Skip to main content

Experimental and Numerical Investigation of Hydrodynamic Performance of a Sloping Floating Breakwater with and Without Chain-Net

Abstract

A novel study of sloping floating breakwater (FB) that has a gap between two floaters is proposed. The slope of a structure can cause wave energy dissipation. A problem with sloping structures is wave overtopping. To solve this problem, a gap is considered between the two floaters. If overtopping occurs, water passing the crest will pour into the gap between the two floaters, as a result wave energy will be attenuated. A chain net is added to the model and its effect on the transmission coefficient is studied. Furthermore, in order to investigate the effects of the degree of freedom on the hydrodynamic performance of the structure, the model is studied in the two anchorage systems which are anchored by pile (1 degree of freedom) and anchored by mooring lines (3 degree of freedom). Moreover, the experiments are performed under regular waves with five different wave periods and four different wave heights. The results of the experiments show a sloping floating breakwater that has a better performance than that of rectangular box type by 15% as maximum value. The transmission coefficients for the FB anchored by pile are lower about 14% as maximum value than that of the FB anchored by cable in shorter waves and are higher about 4–10% in longer waves. With increasing the draft, the transmission coefficient decreases but the freeboard should meet the minimum requirements to restrict overtopping in the allowable rate. The model with a chain net exhibits a better performance as compared with the model without it by a maximum 14% reduction in the transmission coefficients.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14
Fig. 15
Fig. 16
Fig. 17
Fig. 18
Fig. 19
Fig. 20
Fig. 21
Fig. 22
Fig. 23
Fig.24
Fig. 25
Fig. 26
Fig. 27

References

  • Abul-Azm AG, Gesraha MR (2000) Approximation to the hydrodynamics of floating pontoons under oblique waves. Ocean Eng 27:365–384

    Article  Google Scholar 

  • Biesheuvel AC (2013) Effectiveness of floating breakwaters. Delf University of Technology, Dissertaion

    Google Scholar 

  • Chen Zh, Wang Y, Dong H, Zheng B (2012) Time-domain hydrodynamic analysis of pontoon-plate floating breakwater. J Water Sci Eng 5(3):291–303

    Google Scholar 

  • Daneshfaraz R, Kaya B (2008) solution of the propagation of the waves in open channels by the transfer matrix method. J Ocean Eng 35:1075–1079

    Article  Google Scholar 

  • Daneshfaraz R, Sadeghfam S, Tahni A (2020) exprimental investigation of screen as energy dissipators in the movable-Bed channel. Iran J Sci Technol Trans Civil Eng 44:1237–1246

    Article  Google Scholar 

  • Deng Zh, Wang L, Zhao X, Huang Zh (2019) Hydrodynamic performance of a T-shaped floating breakwater. J Appl Ocean Res 82:325–336

    Article  Google Scholar 

  • Dong GH, Zheng YN, Li YC, Teng B, Guan CT, Lin DF (2008) Experiments on wave transmission coefficients of floating breakwaters. Ocean Eng 35:931–938

    Article  Google Scholar 

  • Duan WY, Xu SP, Xu QL et al (2017) Performance of an F-type floating break water: a numerical and experimental study. Proc I MechE Part M 231(2):583–599

    Google Scholar 

  • Gesraha MR (2006) Analysis of π shaped floating breakwater in oblique waves: I. Impervious rigid wave boards. Appl Ocean Res 28:327–338

    Article  Google Scholar 

  • He F, Huang Zh, Wing-Keung Law A (2013) An experimental study of a floating breakwater with asymmetric pneumatic chambers for wave energy extraction. J Appl Energy 106:222–231

    Article  Google Scholar 

  • Ikeno M, Shimoda N, Iwata K (1988) A new type of breakwater utilizing air compressibility. In: Proceedings of the 21st Coastal Engineering Conference, ASCE. pp 2426–2339

  • Ji Ch, Cheng Y, Cui J, Yuan Zh, Gaidai O (2018) Hydrodynamic performance of floating breakwaters in long wave regime: an experimental study. J Ocean Eng 152:154–166

    Article  Google Scholar 

  • Koutandos E, Prinos P, Gironella X (2005) Floating breakwaters under regular and irregular wave forcing: reflection and transmission characteristics. J Hydraul Res 43(2):174–188

    Article  Google Scholar 

  • Liu Zh, Wang Y, Wang W, Hua X (2019) Numerical modeling and optimization of a winged box-type floating breakwater by Smoothed Particle Hydrodynamics. J Ocean Eng 188:106246

    Article  Google Scholar 

  • LotfollahiYaghin MA, Mojtahedi A, Aminfar MH (2012) Physical model studies and system identification of hydrodynamics around a vertical square-section cylinder in irregular sea waves. J Ocean Eng 55:10–22

    Article  Google Scholar 

  • Mansard E, Funke E (1980) The measurement of the incident and reflected spectra using the least squares method. In: Proceedings of the 17th Coastal Engineering Conference ASCE, Sydney. pp 154–172

  • Mojtahedi A, ShokatianBeiragh M, Farajpour I, Mohammadian M (2020) Investigation on hydrodynamic performance of an enviromentally friendly pile breakwater. J Ocean Eng 217:107942

    Article  Google Scholar 

  • Noroozi B, Bazargan J, Safarzadeh A (2021) Introducing the T-shaped weir: a new nonlinear weir. Water Supply. https://doi.org/10.2166/ws.2021.144

    Article  Google Scholar 

  • Pena E, Ferreras J, Sanchez-Tembleque F (2011) Experimental study on wave transmission coefficient, mooring lines and module connector forces with different designs of floating breakwaters. J Ocean Eng 38:1150–1160

    Article  Google Scholar 

  • Safarzadeh A, Zaji AH, Bonakdari H (2017) Comparative Assessment of the Hybrid Genetic Algorithm-Artificial neural network and genetic programming methods for the predicition of longitudinal velocity field around a single straight groyne. Appl Soft Comput 60:213–228

    Article  Google Scholar 

  • Tang HJ, Huang CC, Chen WM (2011) Dynamics of dual pontoon floating structure for cage aquaculture in a two-dimensional numerical wave tank. J Fluid Struct 27:918–936

    Article  Google Scholar 

  • U.S. Army coastal engineering research center (1984) Shore protection manual. U.S. Government Printing Office, Washington

    Google Scholar 

  • Williams AN, Lee HS, Huang Z (2000) Floating pontoon breakwaters. Ocean Eng 27:221–240

    Article  Google Scholar 

  • Yang Zh, Xie M, Gao Zh, Xu T, Guo W, Ji X, Yuan Ch (2018) Experimental investigation on hydrodynamic effectiveness of a water ballast type floating breakwater. J Ocean Eng 167:77–94

    Article  Google Scholar 

  • Zhang X, Ma Sh, Duan W (2018) A new L type floating breakwater derived from vortex dissipation simulation. J Ocean Eng 164:455–464

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Sahel Sohrabi.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Sohrabi, S., Lotfollahi Yaghin, M.A., Aminfar, M.H. et al. Experimental and Numerical Investigation of Hydrodynamic Performance of a Sloping Floating Breakwater with and Without Chain-Net. Iran J Sci Technol Trans Civ Eng (2021). https://doi.org/10.1007/s40996-021-00780-y

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s40996-021-00780-y

Keywords

  • Sloping floating breakwater
  • Chain net
  • Anchorage system
  • Hydrodynamic performance