Operation and Maintenance (O&M) costs are estimated to account for 14%–30% of total Offshore Wind Farm (OWF) project lifecycle expenditure according a range studies. In this respect, identifying factors affecting operational availability vital wind farm operators achieve the most profitable decisions. Many OWFs built in stages important may not be consistent different phases. To address issue, three OWF case studies defined represent two phases complete project. An initial qualitative...

Most fatigue loaded structural components are subjected to variable amplitude loads which must be processed into a form that is compatible with design life calculations. Rainflow counting allows individual stress cycles identified where they closed stress–strain hysteresis loop within random signal, but inevitably leaves residue of open data points post-processed. Comparison made between conventional methods processing the points, may non-conservative, and more versatile method, presented by...

Multi-functional platform is a promising way to enhance the economic power production from multiple renewable energy sources. This paper investigates numerically and experimentally hydrodynamic performance of an oscillating water column (OWC) wave converter (WEC), integrated into monopile-mounted offshore wind turbine (OWT). Based on linear potential flow theory, 3D time-domain numerical model was developed, based higher-order boundary element method, investigate coupled response...

The hydrodynamic performance of a stationary cylindrical dual-chamber Oscillating Water Column (OWC) wave energy device was experimentally studied to assess conversion efficiency in comparison with single-chamber OWC. contribution the present work is guide design and optimization OWC for efficiently capturing offshore energy. effects various parameters including steepness, opening ratio, inner- outer-chamber drafts on proposed were considered. It found that increases by one. A coupled...

This article explores an automated approach for the efficient placement of substations and design inter-array electrical collection network offshore wind farm through minimization cost. To accomplish this, problem is represented as a number sub-problems that are solved in series using combination heuristic algorithms. The overall first by clustering turbines to generate valid substation positions. From navigational mesh pathfinding algorithm based on Delaunay triangulation applied identify...

This article explores the application of a wind farm layout evaluation function and optimization framework to Middelgrunden in Denmark. has been built considering interests developers order aid planning future offshore farms using UK Round 3 as point reference calibrate model. The present work applies developed tool estimate cost, energy production, levelized cost for existing as-built at farm; comparing these against production reported by operator. From here, new layouts have then designed...

Analytical solutions for wave interaction with a vertical porous barrier are presented. The analytical derived using two different methods taking the depth-average of pressure drop across barrier. Both assume that evanescent modes in field can be neglected. results from models compared to an iterative boundary element method (BEM) model. BEM model shows neglecting is reasonable assumption long waves, but short waves velocity through wall up 25% progressive at free surface. However, effect...

Ocean waves are widely estimated using physics-based computational models, which predict how energy is transferred from the wind, dissipated, and spatially across ocean. Machine learning methods offer an opportunity to these data with significantly reduced input power. This paper describes a novel surrogate model developed random forest method, replicates spatial nearshore wave by Simulating WAves Nearshore (SWAN) numerical model. By incorporating in-situ buoy observations, outputs were...

Floating offshore wind turbines are characterised by complex coupled dynamics between the floating structure and turbine. These subjected to a combination of aerodynamic, hydrodynamic servo-dynamic loads which must be quantified when considering requirements mooring anchoring system. If suitably engineered, shared anchors enable reduced hardware installation costs for turbines. This paper presents results dynamic simulations, evaluating single anchor different configurations IEA 15 MW...

A boundary element method (BEM) model is presented for wave forces on structures composed of solid and porous surfaces, where the surface can be subject to either a linear or quadratic pressure–velocity relation. In case relation, solutions radiation diffraction problems cannot superimposed obtain solution body motions in waves. Instead, proposed which solves motion response simultaneously. Solutions are then obtained as special cases. Hydrodynamic identities expressions mean drift force...

We consider wave forces on fixed porous cylinders with and without a solid inner cylinder wave-induced motions of floating outer cylinder. Comparisons between experimental measurements numerical predictions from an iterative boundary element method (BEM) model are presented. The BEM assumes that pressure drop across surface is proportional to the square velocity through surface. It shown able accurately predict nonlinear variation amplitude or motion amplitude. demonstrated adding vertical...

This paper investigates the dynamic response of a fully nonlinear model DeepCWind floating offshore wind turbine (FOWT) after one its three-catenary mooring systems is broken. The drift area platform, pitch motion turbine, and tension on two ends line are main foci; in addition, single mathematical formula provided this study to predict maximum surge direction. After platform reaches new equilibrium position maintained by remaining lines, tower exceeds 20 degrees. change closely related...