Hydrodynamic Difference of Rectangular-Box Systems with and without Narrow Gaps
Publication: Journal of Engineering Mechanics
Volume 141, Issue 8
Abstract
To analyze the hydrodynamic difference between marine structures with and without narrow gaps, a two-dimensional fully nonlinear time-domain numerical wave flume is developed to investigate the hydrodynamics around multiple rectangular-box structures close to one another in waves. In the numerical model, the incident waves are generated by inner-domain sources such that re-reflection at the input boundary can be avoided. The fully nonlinear kinematic and dynamic boundary conditions are satisfied for the instantaneous free surface, and artificial damping is used for the free surface in the gaps to model the viscous effect. The proposed model is first validated against the experimental data for an isolated box and twin- and triple-box systems with narrow gaps. Then extensive numerical experiments are performed to compare the wave heights and wave loads on rectangular boxes with and without narrow gaps. The first comparison is made between the hydrodynamics of each individual box of a multiple-box system and those of an isolated box. The numerical investigation shows that the wave loads on each box in a multiple-box system are greater than those on an isolated box near the resonant wave frequency. Next the hydrodynamics for a multiple-box system are compared with those for a single-monolithic-box system with a total length equal to that of the entire multiple-box system. It is found that the wave height on the weather side of a multiple-box system at resonance is smaller than that of a single-monolithic-box system, and it decreases as the number of gaps increases. The opposite trend is found for the wave height on the lee side.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
The authors acknowledge the financial support of the National Natural Science Foundation of China (Grant Nos. 51179028, 51222902, 51221961), the Program for New Century Excellent Talents in University (Grant No. NCET-13-0076), and the Joint Project between NSFC and RSE (Grant No. 512111272).
References
Brorsen, M., and Larsen, J. (1987). “Source generation of nonlinear gravity waves with the boundary integral equation method.” Coastal Eng., 11(2), 93–113.
Chen, X. B. (2005). “Hydrodynamic analysis for offshore LNG terminals.” 2nd Int. Workshop on Applied Offshore Hydrodynamics-LabOceano, COPPE/UFRJ, Rio de Janeiro, Brazil.
Dubrovsky, V. A., and Lyakhovitsky, A. G. (2001). Multi-hull ships, Backbone Publishing, Fair Lawn, NJ.
Elchahal, G., Younes, R., and Lafon, P. (2008). “The effects of reflection coefficient of the harbour sidewall on the performance of floating breakwaters.” Ocean Eng., 35(11-12), 1102–1112.
Ertekin, R. C., and Kim, J. W. (1999). “Hydroelastic response of floating mat-type structure in oblique, shallow-water waves.” J. Ship Res., 43(4), 241–254.
Faber, F., Bliault, A. E. J., Resweber, L. R., and Jones, P. S. (2002). “Floating LNG solutions from the drawing board to reality.” Offshore Technol. Conf., Houston, TX.
Faltinsen, O. M., Rognebakke, O. F., and Timokha, A. N. (2007). “Two-dimensional resonant piston-like sloshing in a moonpool.” J. Fluid Mech., 575, 359–397.
Iwata, H., Saitoh, T., and Miao, G. P. (2007). “Fluid resonance in narrow gaps of very large floating structure composed of rectangular modules.” Proc., 4th Int. Conf. on Asian and Pacific Coasts, China Ocean Press, Beijing, 815–826.
Kim, Y. W. (2003). “Artificial damping in water wave problems I: Constant damping.” Int. J. Offshore Polar Eng., 13(2), 88–93.
Koo, W. C., and Kim, M. H. (2004). “Freely-floating body simulation by a 2D fully nonlinear numerical wave tank.” Ocean Eng., 31(16), 2011–2046.
Koo, W. C., and Kim, M. H. (2007). “Fully nonlinear wave-body interactions with surface-piercing bodies.” Ocean Eng., 34(7), 1000–1012.
Kristiansen, Y., and Faltinsen, O. M. (2009). “Studies on resonant water motion between a ship and a fixed terminal in shallow water.” J. Offshore Mech. Arct. Eng., 131(2), 021102.
Lu, L., Cheng, L., Teng, B., and Zhao, M. (2010). “Numerical investigation of fluid resonance in two narrow gaps of three identical rectangular structures.” Appl. Ocean Res., 32(2), 177–190.
Lu, L., Teng, B., Cheng, L., Sun, L., and Chen, X. B. (2011). “Modelling of multi-bodies in close proximity under water waves—Fluid resonance in narrow gaps.” Sci. China Phys. Mech. Astron., 54(1), 16–25.
Miao, G. P., Ishida, H., and Saitoh, T. (2000). “Influence of gaps between multiple floating bodies on wave forces.” China Ocean Eng., 14(2), 407–422.
Newman, J. N. (1974). “Interaction of water waves with two closely spaced vertical obstacles.” J. Fluid Mech., 66(1), 97–106.
Ning, D. Z., Teng, B., Eatoack, T. R., and Zang, J. (2008). “Numerical simulation of non-linear regular and focused waves in an infinite water-depth.” Ocean Eng., 35(8-9), 887–899.
Saad, Y., and Schultz, M. H. (1986). “GMRES: A generalized minimal residual algorithm for solving nonsymmetrical linear systems.” SIAM J. Sci. Stat. Comput., 7(3), 856–869.
Saitoh, T., Miao, G. P., and Ishida, H. (2006). “Theoretical analysis on appearance condition of fluid resonance in a narrow gap between two modules of very large floating structure.” Proc, 3rd Asia-Pacific Workshop on Marine Hydrodynamics, China Ocean Press, Beijing, 170–175.
Sun, L., Taylor, P. H., and Eatock Taylor, R. (2010). “First- and second-order analysis of resonant waves between adjacent barges.” J. Fluids Struct., 26(6), 954–978.
Tanizawa, K. (1996). “Long time fully nonlinear simulation of floating body motions with artificial damping zone.” Soc. Nav. Architects Jpn., 1996(180), 311–319.
Teh, H. M., and Ismail, H. (2013). “Hydraulic characteristics of a stepped-slope floating breakwater.” 4th Int. Conf. Energy Environment (ICEE), Selangor, Malaysia.
Wang, C. M., and TayVery, Z. Y. (2011). “Large floating structures: Applications, research and development.” 12th East Asia-Pacific Conf. Structural Engineering and Construction, Hong Kong, 62–72.
Yan, S., Ma, Q. W., and Chen, X. (2009). “Fully nonlinear hydrodynamic interaction between two 3D floating structures in close proximity.” Proc, Int. Offshore and Polar Eng. Conf., Osaka, Japan, 662–670.
Yoon, J. S., and Cho, S. P., Jiwinangun, R. G., and Lee, P. S. (2014). “Hydroelastic analysis of floating plates with multiple hinge connections in regular waves.” Marine Struct., 36, 65–87.
Tajali, Z., and Shafieefar, M. (2011). “Hydrodynamic analysis of multi-body floating piers under wave action.” Ocean Eng., 38(17–18), 1925–1933.
Zhao, W. H., Yang, J. M., and Hu, Z. Q. (2012). “Hydrodynamic interaction between FLNG vessel and LNG carrier in side by side configuration.” J. Hydrodyn., 24(5), 648–657.
Information & Authors
Information
Published In
Copyright
© 2015 American Society of Civil Engineers.
History
Received: Sep 17, 2014
Accepted: Jan 20, 2015
Published online: Apr 28, 2015
Published in print: Aug 1, 2015
Discussion open until: Sep 28, 2015
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.