Modares Mechanical Engineering

Modares Mechanical Engineering

Effects of Buoy size on the frequency and time response in catenary mooring system of the semi-submersible platform

Authors
Morteza Dardel 1
Hamidreza Ghafari 2
seyed vahid sepehr mousavi 3
1 Department of Mechanical Engineering, Babol Noshirvani University of Technology, P.O. Box 484, Postal Code: 47148-71167, Shariati Street, Babol, Mazandaran, Iran. dardel@nit.ac.ir.
2 Department of Maritime Engineering, Amirkabir University of Technology, Tehran, Iran
3 amirkabir university of technology
Abstract
Due to the depletion of shallow water resources, the development of exploration and production has shifted towards the deep and ultra-deep water region. The types of floating platforms are all need to be moored when they are working as production platforms. Applying buoys to the catenary mooring system in deep water may reduce part of the weight and radius of a mooring. In this article, Dynamic responses of the Amirkabir semi-submersible platform was obtained under the combination of wind and wave loads in frequency domain and time domain simulation calculated. The JONSWAP wave spectrum and API wind spectrum are considered as environmental conditions .and also the effects of buoy size on the semisubmersible motion response is investigated. Dynamic responses of the semi-submersible platform determine by using the Morison equation and diffracting theory in AQWA ANSYS software and each dynamic mooring line is modeled as a chain of Morison-type elements subjected to various external forces. The obtained result from AQWA ANSYS in time and frequency domain shows that increasing buoy size, could increase motions of the semisubmersible platform but instead could decreasing the mooring line tension.
Keywords
Semi-submersible
buoy
catenary mooring system
three-dimensional radiation/diffraction theory
[1] T. Nakajima, S. Motora, M. Fujino, On the dynamic analysis of multicomponent mooring lines, Offshore Technology Conference, 3-6 May, Houston, Texas, 1982.
[2] S. Mavrakos, J. Chatjigeorgiou, Dynamic behaviour of deep water mooring lines with submerged buoys, Computers & Structures, Vol. 64, No. 1-4, pp. 819-835, 1997.
[3] S. Mavrakos, V. Papazoglou, M. Triantafyllou, and P. Brando, Experimental and numerical study on the effect of buoys on deep water mooring dynamics, The First International Offshore and Polar Engineering Conference, 11-16 August, Edinburgh, The United Kingdom, 1991.
[4] S. Mavrakos, V. Papazoglou, M. Triantafyllou, and J. Hatjigeorgiou, Deep water mooring dynamics, Marine Structures, Vol. 9, No. 2, pp. 181-209, 1996.
[5] W. Dongjiao, Static analysis of a wire rope-chain- buoy/sinker mooring line, China Offshore Platform, Vol. 6, pp. 003, 2007.
[6] C. Kwan, F. Bruen, Mooring line dynamics: comparison of time domain, frequency domain, and quasi-static analyses, Offshore Technology Conference, 6-9 May, Houston, Texas, 1991.
[7] S. Mazaheri, A. Incesik, Predicting the Maximum Mooring Force of a Moored Floating Offshore Structure, ASME 2004 23rd International Conference on Offshore Mechanics and Arctic Engineering, OMAE, Vol. 51245, 2004.
[8] M. A. Jordán, R. Beltrán-Aguedo, Nonlinear identification of mooring lines in dynamic operation of floating structures, Ocean Engineering, Vol. 31, No. 3, pp. 455-482, 2004.
[9] D. Garrett, Coupled analysis of floating production systems, Ocean Engineering, Vol. 32, No. 7, pp. 802-816, 2005.
[10] P. Davies, P. Baron, K. Salomon, C. Bideaud, J.-P. Labbé, S. Toumit, M. Francois, F. Grosjean, T. Bunsell, A.-G. Moysan,., Influence of fibre stiffness on deepwater mooring line response. ASME 2008 27th International Conference on Offshore Mechanics and Arctic Engineering.American Society of Mechanical Engineers, June 15–20, Vol. 1: Offshore Technology, Estoril, Portugal, 2008.
[11] C. T. Stansberg, Current effects on a moored floating platform in a sea state, 27th International Conference on Offshore Mechanics and Arctic Engineering, Vol. 4: Ocean Engineering; Offshore Renewable Energy, June 15–20, Estoril, Portugal, 2008.
[12] R. Huilong, Z. Jian, F. Guoqing, L. Hui, and L. Chenfeng, Influence of nonlinear mooring stiffness on hydrodynamic performance of floating bodies, ASME 2009 28th International Conference on Ocean, Offshore and Arctic Engineering, Vol. 1: Offshore Technology, May 31–June 5, Honolulu, Hawaii, USA, 2009.
[13] O. J. Waals, The effect of wave directionality on low frequency motions and mooring forces, Proceedings of the 28th International Conference on Ocean, Offshore and Arctic Engineering OMAE2009 31 May – 05 June, 2009, Honolulu, Hawaii, USA, Vol. 79412, pp. 31, 2009.
[14]T. Lassen, E. Storvoll, A. Bech, Fatigue life prediction of mooring chains subjected to tension and out of plane bending,ASME 2009 28th International Conference on Ocean, Offshore and Arctic Engineering, Vol. 1: Offshore Technology, Honolulu, May 31–June 5, Hawaii, USA, 2009.
[15] Z. Su-xia, T. You-gang, L. Hai-xiao, Study on snap tension in mooring lines of deepwater platform, ASME 28th International Conference on Ocean, Offshore and Arctic Engineering, Vol. 4, Ocean Engineering; Ocean Renewable Energy; Ocean Space Utilization, Parts A and B, May 31–June 5, Honolulu, Hawaii, USA, 2009.
[16] M Hosseini Manesh, M. J. Ketabdari. S. Kazemi, Investigating the behavior of suspended floating FPSO in different incident angles waves, 18th Marine Industrial Conference, Iranian Marine Engineering Society, 18 - 21 Oct. Kish Island, Iran, 2016.
[17] M. J. Ketabdari, M. Samadi, Hydrodynamic analysis of catenary mooring oil platform with cellular spars by numerical methods, 2 nd National engineering conference on construction and evaluation of civil projects, Semnan, Iran, 2015.
[18] M. J. Ketabdari, A. Shahoulaei, Analysis the behavior of semi-submersible platform with neural network, 1st Conference on strategic development of Civil, Architectural, Electrical and Mechanical of Iran, Golestan University, Golestan, Iran, 2015.
[19] The effect of catenary mooring layout on dynamic response of spar truss platform by numerical method, 18th Marine Industrial Conference, Iranian Marine Engineering Society, 18 - 21 Oct., Kish Island, 2016 .
[20] H. Parvareh, S. Jamei, A. Asvar, The effect of different incident angle of wave on ROA of different degrees of freedom of semi-submerssible Amirkabir platform 1st International conference on new research in engineerin science, Tehran, 1396.
[21] L. Xiong, J. Yang, W. Zhao, Dynamics of a taut mooring line accounting for the embedded anchor chains,Ocean Engineering, Vol. 121, pp. 403-413, 2016.
[22] O. A. Montasir, A. Yenduri, V. J. Kurian, Effect of mooring line configurations on the dynamic responses of truss spar platforms, Ocean Engineering, Vol. 96, pp. 161-172, 2015.
[23] J. Azcona, X. Munduate, L. González, and T. A. Nygaard, Experimental validation of a dynamic mooring lines code with tension and motion measurements of a submerged chain, Ocean Engineering, Vol. 129, pp.415- 427, 2017.
[24] M. Armak, A. Gharebaghi, Effect of HEAVE plates on the dynamic response of Amirkabir semi-submersible platform, International Conference on Coasts, Ports and Marine Structures, 20th November, Olympic Hotel Tehran, Iran, 2012.
[25] J. N. Newman, The theory of ship motions, Advances in Applied Mechanics, Vol. 18, pp. 221-283, 1979.
[26] W. E. Cummins, The Impulse Response Function and Ship Motions, pp. 1- 11, David Taylor Model Basin Washington DC, David W. Taylor Model Basin , 1962.
[27]J. Rashidi, H. Borhani, M. S. Seif, M. R. Fathikazeroni, Simulation and experimental investigation on the effect of heave plate on heave response of semi-submersible platform, 17th Marine Industrial Conference, 22- 25 December, Kish Island, Iran, 2015.
Modares Mechanical Engineering
Volume 18, Issue 2
April 2018
Pages 209-218