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# Offshore vindenergi (Offshore Wind Energy )

Language

English

Course format On-site
Date 2020-08-31 - 2020-12-16

#### General course objectives

To be able to calculate hydrodynamic and aerodynamic loads specific for offshore wind turbines.

#### Content

• Design codes for bottom fixed offshore wind turbines. Design basis for wind and wave climate. Extreme value prediction by fitted distributions.
• Substructure types for offshore wind turbines. Design of a substructure.
• Hydrodynamic loads from linear irregular waves. Wave kinematics and the Morison equation. Wheeler stretching and the MacCamy Fuchs diffraction theory. Simplified aerodynamic load model.
• The 1P and 3P dynamic criteria and basic technique for fatigue calculation.
• Wake aerodynamics and vortex structures behind a wind turbine rotor. 1D momentum theory for wakes. Wake interaction in wind farms. Methods for computation of wakes in wind farms.
• Introduction to planning and environmental decisions for offshore wind farms. Introduction to operation and maintenance management for offshore wind farms.
• Basic concepts for floating wind turbines and calculation of mooring forces. Linearised equations of motion for floating wind turbines. Dynamic stability and control of floating wind turbines.

## Prerequisites

##### Recommended prerequisites

Matlab skills equivalent to course 02631/02633. This level of Matlab skills is essential to carry out the course reports. 41106. Fluid Mechanics equivalent to course 41312 or 41101. Numerical Analysis equivalent to course 02601. 46300 - can with some effort be taken concurrently.

## Learning outcomes

A student who has met the objectives of the course will be able to:

• Describe the typical foundation types for bottom-fixed offshore wind turbines and summarize the content of the IEC 61400-3 design norm
• Apply the elements of a design basis and use statistical data to determine e.g. a 50-year sea state
• Calculate a force time series from linear irregular waves and determine which forces that dominate
• Explain the basic dynamics of bottom fixed offshore wind turbines, the method for fatigue calculations and perform a simple substructure design
• Apply 1D momentum theory for analysis of wind turbine wakes
• Implement closed-form wake models in Matlab
• Analyse the production in rows of wind turbines with application of closed-form wake models and determine the optimal spacing between the wind turbines
• Describe the basic process in planning an offshore wind farm and the interaction between the involved parties
• Understand and suggest simple strategies for operation and maintenance
• Derive the equations of motion for typical floating wind turbine configurations
• Implement time domain models for the dynamics of floating wind turbines subject to wind and wave forcing
• Analyse the dynamic stability of floating wind turbines and propose modifications of the control system to improve stability

## ISCED Categories

Offshore and renewable energy