Support section examples

This section gives examples of how typical support sections are defined. Many different concepts use non-conventional configurations, so this section is only meant as an indication of how to generate the most common types of wind turbines. The format to follow for each keyword is given in the Keywords section.

1 Tubular tower

In general, the tubular tower is the support section that holds the RNA at its highest node. To model onshore turbines, it is common to have a tubular tower directly mounted onto the ground. For offshore turbines, the tubular tower is mounted on a monopile and for floating turbines the tower is mounted on the floater itself. The input file that defines a tubular tower is generaly defined with the following keyword sections:

KeywordNotes
Name-
Orientation-
RNA nodesIf no node is specified, the tubular tower will have no RNA
Substructure nodeThis only applies for tubular towers connected to another support section, such as a monopile, a truss tower or a floater
Materials-
Circular hollow cross sectionDifferent types of cross sections can be defined, but Circular hollow are the most common
Nodes-
Slave nodesThis is typically used to create hinges
Members-
SupportsIn general, this is only used for standalone tubular towers. If supports are specified for a tower on another support section, the node will have some or all of its degrees of freedom constrained
SpringsSprings (linear or non-linear) are generally applied when part of the tubular tower is below the ground
Non-linear springs-
Damping loads-
TransformsApplies a rotation, translation or scaling when importing the suppoer section into Ashes

2 Monopile

The monopile is the most common type of foundation for offshore wind turbines. It generally extends below the seabed and has the tubular tower on its highest node.

KeywordNotes
Name-
Orientation-
Tower nodeIf this is left empty, the monopile will not have any tubular tower
Materials-
Circular hollow cross sectionDifferent types of cross sections can be defined, but Circular hollow are the most common
Nodes-
Slave nodesThis is typically used to create hinges
Members-
SupportsSpecifies how the monopile is connected to the ground. It is common to have it fixed at the seabed, or to have it pinned below the seabed together with springs.
SpringsSprings (linear or non-linear) are generally applied when part of the monopile is below the ground
Non-linear springs-
Damping loads-
TransformsApplies a rotation, translation or scaling when importing the suppoer section into Ashes

3 Truss tower

Another type of support section is the truss tower. This can be used as a foundation offshore (i.e. with a tubular tower on top) or as a standalone support section (i.e. with the RNA directly on top)

KeywordNotes
Name-
Orientation-
RNA nodesIf no node is specified, the truss tower will have no RNA
Tubular tower nodeIf this is left empty, the monopile will not have any tubular tower
Materials-
Circular hollow cross sectionDifferent types of cross sections can be defined, but Circular hollow are the most common
Nodes-
Slave nodesThis is typically used to create hinges
Members-
SupportsSpecifies how the tubular tower is connected to the ground. It is common to have it fixed at the seabed, pt to have it pinned below the seabed together with springs.
SpringsSprings (linear or non-linear) are generally applied when part of the tubular tower is below the ground
Non-linear springs-
Damping loads-
TransformsApplies a rotation, translation or scaling when importing the suppoer section into Ashes

4 Floater

The floater is generally moored to the seabed via mooeing lines. It can have one or many tubular towers that will have the RNA on top.

KeywordNotes
Name-
Orientation-
Mooring linesIf left empty, the floater will have no mooring lines. This can be relevant when the floater needs to be tested with linear springs instead of mooring.
Tubular tower nodeIf this is left empty, the floater will not have any tubular tower. For multi-rotor floaters it is common to have more than one tubular tower
Materials-
Circular hollow cross sectionDifferent types of cross sections can be defined, but Circular hollow are the most common
Nodes-
Slave nodesThis is typically used to create hinges
Members-
SupportsThis is typically left empty since the floater is moored to the seabed
SpringsThis is typically left empty since the floater is moored to the seabed
Non-linear springs-
Damping loads-
TransformsApplies a rotation, translation or scaling when importing the suppoer section into Ashes

5 Mooring line 

The mooring lines can be created from file, for example to add point masses.

KeywordNotes
Materials-
Circular solid cross sectionDifferent types of cross sections are available, but the circular solid is the most common for mooring lines
Line section-