Transactions of the Korean Society of Mechanical Engineers B (대한기계학회논문집B)

The Korean Society of Mechanical Engineers (대한기계학회)
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Numerical Study on Draining from Cylindrical Tank Using Stepped Drain Port

계단형 배수구를 가진 원통 용기에서의 배수 과정에 관한 수치해석 연구

  • Son, Jong Hyeon (School of Mechanical Engineering, Kyungpook Nat'l Univ.) ;
  • Park, Il Seouk (School of Mechanical Engineering, Kyungpook Nat'l Univ.)
  • 손종현 (경북대학교 기계공학부) ;
  • 박일석 (경북대학교 기계공학부)
  • Received : 2014.05.21
  • Accepted : 2014.08.17
  • Published : 2014.12.01
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Abstract

An air-core vortex is generated during draining after stirring a rotating cylindrical tank or after filling it with water. The formation of the air-core vortex and the time of its formation are dependent on drain conditions such as the dimensions of the tank, the initial rotation or stirring speed, and the shape of the drain port. In this study, a draining process using a two-stage drain port was numerically investigated. The length and radius of the first drain stage located in the lower part of the drain port were kept constant, whereas the radius of the second drain stage was varied for simulating the draining process. The simulation was conducted by considering an axisymmetric swirling flow for all cases. The declining water level was monitored by an interface capturing method. Further, the effects of the radius of the second drain stage on the time of formation of the air-core vortex and the internal flow structure were investigated.

물이 채워진 원통 용기를 회전시킨 후 배수하면 일정시간이 지난 후 공기기둥이 발생한다. 용기의 크기, 초기 회전 속도나 교반 속도, 배수구 모양 등의 배수조건에 따라 공기기둥의 발생 여부나 발생시간이 달라진다. 본 연구에서는 2 단으로 구성된 계단형 배수구를 가진 원통 용기에서 물이 배수되는 과정을 수치해석적으로 연구하였다. 하부에 위치한 배수구 1 단은 길이와 반경이 고정되어 있고, 상부에 위치한 2 단은 길이와 반경을 변화시켰다. 2 차원 격자계에 축대칭 조건을 적용하여 원통 용기 내부의 배수유동을 해석하였다. 물과 공기의 자유표면 모양을 추적하여 수위 변화를 관찰하였으며, 배수구 2단의 형상이 공기기둥 발생시간과 내부 유동구조 변화에 미치는 영향을 확인하였다.

Keywords

References

  1. Lubin, B. T. and Springer, G. S., 1967, "The Formation of a Dip on the Surface of a Liquid Draining from a Tank," J. Fluid Mech., Vol. 29, No. 2, pp. 385-390. https://doi.org/10.1017/S0022112067000898
  2. Zhou, Q.-N. and Graebel, W. P., 1990, "Axisymmetric Draining of a Cylindrical Tank with a Free Surface," J. Fluid Mech., Vol. 221, pp. 511-532. https://doi.org/10.1017/S0022112090003652
  3. Ramamurthi, K. and Tharakan, T. J., 1996, "Flow Visualization Experiments on Free Draining of a Rotating Column of Liquid Using Nets and Tufts," Exp. Fluids., Vol. 32, No. 2, pp.139-142.
  4. Sohn, C. H., Son, J. H. and Park, I. S., 2013, "Numerical Analysis of Vortex Core Phenomenon During Draining from Cylinder Tank for Various Initial Swirling Speeds and Various Tank and Drain Port Sizes, " J. Hydrodyn. Ser. B, Vol. 25, No. 2, pp. 183-195. https://doi.org/10.1016/S1001-6058(13)60353-4
  5. Gowda, B. H. L., Joshy, P. J. and Swamamani, S., 1996, "Device to Suppress Vortexing During Draining from Cylindrical Tanks," J. Spacecr. Rockets., Vol. 33, No. 2, pp. 598-600. https://doi.org/10.2514/3.26806
  6. Gowda, B. H. L., Udhayakumar, H., 2005, "Vane-type suppressor to prevent vortexing during draining from cylindrical tanks," J. Spacecr. Rockets., Vol. 42, No. 2, pp.3881-383.
  7. Sohn, C. H., Ju, M. G. and Gowda, B. H. L., 2009, "Draining from Cylindrical Tanks with Vane-type Suppressors - A PIV Study," J. Vis., Vol. 12, No. 4, pp. 347-360. https://doi.org/10.1007/BF03181878
  8. Ramamurthi, K., Tharakan, T. J., 1992, "Shaped Discharge Ports for Draining Liquids," J. Spacecr. Rockets., Vol. 30, No. 6, pp.786-788.
  9. Sohn, C.H., Ju, M.G. and Gowda, B.H.L., 2008, "Eccentric Drain Port to Prevent Vortexing During Draining from Cylindrical Tanks, " J. Spacecr. Rockets., Vol. 45. No. 3, pp. 638-640. https://doi.org/10.2514/1.35651
  10. Hirt, C. W. and Nichols, B. D., 1981, "Volume of Fluid (VOF) Method for the Dynamics of Free Boundaries," J. Comput. Phys., Vol. 29, pp. 201-225.
  11. Patankar, S. V., 1980, Numerical Heat Transfer and Fluid Flow, McGraw-Hill, New York.
  12. Fluent 6.3 Users guide, 2006, Fluent Inc., Canonsburg.
  13. Brackbill, J.U., Kothe, D.B. and Zemach, C., 1992, "A Continuum Method for Modeling Surface Tension, " J. Comput. Phys., Vol. 100, No. 2, pp.335-354. https://doi.org/10.1016/0021-9991(92)90240-Y
  14. Park, I.S., Sohn, C.H., 2011, "Experimental and Numerical Study on Air Cores for Cylindrical Tank Draining, " Int. Commun. Heat. Mass., Vol. 38, pp.1044-1049. https://doi.org/10.1016/j.icheatmasstransfer.2011.05.002