| Abstract |
The Performance Assessment of Wave and Tidal Array Systems (PerAWaT) project, launched in October 2009 with £8m of ETI investment. The project delivered validated, commercial software tools capable of significantly reducing the levels of uncertainty associated with predicting the energy yield of major wave and tidal stream energy arrays. It also produced information that will help reduce commercial risk of future large scale wave and tidal array developments.
This deliverable details the simulation results and experimental data for the wave calibration tests and device performance tests involving focused wave groups, a subset of the large array testing programme conducted as outlined in WG2 WP2 D1. The numerical reconstruction of the fully nonlinear incident focussed waves from measured wave probe data is demonstrated as part of the simulation of the wave calibration tests.The nonlinear PTO force implemented in the experimental tests is modelled using a similar approach to that described in previous deliverables such as WG1 WP1 D10 and WG1 WP1 D11/D12. These preceding deliverables were concerned with the operation of devices with linear and nonlinear PTO mechanisms in regular and irregular waves, respectively. Therefore, this deliverable draws together parts ofthe experimental programme and the fully nonlinear aspects of thenumerical modelling work stream.
The objective of the deliverable was to simulate the experimental device performance tests using the fully nonlinear model and to compare the results. This report provides an account of how thedifferent aspects of performance tests were modelled, including a description of the PTO force model and an analysis and numerical reconstruction of the experimental wave generation procedure.The device displacement, PTO force and the power absorbed time-histories of the fully nonlinear simulations of the performance tests are compared to the experimentally measured behaviour for both the operation of isolated devices and four devices within a square array. Analysis of repeatability tests indicated that in some cases a large degree of uncertainty existed in the results and so the mean time-histories over the set of repeatability tests were used for comparison. A measure of the agreement between the numerical and experimental results is also included. |
