Andreas Kampitsis

Imperial College London | Imperial · Department of Earth Science and Engineering

The main objective of this project is to develop a precise stress analysis and modeling methodology through Finite Element Analysis (FEA) to validate the current design envelope of the oil and gas drilling platform, so as to make sure (even at the worst case scenario of 3o) that the drilling structure will not collapse below the Blow-Out-Preventer level. Towards this direction, the appropriate methodology for modeling the structural integrity of the cemented wellhead and casing system under extreme loads imported from the deepwater drilling riser has to be specifically determined. Key aspects of this methodology are the modeling of the soil and the casing-soil interaction under quasi-static conditions, as well as the modeling of the cement’s contribution to the structural system (i.e. inclusion of voids and soil-cement or cement-casing interface).

Observing the evolution of modern design of wind turbines, a trend of increasing the rotor’s diameter is recorded which naturally leads to a similar increase of the tower’s height. The numerous advantages of such a design solution arise from the facts that (i) wind energy potential is much more enhanced at greater height and increases logarithmically with respect to the distance from the ground’s surface and (ii) energy production increases in an analogous manner with the square of the blades’ length. Moreover, this trend permits the reduction of the density of wind farm positions resulting in minimization of environmental impacts. As a result, a constant increase in size of wind turbines has been recorded in recent years, with a corresponding increase in produced power, which is expected to continue in the future. Evolution of the design and manufacturing of the mechanical part has followed the increase in size and has made feasible the growing increase of power production, creating an expectation of a similar development in the upcoming years. The same evolution should also be accomplished in the design of the structural parts of wind turbines. However, increase of size has direct effects on the structural parts due to both the augmented wind pressure area and greater length. Thus, undesirable phenomena may take place and they require extensive investigation. Moreover, such large scale structures and the associated wind farms require advanced computational tools to enhance their overall performance. To address complex problems in the analysis and accurate design of the wind turbines, high-level research is conducted. The solution of the existing and emerging problems will permit the synchronized evolution of wind turbine systems as well as the formulation of a fully integrated investment proposal at the wind farm level. Meeting these objectives will increase the competitiveness of wind energy over conventional energy sources, establishing a more sustainable energy policy worldwide.