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:
Keyword | Notes |
Name | - |
Orientation | - |
RNA nodes | If no node is specified, the tubular tower will have no RNA |
Substructure node | This only applies for tubular towers connected to another support section, such as a monopile, a truss tower or a floater |
Materials | - |
Circular hollow cross section | Different types of cross sections can be defined, but Circular hollow are the most common |
Nodes | - |
Slave nodes | This is typically used to create hinges |
Members | - |
Supports | In 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 |
Springs | Springs (linear or non-linear) are generally applied when part of the tubular tower is below the ground |
Non-linear springs | - |
Damping loads | - |
Transforms | Applies 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.
Keyword | Notes |
Name | - |
Orientation | - |
Tower node | If this is left empty, the monopile will not have any tubular tower |
Materials | - |
Circular hollow cross section | Different types of cross sections can be defined, but Circular hollow are the most common |
Nodes | - |
Slave nodes | This is typically used to create hinges |
Members | - |
Supports | Specifies 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. |
Springs | Springs (linear or non-linear) are generally applied when part of the monopile is below the ground |
Non-linear springs | - |
Damping loads | - |
Transforms | Applies 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)
Keyword | Notes |
Name | - |
Orientation | - |
RNA nodes | If no node is specified, the truss tower will have no RNA |
Tubular tower node | If this is left empty, the monopile will not have any tubular tower |
Materials | - |
Circular hollow cross section | Different types of cross sections can be defined, but Circular hollow are the most common |
Nodes | - |
Slave nodes | This is typically used to create hinges |
Members | - |
Supports | Specifies 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. |
Springs | Springs (linear or non-linear) are generally applied when part of the tubular tower is below the ground |
Non-linear springs | - |
Damping loads | - |
Transforms | Applies 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.
Keyword | Notes |
Name | - |
Orientation | - |
Mooring lines | If 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 node | If 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 section | Different types of cross sections can be defined, but Circular hollow are the most common |
Nodes | - |
Slave nodes | This is typically used to create hinges |
Members | - |
Supports | This is typically left empty since the floater is moored to the seabed |
Springs | This is typically left empty since the floater is moored to the seabed |
Non-linear springs | - |
Damping loads | - |
Transforms | Applies 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.
Keyword | Notes |
Materials | - |
Circular solid cross section | Different types of cross sections are available, but the circular solid is the most common for mooring lines |
Line section | - |