Analysis of Three-dimensional Water Waves Created by a Hydrofoil Using a Higher-Order Boundary Element Method

고차경계요소법을 이용한 수중익에 대한 3차원 조파문제 해석

  • 박일룡 (부산대학교 조선해양공학과 대학원) ;
  • 전호환 (부산대학교 조선해양공학과(기계기술연구소)) ;
  • 김성환 (부산대학교 조선해양공학과 대학원) ;
  • 하동대 (부산대학교 조선해양공학과(기계기술연구소))
  • Published : 1998.08.01

Abstract

In the present paper, the hydrodynamic characteristics of three dimensional hydrofoils moving with a constant speed below the free surface using a higher-order boundary element method based on 9-node Lagrangian curvilinear elements are investigated. A bi-quadratic spline scheme is employed to improve the numerical results on the free surface. To validate the present scheme, the calculated results are compared with the analytic solutions for a submerged sphere and a spheroid showing a good agreement. For the validation of the hydrofoil study, the computed lift and drag of a hydrofoil having $NACA64_{1}A412$ section with aspect ratio(A.R.) of 4 are compared with the experimental data by Wadlin et al.[28]. The comparison covers a number of variations of angle of attack and submergence depth. Then, using an A.R. hydrofoil with NACA0012 section, the free surface on the lift and drag are investigated and these are compared with the previous results. The wave elevations and patterns created by the aforementioned submerged bodies are also investigated with Froude numbers and submergences.

본 논문에서는 9절점 라그란지안(Lagrangian) 곡면요소를 바탕으로 한 고차경계요소법(Higher-order Boundary Element Method)을 사용하여 자유수면 아래에서 일정한 속도로 전진하는 3차원 수중익에 대한 유체역학적 특성을 연구하였다. 수치계산법에 있어서 자유수면의 계산결과를 개선하기 위해 겹2차 스플라인(bi-quadratic spline)기법을 도입하였다. 수치기법의 검증에서 잠수된 구와 구형체에 대한 해석해와 수치계산 결과가 잘 일치함을 볼 수 있었다. 수중익 문제에 대한 적용성과 그 타당성을 검증하기 위해서 가로-세로비(aspect ratio; A.R.)가 4인 NACA641A412 단면을 가신 3차원 수중익 주위 유동을 해석하였다. 속도가 일정할 때 받음각(angle of attack)과 잠수깊이 변화에 따른 Wadlin et al.[28]의 양력과 항력 계측 실험결과와 비교하였으며, 각각의 경우에 대해 본 수치계산 결과들이 실험결과와 비교적 잘 일치하는 것을 볼 수 있었다. 가로-세로비 4의 NACA0012단면을 가지는 수중익에 대한 계산결과에서는 수중익에 작용하는 양력과 항력에 미치는 자유수연의 영향을 고찰하였으며, 서로 다른 속도와 잠수깊이에서 수중익에 의해 발생하는 자유수면의 변위변화를 고찰하였다.

Keywords

References

  1. ZAHI Rep. v.311 Approximative Hydrodynamic Calculation of a Hydrofoil of finite Span Wladimirow A
  2. NACA Wartime Rept. Characteristics of an NACA 66,S-209 Section Hydrofoil at Several Depths Land N. S.
  3. NACA Wartime Rept. An Investigation of Hydrofoils in the NACA Tank Benson J. M;Land N. S.
  4. NACA Wartime Rept. Preliminary Tests in th NACA Tank to Investigate the Fundamental Characteristics of Hydrofoils Ward K. E;Land N. S.
  5. Deutsche Versuchsanstalt fuer Luffahrt e. v., Hamburg,Bericht Nr. 408/1 Experimentalle Untersuchungen zur Frage des Wassertragfluegels Sottorf W.
  6. Journal of Fluid Mechanics v.26 The Breaking and Non-breaking Wave Resistance of a Two Dimensional Hydrofoil Duncan J. H.
  7. Journal of Applied Physics v.27 no.3 Pressure distribution on a Hydrofoil Running near the Water Surface Parkins G. R;Perry B;Wu;T. Y.
  8. Proc. of the Annual Spring Meeting,The Society of Naval Architects of Korea Systematic Studies on the Development and the Estimation of Hydrodynamic Characteristics of New Hydrofoil Sections Moving under the Free Surface Min K. S;Lee H. G.
  9. Journal of Fluid Mechanics v.28 Potential Flow About Two-Dimensional Hydrofoils Giesing J. P;Smith A. M. O.
  10. Journal of Ship Reseach v.13 Froude Number Effects on Two-Dimensional Hydrofoils Hough G. R.;Moran J. P.
  11. Journal of Fluid Mechanics v.37 On Higher-Order Wave Theory for Submerged Two-Dimensional Bodies Salvesen;N.
  12. Proc. of the Annual Srping MEeting, The Society of Naval Architects of Korea Analysis of 2-D Nonlinear Wave Problem using Rankine Source Panel method Park I. R.;Chun H. H.;Chung J. H.
  13. Journal of Hydrospace Technology v.1 no.2 A Nonlinear Calculation of 2-Dimensional Hydrofoil with Shallow Submergence Lee;S. J.
  14. Journal of Hydrospace Technology v.1 no.2 Study on the Flow Characteristics around a Hydrofoil including Free-Surface Effects Kim W. J;Van S. H.
  15. Transactions of the Society of Naval Architects of Korea v.32 no.3 Numerical Computation of Viscous Flow around an Advancing Hydrofoil under Free Surface Park J. J;Choi K. H;Jeong S. M;Lee Y. G.
  16. Journal of mathematics and Physics v.33 A Theory for Hydrofoils of Finite Span Wu T. Y.
  17. Journal of Ship Research v.2 no.1 Application of Ship-Wave Theory to the Hydrofoil of Finite Span Breslin J. P.
  18. Advances in Hydroscience v.3 Linearized Steady Theory of Fully Wetted Hydrofoils Nishiyama T.
  19. 19th Symposium on Naval Hydrodynamics A Localized Finite-Element Method for Nonlinear Free-Surface Wave Problems Bai K. J.;Lee H. K.
  20. Transactions of the Weat-japan Society of Naval Architects v.76 Calculation of the Hydrodynamic Forces Acting on a Hydrofoil Nakatake K;Kawagoe T;kataoka K;Ando J.
  21. Transactins of the Society of Naval Architects of Korea v.32 no.1 Analysis of Steady and Unsteady Flow Around a Ship Using a Higher-Order Boundary Element Method Hong S. Y.;Choi H. S.
  22. Ph.D.dissertation,Texas A&M University Application of Higher Order Boundary Element Method to Steady Ship Wave Problem and Time Domain Simulation of Nonlinear Gravity Waves Boo;S. Y.
  23. International Journal for Numerical methods in Engineering v.24 A Self-Adaptive Co-ordinate Transformation for Efficient Numerical Evaluation of General Boundary Element Integrals Tells J. C. F.
  24. 17th Symposium on Naval Hydrodynamics Stability Analysis of Panel methods for Free-Surface Flows with Forward Speed Sclavounos;P. D;Nakos;D. E
  25. Ph.D. dissertation, Department of Ocean Engineering, M.I.T.,Cambidge,Mass A Potential-based Panel method for the Analysis of Marine Propellers in Steady Flow Lee J. T.
  26. 60th Anniversary Series.The Society of naval Architects of japan v.2 On the Wave Resistance of a Submerged Body Bessho M.
  27. Journal of Ship Research v.31 no.4 Convergence Properties of the Nuumann-Delvin Problem for a Submerged Body Doctors L. J.;Beck R. F.
  28. NACA RML52D23a A Theoretical and Experimental Investigation of the Lift and Drag Characteristics of a Hydrofoil at. Subcritical and Supercritical Speeds Wadin K. L;Shuford C. L. Jr.;Megehee J. R.
  29. Boundary Element Techniques Brebbia C. A;Telles J. C. F;Wrobel L. C.