerically and experimentally. In the numerical computation, we use two Ekman pumping models, the classical leading order and the first order. We also compared our results with those obtained for the case without a pumping model. Effect of two parameters, Reynolds number and the Rossby number on the flow evolution is studied. The first order and the leading order Ekman pumping models are in good agreement with the experimental result compared with the non-Ekman pumping model. Attention is given to the merging of two cyclonic vortices.

• 한국해안해양공학회지
• /
• 제9권4호
• /
• pp.194-200
• /
• 1997

주기적으로 요동하는 외부유동에 의해 생성되는 캐버티 주위의 2차원 천수유동은 수치적으로 연구하였다. 실험결과와 비교하기 위해 T형의 용기모델을 수치적으로 계산하여 만들었다. 수치계산에서는 캐버티의 종횡비가 전체적인 유동패턴에 크게 영향을 끼치지 않고 종횡비 2에서는 캐버티의 깊은 부분에 정체된 유동형태가 생성되는 것을 제시한다. 높은 레이놀즈 수에서 유동을 가시화 시켰을 때 나다나지 않았던 많은 와류들이 유동장을 특성화 시키고 있다. 외부지역에서의 물질전달은 실험에서 나타난 입자궤적과 잘 일치한다. 캐버티의 외부지역에 위치한 두쌍의 와류가 규모가 큰 시계방향과 반시계방향의 순환유동을 발생시키는 원인이 되는 것이 증명된 셈이다.