Design of single point sub-surface deep sea moorings
TL;DR: In this paper, a finite element geometric nonlinear analysis program has been developed for the analysis of single point sub-surface deep sea moorings, where the effect of diameter of the cable, drag coefficient, rope length, current velocity, current profile and buoyancy on the mooring configuration has been studied.
About: This article is published in Ocean Engineering.The article was published on 1991-01-01. It has received 3 citations till now. The article focuses on the topics: Mooring.
Citations
More filters
TL;DR: In this article, an analytical method is developed for the solution of a typical mooring problem taking into account the presence of a subsurface buoy, and the nodal accelerations and velocities at the points of lumped mass of subsequent time steps can be expressed as per the Houbolt scheme.
Abstract: Cable-body systems are intelligent and cost-effective structures used in ocean engineering and also for many oceanographic missions. The demand for such systems is increasing steadily because of new types of systems like wind farms, ocean energy converters and floating airports. Mooring of such platforms to a fixed point on the earth makes the system secure. Dynamic behaviour of a moored system with a subsurface buoy is studied here. The optimum position of the buoy is found using an analytical approach. The location of the buoy along the cable is a critical aspect in tension reduction. An analytical method is developed for the solution of a typical mooring problem taking into account the presence of a subsurface buoy. The method originally proposed by Walten and Polachek (1959) is modified here to suit the present problem. The nodal accelerations and velocities at the points of lumped mass of subsequent time steps can be expressed as per the Houbolt scheme. Integration of the accelerations and velocities...
12 citations
TL;DR: This paper focuses on providing quantitative methodology on how each parameter affects the structural response of STLP, which will facilitate establishing the unique design criteria as regards to STLP.
Abstract: The innovative Subsurface Tension Leg Platform (STLP), which is designed to be located below Mean Water Level (M.W.L) to minimize direct wave loading and mitigate the effect of strong surface currents, is considered as a competitive alternative system to support shallow-water rated well completion equipment and rigid risers for large ultra-deep water oil field development. A detailed description of the design philosophy of STLP has been published in the series of papers and patents. Nonetheless, design uncertainties arise as limited understanding of various parameters effects on the structural response of STLP, pertaining to the environmental loading, structural properties and hydrodynamic characteristics. This paper focuses on providing quantitative methodology on how each parameter affects the structural response of STLP, which will facilitate establishing the unique design criteria as regards to STLP. Firstly, the entire list of dimensionless groups of input and output parameters is proposed based on Vaschy- Buckingham theory. Then, numerical models are built and a series of numerical tests are carried out for validating the obtained dimensionless groups. On this basis, the calculation results of a great quantity of parametric studies on the structural response of STLP are presented and discussed in detail. Further, empirical formulae for predicting STLP response are derived through nonlinear regression analysis. Finally, conclusions and discussions are made. It has been demonstrated that the study provides a methodology for better control of key parameters and lays the foundation for optimal design of STLP. The obtained conclusions also have wide ranging applicability in reference to the engineering design and design analysis aspects of deepwater buoy supporting installations, such as Grouped SLOR or TLR system.
5 citations
13 Sep 1994
TL;DR: In this paper, a dynamic finite element simulation is used to study the behavior of mooring lines in order to evaluate some tidal records made during the GASTOM 90 oceanographic mission, a non-dimensional analysis and parametric study based on a simplified mesh, allows the authors to identify the relevant parameters for the modelisation and the accurate environmental constraints used for the numerical forcing simulations.
Abstract: In order to evaluate some tidal records made during the GASTOM 90 oceanographic mission, a dynamic finite element simulation is used to study the behaviour of mooring lines. A theoretical approach, mainly a non-dimensional analysis and parametric study based on a simplified mesh, allows the authors to identify the relevant parameters for the modelisation and the accurate environmental constraints used for the numerical forcing simulations. The final results allow them to quantify, a posteriori, the expected M2 tidal signal affecting ocean on the measured area. >
2 citations
References
More filters