Journal of Marine Science and Technology

, Volume 19, Issue 3, pp 314–326 | Cite as

A parametric study on water-entry of a twin wedge by boundary element method

  • Reza Yousefnezhad
  • Hamid Zeraatgar
Original article


High speed catamarans are used for pleasure, racing as well as passenger transportations. Optimal design of these crafts requires knowledge of sea loads exerted on their structures. The total load may be estimated by integration of loads exerted on a series of two-dimensional sections along the hull. In order to access the cross-sectional loads, the problem may be simplified to solve the water-entry problem of a twin hull. In this paper, water-entry problem of a twin wedge at constant vertical water-entry speed is studied. The problem is solved in the framework of potential theory using boundary element method where gravity effect on the flow is neglected. A simplified model based on Wagner theory is employed. Free surface elevation and pressure distribution on the body in different deadrise angles have been evaluated. A parametric study has been done to investigate effects of deadrise angle, distance between demi-hulls and free surface elevation on maximum pressure coefficient. Finally, a regression formula for maximum pressure coefficient has been proposed. Results of parametric study reveal that as time advances the interaction between two demi-hull gets more severe, besides the interaction effect on pressure coefficient is nonlinear.


Catamaran Water-entry Boundary element Parametric study 


  1. 1.
    Von Karman T (1929) The impact of seaplane floats during landing. NACA TN 321, October, Washington, DCGoogle Scholar
  2. 2.
    Wagner H (1932) The phenomena of impact and planning on water. National Advisory Committee for Aeronautics, Translation 1366, Washington, DC ZAMM. Journal of Applied Mathematics and Mechanics 12(4): 193–215Google Scholar
  3. 3.
    Zhao R, Faltinsen OM (1993) Water entry of two-dimensional bodies. J Fluid Mech 246:593–612CrossRefMATHGoogle Scholar
  4. 4.
    Zhao R, Faltinsen OM, Aarsnes J (1996) Water entry of arbitrary two dimensional sections with and without flow separation. In: 21st Symposium on Naval Hydrodynamics, Tronheim, Norway, National Academy Press, Washington, DCGoogle Scholar
  5. 5.
    Zhao R, Faltinsen OM (1998) Water entry of arbitrary axisymmetric bodies with and without flow separation. In: 22nd Symposium on Naval Hydrodynamics, Washington, DCGoogle Scholar
  6. 6.
    Faltinsen OM (2002) Water entry of a wedge with finite deadrise angle. J Ship Res 46(1):39–51Google Scholar
  7. 7.
    Faltinsen OM, Landrini M, Greco M (2004) Slamming in marine applications. J Eng Math 48(3–4):187–217CrossRefMATHGoogle Scholar
  8. 8.
    Whelan JR (2004) Wetdeck slamming of high speed catamarans with a centrebow. Ph.D. Thesis, University of TasmaniaGoogle Scholar
  9. 9.
    Davis MR, Whelan JR (2007) Computation of wet deck bow slam loads for catamaran arched cross sections. Ocean Eng 34(17–18):2265–2276CrossRefGoogle Scholar
  10. 10.
    Wu GX (2006) Numerical simulation of water entry of twin wedges. J Fluids Struct 22:99–108CrossRefGoogle Scholar
  11. 11.
    Mei X (1998) On the impact of arbitrary two-dimensional sections. M.Sc. Thesis, Massachusetts Institute of TechnologyGoogle Scholar
  12. 12.
    Mei X, Liu Y, Yue DKP (1999) On the water impact of general two-dimensional sections. Appl Ocean Res 21:1–15CrossRefGoogle Scholar
  13. 13.
    Greco M (2001) A two-dimensional study of green-water loading. Ph.D. Thesis, Norwegian University of Science and TechnologyGoogle Scholar
  14. 14.
    Sun H (2007) A boundary element method applied to strongly nonlinear wave-body interaction problems. Ph.D. Thesis, Norwegian University of Science and TechnologyGoogle Scholar

Copyright information

© JASNAOE 2014

Authors and Affiliations

  1. 1.Faculty of Marine TechnologyAmirkabir University of TechnologyTehranIran

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