International Journal of Naval Architecture and Ocean Engineering

The Society of Naval Architects of Korea (대한조선학회)
권호 표지
DOI QR코드

DOI QR Code

A numerical simulation for reduction of rudder cavitation with gap flow blocking bars

  • Oh, Jung-Keun (Jungseok Research Institute of International Logistics and Trade, Inha University) ;
  • Lee, Seung-Hee (Department of Naval Architecture & Ocean Engineering, Inha University) ;
  • Kim, Sang-Hyun (Department of Naval Architecture & Ocean Engineering, Inha University) ;
  • Seo, Dae-Won (Jungseok Research Institute of International Logistics and Trade, Inha University)
  • Published : 2012.06.30
Download PDF
⟨ Previous Next ⟩

Abstract

In recent practices, a half circular prismatic bar protruding beyond the concave surface of the horn facing the gap has been formed along the centerplane of a rudder to lessen the gap flow between the horn and the movable portion of the rudder system. If a flow through the gap of a rudder is reduced considerably through this approach, previous numerical studies indicate that not only the gap flow but also the rudder cavitation can be noticeably diminished. In the present study, numerical simulations on two-dimensional rudder sections were performed to show that the blocking ability of the single centre bar can be improved by the proper choice of sectional shape. Moreover, a pair of blocking bars attached symmetric to the centerplane on the opposite convex surface of the movable portion is suggested in the study as well, to circumvent the difficulties arising from the practical application of the single centre bars. The bars are placed near the outer edges of the gap easily accessible at the maximum rudder angle to allow simple installation of the device during a maintenance period of a ship. It is found that the pair of blocking bars further improves the blocking effects and application to a practical three-dimensional rudder also backs up the fact.

Keywords

References

  1. Boo, G.T., Song, I.H. and Shin, S.C., 2004. Numerical Simulation for the Rudder in order to Control the Cavitation Phenomena. Journal of Ship and Ocean Technology, 8(1), pp.42-50.
  2. Kim, M.C., Lee, U.S. and Byun, T.Y., 2008. Study on Optimization of Anti-erosion Rudder Section of Large Container Ship by Genetic Algorithm. Journal of the Society of Naval Architects of Korea, 45(3), pp.403-410. https://doi.org/10.3744/SNAK.2008.45.4.403
  3. Paik, B.G., Kim, K.Y., Ahn, J.W., Kim, Y.S., Kim, S.P. and Park, J.J., 2008. Experimental study on the gap entrance profile affecting rudder gap cavitation. Ocean Engineering, 35(1), pp.139-149. https://doi.org/10.1016/j.oceaneng.2007.07.013
  4. Park, K.R and Lee, Y.G., 2010. A Study on the Rudder Shapes for the Suppression of Cavitation around a Horn-type Rudder. Journal of the Society of Naval Architects of Korea, 47(4), pp.553-564. https://doi.org/10.3744/SNAK.2010.47.4.553
  5. Rhee, S.H., Lee, C.M., Lee, H.B. and Oh, J., 2010. Rudder Gap Cavitation: Fundamental Understanding and Its Suppression Devices. International Journal of Heat and Fluid Flow, 31(4), pp.640-650. https://doi.org/10.1016/j.ijheatfluidflow.2010.02.013
  6. Rhee, S.H. and Kim, H., 2008. A Suggestion of Gap Flow Control Devices for the Suppression of Rudder Cavitation. Journal of Marine Science and Technology, 13(4), pp. 356-370. https://doi.org/10.1007/s00773-008-0013-6
  7. Singhal, A.K., Athavale, M.M., Li, H. and Jiang, Y., 2002. Mathematical bases and validation of the full cavitation model. Journal of Fluid Engineering, 124(3), pp.167-264.
  8. Shen, Y.T., Jiang, C.W. and Remmers, K.D., 1997. A Twisted Rudder for Reduced Cavitation. J. Ship Research, 41(4), pp. 260-272.
  9. Seo, D.W., Lee, S.H., Oh, J.K. and Kim, H., 2010. A Numerical Study for the Efficacy of Flow Injection on the Diminution of Rudder Cavitation. International Journal of Naval Architecture and Ocean Engineering, 2(2) , pp.104-111. https://doi.org/10.3744/JNAOE.2010.2.2.104
  10. Seo, D.W., Lee, S.H., Kim. S.H. and Oh, J.K., 2012. Practically applicable devices for blocking the gap flow of a horn rudder to reduce rudder cavitation and their verification through numerical simulations. J Mar Sci Technol, 17(1) , pp.18-29. https://doi.org/10.1007/s00773-011-0149-7
  11. Guo, B., Langrish, T.A.G. and Fletcher, D.F., 2001. Simulation of turbulent swirl flow in an axisymmetric sudden expansion. AIAA journal, 39(1). pp.96-102. https://doi.org/10.2514/2.1275