An Analytical Model to Predict the Environmental Forces on a Tension Leg Platform and Time Domain Response Analysis

Cornut, Stephane (1995) An Analytical Model to Predict the Environmental Forces on a Tension Leg Platform and Time Domain Response Analysis. MSc(R) thesis, University of Glasgow.

Abstract

This thesis presents a model to predict the environmental forces on a tension leg platform. The response of the platform and the loads in the mooring lines are also formulated. In the first part, the loading model to predict the forces due to waves, wind and current is developed. Chapter 2 introduces the frequency domain method used for the validation of the model. Chapter 3 presents two models for the calculation of the first order wave forces. The first one is based on a simple Morison approach, combined with the strip theory. The second model is based on analytical solutions of the diffraction and radiation wave potentials for an array of cylinders. These two methods are compared and validated with the results of a 3D diffraction radiation code. In chapter 4, two models for the calculation of second order wave loads (steady and slowly varying drift) are developed. They are based on two analytical solutions of the wave diffraction potential. The models are validated with the results of a diffraction radiation code. Chapter 5 introduces the models to predict the wind and current forces. Different formulations of wind spectra are used. The influence of the current velocity profile is investigated. In the second part, the loading model is used in time domain simulations to calculate the responses of the TLP and the forces in the tendons. Chapter 6 presents the time domain model used in this study. Different non linearities such as the free surface effects and the coupling due to the mooring system are taken into account. The effects of the non linearities are investigated for two TLP designs (Snorre and Heidrun).A comparison between a linear and a non linear model is also carried out for a whole range of wave frequencies. Finally, the effects of the directionality of the environmental forces on the tendon forces are investigated.

• Item Type: Thesis (MSc(R))
• Qualification Level: Masters
• Additional Information: Adviser: A Incecik
• Keywords: Naval engineering
• Date of Award: 1995
• Depositing User: Enlighten Team
• Unique ID: glathesis:1995-74882
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 27 Sep 2019 15:41
• Last Modified: 27 Sep 2019 15:41
• URI: https://theses.gla.ac.uk/id/eprint/74882