Offshore Structures Exposed to Large Slamming Wave Loads
Doctoral thesis
Permanent lenke
http://hdl.handle.net/11250/2473020Utgivelsesdato
2017-12Metadata
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Originalversjon
Offshore Structures Exposed to Large Slamming Wave Loads by Jithin Jose, Stavanger : University of Stavanger, 2017 (PhD thesis UiS, no. 373)Sammendrag
In sloping shallow water regions, waves undergo different nonlinear transformations such as wave shoaling and breaking, due to the nonlinear wave interactions with the seabed. The forces from breaking waves are of concern for offshore structures installed in such regions. The wave breaking forces are large impulsive forces acting for short period of time. The substructures of offshore wind turbines are usually monopile, gravity-based, tripod and jackettype structures. Due to the simplicity in the design and installation, monopile structures are widely used for supporting offshore wind turbines. However, the operating water depths and turbine capacity of monopile substructures are limited. With the increase in the turbine capacity and use in larger water depths, the offshore wind industry has recently focused on rigid types of substructures, such as jackettype structures.
In order to estimate the slamming forces due to wave breaking on offshore structures, many research studies have been conducted in the past. However, most of these studies were limited to simple structures such as monopiles. The empirical force models by Goda et al. [5] and Wienke and Oumeraci [7] are widely used in the industry to estimate the breaking wave forces on monopile structures. However, in the case of the jacket structures there have not been much research. Due to the complexity of jacket structures, it is more difficult to analyse the wave forces on a jacket compared to a monopile. The empirical force models developed for approximating the slamming forces on monopiles cannot be easily transferred to jacket structures due to the different member sizes and orientations. Moreover, the uncertainties in these empirical models need to be addressed while using them for jacket structures.
In order to study breaking wave interactions with a jacket structure, high quality experimental data is required. Within the WaveSlam experiment ([4, 11]) carried out in a joint collaboration with the University of Stavanger, NTNU and the University of Hannover, a large-scale jacket structure of 1:8 scale was tested for a number of relevant breaking wave conditions. According to the author’s knowledge this is the first largescale experiment conducted to estimate the breaking wave forces on a jacket structure. This experimental dataset forms the basis for the present research. [...]
Beskrivelse
PhD thesis in Offshore technology
Består av
Paper 1: Jose, J., Podrazka, O., Obhrai, C., Gudmestad, O.T., and Cieslikiewicz, W., 2016, “Methods for Analysing Wave Slamming Loads on Truss Structures used in Offshore Wind Applications based on Experimental Data,” International Journal of Offshore and Polar Engineering, Vol. 26(2), pp. 100-108. DOI: dx.doi.org/10.17736/ijope.2016.mkr05 [Not in Brage]Paper 2: Jose, J., Podrazka, O., Gudmestad, O.T., and Cieslikiewicz, W., 2017, “Characteristics of the Wave Slamming Forces on Jacket Structures under Plunging Breaking Waves based on Experimental Data,” In the Proceedings of ASME 36th International Conference on Ocean, Offshore and Arctic Engineering (OMAE2017), Trondheim, Norway, June 25-June 30. DOI:10.1115/OMAE2017-61789 [Not available in Brage]
Paper 3: Jose, J., Podrazka, O., Gudmestad, O.T., and Cieslikiewicz, W., 2017, “Detailed Study on Breaking Wave Interactions with a Jacket Structure based on Experimental Investigations,” Journal of Offshore Mechanics and Arctic Engineering, Vol. 140(2), pp. 021301.1-021301.14. DOI: dx.doi.org/10.1115/1.4037829 [Not in Brage]
Paper 4: Jose, J., Choi, S.J., Giljarhus, K.E.T., and Gudmestad, O. T., 2017, “A Comparison of Numerical Simulations of Breaking Wave Forces on a Monopile Structure using Two Different Numerical Models based on Finite Difference and Finite Volume Methods,” Ocean Engineering, Vol. 137, 78-88. DOI: doi.org/10.1016/j.oceaneng.2017.03.045
Paper 5: Jose, J., Choi, S.J., and Gudmestad, O.T., 2017, “Sensitivity Study on a 3D Numerical Model for Estimating Breaking Wave Forces on a Jacket Structure,” In the Proceedings of 27th International Ocean and Polar Engineering Conference (ISOPE2017), San Francisco, California, June 25- June 30. ISBN: 978-1-880653-97-5. [Not available in Brage]
Paper 6: Jose, J., Choi, S.J., Lee, K.H., and Gudmestad, O.T., 2016, “Breaking Wave Forces on an Offshore Wind Turbine Foundation (Jacket Type) in the Shallow Water,” In the Proceedings of 26th International Ocean and Polar Engineering Conference, Rhodes, Greece, June 26-July 2. ISBN: 978-1-880653-88-3. [Not available in Brage]
Paper 7: Jose, J., and Choi, S.J., 2017, “Estimation of Slamming Coefficients on Local Members of Offshore Wind Turbine Foundation (Jacket Type) under Plunging Breaker,” International Journal of Naval Architecture and Ocean Engineering, Vol. 9(6), pp. 624-640. DOI: dx.doi.org/10.1016/j.ijnaoe.2017.03.006.
Utgiver
University of Stavanger, NorwaySerie
PhD thesis UiS;;373