Design Optimization of Wake Equalizing Duct Using CFD

CFD를 이용한 Wake Equalizing Duct의 최적설계

  • Received : 2010.12.29
  • Accepted : 2011.08.16
  • Published : 2011.08.31


In this paper, wake equalizing duct (WED) form optimization was carried out using computational fluid dynamics (CFD) techniques. A WED is a ring-shaped flow vane with a foil-type cross-section fitted to a hull in front of the upper propeller area. The main advantage of a WED is the power savings resulting from the uniformity of the velocity distribution on the propeller plane, a reduction in the flow separation at the aft-body, and lift generation with a forward force component on the foil section. This paper intends to evaluate these functions and find an optimized WED form for minimizing the viscous resistance and equalizing the wake distribution. In the optimization process, the study uses four WED parameters: the angle of the section, longitudinal location, and angles of the axes for the half rings against the longitudinal and transverse planes of the ship. KRISO 300K VLCC2 (KVLCC2) is chosen as an example ship to demonstrate the WED optimization. The optimization procedure uses genetic algorithms (GAs), a gradient-based optimizer for the refinement of the solution, and Non-dominated Sorting GA-II(NSGA-II) for Multiobjective Optimization. The results show that the optimized WED can reduce the viscous resistance at the expense of the uniformity of the wake distribution.


Wake equalizing duct;Computational fluid dynamics;Optimum design


  1. 김희정, 전호환, 안남현 (2008). "전역 최적화기법과 파라메트릭 변환함수를 이용한 선형 최적화", 대한조선학회 논문집, 제45권, 제6호, pp 590-600.
  2. 양해욱, 김병남, 유재훈, 김우전 (2010). "CFD를 이용한 모형선과 실선 스케일의 반류 비교", 대한조선학회 논문집, 제47권 제2호, pp 150-162.
  3. 이춘주. 박일룡, 이영연 (2004). "DWT 40,000톤급 정유운반선에 부착한 Vortex Generator에 대한 유체특성 연구", 대한조선학회 추계학술대회논문집, pp 257-263.
  4. 이현승, 최영복 (2009). "반류제어장치의 선박성능요소에 미치는 영향에 대한 고찰" 대한조선학회 논문집, 제46권, 제5호, pp 453-459.
  5. 임채성, 박동우 (2007). "컨테이너 운반선의 선미부가물에 의한 속도성능 향상에 대한 연구" 대한조선학회 특별논문집, pp 32-42.
  6. Broadley, I. and Garry, K. (1997). Effectiveness of Vortex Generator Position and Orientation on Highly Swept Wings, AIAA-97-2319.
  7. Fahri, C. (2007). "A numerical study for effectiveness of a wake equalizing duct", Ocean Engineering 34, pp 2138-2145.
  8. Schneekluth, H. and Bertram, V. (1987). Ship Design for Efficiency and Economy, Btterqorth-Heinemann Ltd, Linacre House, Jordan Hill, Oxford.
  9. Hino T. (2005). Proc. of CFD Workshop Tokyo 2005, Tokyo, Japan.
  10. Schittkowski, K. (1985/86). "NLPQL: A FORTRAN subroutine solving constrained nonlinear programming problems", Annals of Operations Research, Vol 5, pp 485-500.
  11. Wendt, B.J. and Reichert, B.A. (1996). The Modelling of Symmetric Airfoil Vortex Generators, AIAA Paper 96-0807.


Grant : 지역혁신인력양성사업