• Title/Summary/Keyword: 탱크 내 격벽

Search Result 3, Processing Time 0.016 seconds

A Study of Sloshing Tank on Vessel Motions with Various Baffle Clearance (탱크 내 격벽에 의한 간극 변화가 선박 운동에 미치는 영향 연구)

  • Kim, Kyung Sung;Yu, Sunjin
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.24 no.6
    • /
    • pp.796-802
    • /
    • 2018
  • The effects of inner liquid sloshing on vessel motions are a well-known factor. It was investigated experimentally and numerically. In this regard, the study of many efforts to reduce natural phenomena of vessel motions by adopting special devices especially for roll motions. Among many devices, inserting baffles in the inner liquid tank is very common. In this study, one investigated the vessel motions with inner sloshing tanks with baffles inside. For the numerical simulation, one employed a dynamically coupled program between boundary-element-method-based vessel motion analysis program and a particle-based computational fluid dynamics program. Comparing corresponding experimental results validated the dynamically coupled program. The validated coupled program was used to simulate vessel motions, including sloshing effects with various lengths of inner baffles. The simulation results show that not only the filling ratio of inner liquid, but also the length of clearance due to baffles influenced the vessel motions. The significant point of this study was that the natural frequency of vessel motions can be maintained irrespective of the amount of filling ratio through adjustment of the clearance. In a future study, the effects of various numbers of baffles with various clearances would be conducted to percuss the possibility of vessel motion control with inner liquid sloshing effects.

Analysis of Flow Field in the Circular Water Tank According to the Number of Baffles (원형 물탱크내의 격벽수에 따른 유동장 해석)

  • Kim, Jung-Hwan;Kang, Dong-Youl;Jung, Tae-Jun;Kim, Se-Young;Choi, Jong-Wook;Chu, Byeong-Gil
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.31 no.1
    • /
    • pp.15-20
    • /
    • 2009
  • The concentration of residual chlorine should be kept at over 0.1 mg/L in the circular water tank used in a water purification system. Generally, the concentration of residual chlorine depends on the structure and the volume of water tank, and also the water flow rate. To secure the diffusion time is important to the concentration of residual chlorine. For that reason, the baffles are installed in the circular water tank. In the present study, the variations of water and chlorine concentration were obtained with time using the numerical analysis. And also, the streamlines were shown according to the number of baffles. As a results, the vortex flow appeared between baffles, and the diffusion time of chlorine increased with the more number of baffles.

Sloshing Damping in a Swaying Rectangular Tank Using a Porous Bulkhead (투과성 격벽을 이용한 수평 운동하는 사각형 탱크내의 슬로싱 감쇠)

  • Cho, Il-Hyoung
    • Journal of Ocean Engineering and Technology
    • /
    • v.32 no.4
    • /
    • pp.228-236
    • /
    • 2018
  • The performance of a porous swash bulkhead for the reduction of the resonant liquid motion in a swaying rectangular tank was investigated based on the assumption of linear potential theory. The Galerkin method (Porter and Evans, 1995) was used to solve the potential flow model by adding a viscous frictional damping term to the free-surface condition. By comparing the experimental results and the analytical solutions, we verified that the frictional damping coefficient was 0.4. Darcy's law was used to consider the energy dissipation at a porous bulkhead. The tool that was developed with a built-in frictional damping coefficient of 0.4 was confirmed by small-scale experiments. Using this tool, the free-surface elevation, hydrodynamic force (added mass, damping coefficient) on a wall, and the horizontal load on a bulkhead were assessed for various combinations of porosity and submergence depth. It was found that the vertical porous bulkhead can suppress sloshing motions significantly when properly designed and by selecting the appropriate porosity(${\approx}0.1$) and submergence depth.