Numerical simulation of nonlinear wave force on a quasi-ellipse caisson

Abstract

A three dimensional numerical model of nonlinear wave action on a quasi-ellipse caisson in a time domain was developed in this paper. Navier-Stokes equations were solved by the finite difference method, and the volume of fluid (VOF) method was employed to trace the free surface. The partial cell method was used to deal with the irregular boundary typical of this type of problem during first-time wave interaction with the structure, and a satisfactory result was obtained. The numerical model was verified and used to investigate the effects of the relative wave height H/d, relative caisson width kD, and relative length-width ratio B/D on the wave forces of the quasi-ellipse caisson. It was shown that the relative wave height H/d has a significant effect on the wave forces of the caisson. Compared with the non-dimensional inline wave force, the relative length-width ratio B/D was shown to have significant influence on the non-dimensional transverse wave force.

Keywords

quasi-ellipse caisson / wave force / VOF method / partial cell method

References

[1] Bai J., Hu J. Research on and design of new structure of elliptical caissoned pier. Journal of Port & Waterway Engineering, 2006, 395(11): 25-30

[2] Dong Z. Computation method for floating stability of elliptical caissons. Journal of Port & Waterway Engineering, 2008, 411(1): 53-59

[3] Hirt C.W., Nichols B.D. Volume of fluid (VOF) method for the dynamics of free boundaries. Journal of Computational Physics, 1981, 39: 201-225

[4] Li Y., Teng B. Wave action on maritime structures, 2002, Beijing, China: The Ocean Press, 53-56

[5] Maccamy RC, Fuchs RA (1954). Wave forces on piles: a diffraction theory. US Army Coastal Engineering Research Center, Tech. Mem., 69.

[6] Qi P. The coupled numerical model for wave actions on structures in the nearshore zone and its applications in engineering, 2001, Dalian: Dalian University of Technology, 28-29

[7] Qi P., Hou Y. A 2D/3D coupled model for wave forces on moored ships in a harbor. Journal of Hydrodynamics, Ser.B, 2004, 16(5): 633-639

[8] Ren Xiaozhong, Wang Yongxue, Wang Guoyu (2007). The wave force on the multiple quasi-ellipse caissons. Proceedings of the Fourth International Conference on Asian and Pacific Coasts, Nanjing, China, 201–208.

[9] Ren X., Wang Y., Wang G. Experimental study of wave force on multiple quasi-ellipse caisson structure. Journal of Dalian University of Technology, 2009, 49(6): 944-950

[10] Ren X., Wang Y., Wang G. The irregular wave loading on the quasi-ellipse caisson. Journal of Ship & Ocean Engineering, 2009, 38(1): 85-89

[11] Wan D., Miu G. Numerical simulations of waves overtopping an erect quadrate column. Journal of hydrodynamics, 1998, 13(3): 363-370

[12] Wang Y., Su T.C. Numerical simulation of liquid sloshing in cylindrical containers. Acta Aerodyn Sinica, 1991, 9(1): 112-119

[13] Wang Y., Zang J., Qiu D. Numerical model of cnoidal wave flume. Journal of China Ocean Engineering, 1999, 13(4): 391-398

[14] Zhu G., Ding J. Design and application of ellipsoidal caisson’s suspended rudder. Journal of China Harbour Engineering, 2007, 150(4): 61-62