Experimental investigation on mooring loads and motions of a TLP floating wind turbine

Abstract

This paper investigates numerically and experimentally the behaviour of a Tension Leg Platform (TLP) floating wind turbine, under regular waves. The physical model tests have been performed at the Danish Hydraulic Institute (DHI) offshore wave basin. The general aim of this work is to form an accurate set of data, basically consisting in incident waves, 3D wave oscillation and mooring loads that may be used as a possible term of reference for numerical models. The paper provides a thorough description of the geometrical and dynamic characteristics of the floating body, and the results in terms of the incident waves interpreted on the basis of an array of resistive wave gauges, the displacements as observed by a tracking camera system (surge, sway, heave and roll, pitch, yaw), and the loads measured by a load cell located at the fairlead of the anchoring lines, simulating in the physical model scale the tendons characteristics in full scale. Experimental results are given in graphical form for the case of regular wave conditions. Corresponding numerical results that have been obtained using home developed software for the hydrodynamic- and the static- and dynamic-analysis of the mooring lines (HAMVAB [1] and STATMOOR [2], respectively) compare well with the experimental data. STATMOOR [2] is capable to handle the static analysis of extensible mooring lines made of several segments each of them with different geometrical properties and with attached submerged buoys along them.