Dynamic analysis of a tension leg platform under extreme waves
Keywords:TLP, Extreme waves, wave directionality, long crest sea waves, dynamic response
Recent observations of the sea state that result in the undesirable events confirm the presence of extreme waves like freak waves, which is capable of causing irreparable damages to offshore installations and (or) create inoperable conditions to the crew on board. Knowledge on the extreme wave environment and the related wave-structure interaction are required for safer design of deep-water offshore structures. In the current study, typical long crested extreme waves namely: i) New Year wave at offshore Norway; and ii) Freak wave at North Sea are simulated using the combined wave model. Dynamic response of the Tension Leg Platforms (TLP) under these extreme waves is carried out for different wave approach angles. Based on the analytical studies cared out, it is seen that the TLPs are sensitive to the wave directionality when encountered by such extreme waves; ringing type response is developed in TLPs which could result in tether pull out.
Anita Joseph, Lalu Mangal and Precy Sara Gorge. (2009): Coupled dynamic response of three-columned mini TLP, Journal of Naval Arch and Marine Engineering, Vol. 6, No. 2, pp. 52-61. doi: 10.3329/jname.v6i2.2789
Chandrasekaran S, Gaurav, G. Serino and S. Miranda (2011): Ringing and springing response of triangular TLPs, International Shipbuilding Progress, Vol. 58, pp. 141163., doi:10.3233/ISP-2011-0073
Chandrasekaran S and A.K. Jain (2002): Dynamic behaviour of square and triangular tension leg platforms under regular wave loads, Ocean Engineering, Vol. 29, No. 3, pp. 279313. http://dx.doi.org/10.1016/S0029-8018(00)00076-7,
Chandrasekaran S and A.K. Jain (2002): Triangular configuration tension leg platform behaviour under random sea wave loads, Ocean Engineering, Vol. 29, No. 15, pp. 18951928, http://dx.doi.org/10.1016/S0029-8018(01)00111-1,
Chopra A.K. (2003): Dynamics of structures: theory and applications to earthquake engineering. Pearson Education, 2nd Ed., Singapore, ISBN81-7808-472-4
Clauss G.F., C.E. Schmitter and K. Stutz (2003): Freak wave impact on Semisubmersibles Time-domain Analysis of Motions and Forces, Proc. 13th International Offshore and Polar Engineering Conf., Honolulu, USA, JSC-371.
Didenkulova, I.I., A.V. Slunyaev, E.N. Pelinovsky and C. Kharif (2006): Freak waves in 2005, Journal of Natural Hazards and Earth System Sciences, Vol. 6, pp. 1007-1015, doi:10.5194/nhess-6-1007-2006
Christian Kharif, C and Efim Pelinovsky (2003): Physical mechanisms of the rough wave phenomenon, European Journal of Mechanical B Fluids, Vol. 22, pp. 603-634, http://dx.doi.org/10.1016/j.euromechflu.2003.09.002,
Kriebel, D.L. (2000): Efficient simulation of extreme waves in a random sea, Rogue Waves 2000 Workshop, Brest, pp. 29-39.
Liu, P C. (2007): A cchronology of freque wave encounters, Journal of Geofizika, Vol. 24, No. 1, pp. 5770.
Rajesh Kannah, T. and R. Natarajan (2006): Effect of turret location on the dynamic behaviour of internal turret moored FPSO system, Journal of Naval Arch and Marine Engineering, Vol. 3, No. 1, pp. 23-37, doi:10.3329/jname.v3i1.92.
Srinivasan Chandrasekaran and Subrata Kumar Bhattacharyya. 2012: Analysis and Design of Offshore Structures with illustrated examples, Human Resource Development Center for Offshore and Plant Engineering (HOPE Center), Changwon National University Press, Republic of Korea ISBN: 978-89-963915-5-5, pp. 285.
Zanqiang. L., Z. Ningchuan and Y.U. Yuxiu (2011): An efficient focusing model for generation of freak waves, Journal of Acta Oceanol, Vol. 30, No. 6, pp. 19-26.
Zhao X, S. Zhaochen and L. Shuxiu (2009): Efficient focusing models for generation of freak waves. Journal of China Ocean Engineering, Vol. 23, No. 3, pp. 429-440.