obsidian_backup/多体+耦合求解器/Bladed坐标系.md

7.21 Coordinate systems and outputs
A large amount of output is potentially available from some simulations. Click the Outputs button on the Calculations screen to define which of these outputs are required. The outputs are grouped into blade, tower and other outputs.
The Aerodynamic information, Performance coefficients and Power curve calculations are unaffected, as they produce a pre-defined set of outputs.

7.21.1 Blade coordinate systems and outputs
To configure blade outputs, click Blade outputs on the Calculation Outputs Specification screen.
Blade outputs include aerodynamic information (including distributed aerodynamic loadings), blade loads and motions. For each of these categories, the information may be generated at any or all of the blade stations (see 3.1). Click Select Output Stations to determine which information is required at which stations. Click Add to define additional points where interpolated loads will be output.
Having defined the blade stations required, specify for each type of output whether that information is required on the First blade, All blades, or not at all (None).
The loads can be specified independently about the following axes: Principal axes, Root Axes, Aerodynamic Axes and User Axes. Within each group, the loads are labeled Mx, My, Mxy, Mz, Fx, Fy, Fxy, Fz.
It’s important to note that the Principal Axes and Root Axes stations coincide with the underlying finite beam element model nodes. The Principal Axes coordinate vectors align with the finite beam elements. The Root Axes coordinates have the same origin rotated to align with the blade root.
The Aerodynamic and User Axes potentially have origins that do not coindicide with the underlying finite element beam model nodes. These load outputs are found by transforming the finite element loads (in the Principal Axes coordinates) to the Aerodynamic or User Axes coordinate centre. The tranformation accounts for additional Mx and My bending moments that are generated at the Aerodynamic or User Axis centre by the element axial force Fz in the Principal Axes system, due to the offset in the aerofoil plane between these two coodinate centres. This effectively estimates the load that would have occurred if the load was carried through an axis at the Aerodynamic Axis or User Axis centre. There is some approximation in this method as the Aerodynamic and User Axes loads are not the true load path. Any changes to the the blade dynamics (e.g. deflections or loads) that might result from such a change in load path are not accounted for.
# 7.21 坐标系和输出

一些模拟可能产生大量的输出数据。点击“计算”屏幕上的“输出”按钮，以定义所需的输出类型。这些输出被分为叶片、塔架和其他输出。

气动信息、性能系数和功率曲线计算不受影响，因为它们产生一组预定义的输出。

## 7.21.1 叶片坐标系和输出

要配置叶片输出，请点击“计算输出规范”屏幕上的“叶片输出”。

叶片输出包括气动信息（包括分布式气动载荷）、叶片载荷和运动。对于这些类别中的每一个，信息可以在任何或所有叶片站（见3.1）生成。点击“选择输出站”以确定在哪些站需要哪些信息。点击“添加”以定义额外输出插值载荷的点。

在定义了所需的叶片站后，为每种类型的输出指定是否需要在第一叶片、所有叶片或根本不需要（无）上输出该信息。

载荷可以独立地指定关于以下轴：主轴、根轴、气动轴和用户轴。在每个组中，载荷分别标记为Mx、My、Mxy、Mz、Fx、Fy、Fxy、Fz。

需要注意的是，主轴和根轴站与底层的有限梁单元模型节点重合。主轴坐标向量与有限梁单元对齐。根轴坐标具有相同的原点，并旋转以与叶片根对齐。

气动轴和用户轴的原点可能与底层的有限单元梁模型节点不重合。这些载荷输出是通过将有限单元载荷（在主轴坐标系中）变换到气动轴或用户轴坐标中心来获得的。这种变换考虑了在气动轴或用户轴中心由于气动面与这两个坐标中心之间的偏移产生的额外Mx和My弯矩，这些弯矩是由有限单元的轴向力Fz在主轴系中产生的。这有效地估计了如果载荷通过气动轴或用户轴中心的轴传递，会发生的载荷。由于气动轴和用户轴载荷不是真实的载荷路径，因此这种方法存在一定的近似。任何由于这种载荷路径变化可能导致的叶片动力学变化（例如，挠曲或载荷）都不会被考虑在内。
### Principal axes
Principal axes: The positive z-axis follows the local deflected neutral axis at each blade station towards the blade tip. The positive y axis is defined by the principal axis orientation. The positive x axis is orthogonal to the y and z and follows the right hand rule. For output loads, the origin of the axes is on the neutral axis at each local deflected blade station. (see diagram below)

主轴：正向z轴沿每个叶片位置向叶片末端的挠曲中性轴延伸。正向y轴由主要轴系方向定义。正向x轴垂直于y轴和z轴，并遵循右手螺旋定则。对于输出载荷，坐标原点位于每个挠曲中性轴上。（见下方的示意图）

![[Pasted image 20250610111507.png]]Blade principal axes coordinate system

Note that there is a subtle difference between the “principal axis” frame and the “blade local element frame”.
The “blade local element frame” is orientated so that the X vector in this coordinate system points directly between adjacent nodes on the blade. The other two coordinate system vector directions are determined by the “principal axis twist” angle. This is explained in more detail in DNV GL technical note UKBR-110052-T-31-A
The “principal axis” frame is used for load output in Bladed. The principal axis orientation is calculated by taking the average orientation of the two blade elements at the node where the elements join. This is illustrated below. The two adjoining local element frames are shown in green and red. The principal axes output frame is shown in blue.
Note that the element local coordinate system has its x direction along the element, unlike the “principal axes” coordinate system which has z along the element axis.
需要注意的是，“主轴系”和“叶片局部单元系”之间存在细微差别。
“叶片局部单元系”的定向方式是，该坐标系中的X向量直接指向叶片上相邻节点之间的连线。另外两个坐标系向量方向由“主轴扭转”角度决定。 详情请参见DNV GL技术备忘录UKBR-110052-T-31-A。
**Bladed中用于输出载荷的是“主轴系”**。主轴方向的计算是通过取叶片节点处两个叶片单元的平均方向来实现的。下图所示。两个相邻的局部单元系分别用绿色和红色表示。主轴输出系用蓝色表示。
需要注意的是，局部单元坐标系的x方向沿着单元方向，而“主轴系”坐标系的z方向沿着单元轴方向。

![[Pasted image 20250610113014.png]]
Relationship between blade "local element axes" and "principal axes coordinates"

### Root axes
Root axes: The orientation of the axes is fixed to the blade root and does not rotate with either twist or blade deflection. The axis set does rotate about the z axis with pitch. For output loads, the origin of the axes is on the neutral axis at each local deflected blade station.
根部坐标轴：坐标轴的方向固定于叶片根部，不会随扭角或叶片挠曲而旋转。坐标轴系会绕z轴旋转，以适应变桨角度。对于输出载荷，坐标轴原点位于每个局部挠曲叶片位置的受力中性轴上。

![[Pasted image 20250610143738.png]]
Blade root axes coordinate system

### Aerodynamic axes
**Aerodynamic axes**: The x axis is perpendicular to the local aerodynamic chord line and the positive y axis is aligned along the local aerodynamic chord line from leading edge to trailing edge. The z-axis is parallel to the local deflected neutral axis at each blade station and increases towards the blade tip. For output loads, the origin of the axes is on the chord line at 25% chord from the leading edge at each local deflected blade station.
**气动坐标系**: x轴垂直于当地气动弦线，正向y轴沿当地气动弦线从前缘到后缘排列。z轴平行于每个叶片位置的当地偏转中性轴，并向叶片末端增加。对于输出载荷，坐标系原点位于每个当地偏转叶片位置的弦线上，距离前缘弦线25%的位置。
![[Pasted image 20250610144407.png]]
Blade Aerodynamic axes coordinate system

### User axes
**User axes**: The origin of the axes is specified as percentages of chord, parallel and
perpendicular to the chord at each blade station. The user can specify whether the z-axis is
parallel to the root axis or the local neutral axis, and independently whether the y-axis is aligned
to the principal axis orientation, the aerodynamic twist or the root axis.
**用户坐标系**: 坐标原点以弦长的百分比为准，并在每个叶片位置平行于弦长方向和垂直于弦长方向定义。用户可以指定 z 轴是否平行于根轴或局部中性轴，并且可以独立地指定 y 轴是否与主轴方向、气动扭角或根轴对齐。


**The coordinate system for the blade deflections is as follows:**
z-axis Radially along the blade root Z axis
x-axis Perpendicular to z, and pointing towards the tower for an upwind turbine, or away from the tower for a downwind turbine.
y-axis Perpendicular to blade axis and shaft axis, to give a right-handed co-ordinate system independent of direction of rotation and rotor location upwind or downwind of the tower.

**叶片挠曲的坐标系定义如下：**
z轴 沿叶片根部径向分布
x轴 与z轴垂直，对于迎风式风轮，指向塔架；对于背风式风轮，则背离塔架。
y轴 与叶片轴线和轴线垂直，以构成一个右手坐标系，该坐标系与旋转方向和风轮在塔架迎风或背风位置无关。


3.2 Blade geometry
The blade geometry is defined at each blade station (see 3.1) clicking on the data item to be defined or changed. The following data is required at each station:
Distance: This can be entered as a distance along the blade or as a distance along the blade root Z-axis. Select the appropriate option at the base of the screen.
• Distance along blade: the distance from the blade root to the current blade station, along the blade neutral axis, which does not have to be a straight line. It must be zero for the first station. If distance is entered along the blade root Z-axis, this value is calculated based on the distance along the blade root Z-axis and the neutral axis.
• Distance along blade root Z-axis: the distance of the blade station along the nominal pitch axis (with no pre-sweep or pre-cone). If distance is entered along the blade, this value is calculated based on the distance along the blade and the neutral axis.
• Chord: the distance from the leading edge to the trailing edge, i.e. along the chord line.
• Aerodynamic Twist: the local angle of the chord line. More positive values of twist and set angle push the leading edge further upwind. (See diagram below)
• Thickness: the thickness of the blade as a percentage of the chord at that station.
• Neutral axis (x): the distance from the blade root Z-axis to the neutral axis in the x direction. This would be non-zero if for example the blade was pre-bent. (See diagram below)
• Neutral axis (y): the distance from the blade root Z-axis to the neutral axis in the y direction. (See
diagram below)
• Neutral axis, local (x’): the perpendicular distance from the chord line to the neutral axis in local
coordinates, as a percentage of the chord. (See diagram below)
• Neutral axis, local (y’): the distance along the chord line from the leading edge to the neutral axis
in local coordinates, as a percentage of the chord. (See diagram below)
• Foil section: an index number defining the aerofoil section (see 3.8) at that station
• Moving/Fixed: differentiates between a fixed part of the blade and a part which is movable to
achieve aerodynamic regulation or braking, either by bodily changing the pitch of that part of the
blade, or by deploying an aileron, flap or other aerodynamic control (see 4.1) surfaces.

3.2 叶片几何

叶片几何在每个叶片位置（见3.1）被定义，通过点击要定义或修改的数据项来操作。每个位置需要以下数据：
• 距离：可以输入为沿叶片方向的距离，也可以输入为沿叶片根部Z轴方向的距离。在屏幕底部选择合适的选项。
• 沿叶片方向的距离：从叶片根部到当前叶片位置沿叶片中性轴的距离，该中性轴不必为直线。对于第一个位置，该值为零。如果输入沿叶片根部Z轴方向的距离，则该值基于沿叶片根部Z轴方向的距离和中性轴计算得出。
• 沿叶片根部Z轴方向的距离：当前叶片位置沿标称迎角轴（无预先偏扫或预先锥角）的距离。如果输入沿叶片方向的距离，则该值基于沿叶片方向的距离和中性轴计算得出。
• 弦长：从前缘到后缘的距离，即沿弦线方向的距离。
• 空气动力学扭角：弦线在该位置的局部角度。更大的扭角和偏转角会将前缘推向更上风的位置。（见下方的图表）
• 厚度：该位置的叶片厚度，以弦长的百分比表示。
• 中性轴 (x)：从叶片根部Z轴到中性轴在x方向上的距离。如果叶片预先弯曲，则该值将不为零。（见下方的图表）
• 中性轴 (y)：从叶片根部Z轴到中性轴在y方向上的距离。（见下方的图表）
• 局部中性轴 (x’)：从弦线到中性轴在局部坐标系中的垂直距离，以弦长的百分比表示。（见下方的图表）
• 局部中性轴 (y’)：从前缘到中性轴沿弦线的距离，以弦长的百分比表示。（见下方的图表）
• 翼型剖面：定义该位置的翼型剖面（见3.8）的索引号。
• 固定/可动：区分叶片的固定部分和可移动部分，用于实现空气动力学调节或制动，可以通过改变该部分叶片的迎角，或展开副翼、叶片（flap）或其他空气动力学控制面（见4.1）来实现。


## 7.21.2 Hub coordinate system
To configure hub outputs, click Other Outputs on the Calculation Outputs Specification screen.
The co-ordinate system for the hub load and deflection outputs from the calculations is based on the ‘GL’ convention, with some modifications as specified below.


Hub loads in fixed frame of reference:
XN Along shaft axis, and pointing towards the tower for an upwind turbine, or away from the tower for a downwind turbine (the picture shows an upwind turbine).
ZN Perpendicular to XN, such that ZN would be vertically upwards if the tilt angle were zero.
YN Horizontal, to give a right-handed co-ordinate system independent of direction of rotation and rotor location upwind or downwind of the tower.

Co-ordinate system for stationary hub loads
要配置轮毂输出，请在“计算输出规范”屏幕上点击“其他输出”。

来自计算的轮毂载荷和挠度输出的坐标系基于“GL”惯例，并根据以下说明进行了一些修改。

![[Pasted image 20250610154850.png]]

轮毂载荷（固定参考系）：
XN 沿轴向，对于迎风式风轮，指向塔架；对于背风式风轮，则背离塔架（图片显示的是迎风式风轮）。
ZN 与 XN 垂直，如果倾斜角度为零，则 ZN 将垂直向上。
YN 水平方向，以提供一个与旋转方向和风轮位于迎风或背风位置无关的右手坐标系。

静止轮毂载荷坐标系

![[Pasted image 20250610155051.png]]

Hub loads in rotating frame of reference:
XN Along shaft axis, and pointing towards the tower for an upwind turbine, or away from the tower for a downwind turbine (the picture shows an upwind turbine).
ZN Perpendicular to XN, such that ZN would be aligned with blade 1 axis if the cone angle were zero.
YN Perpendicular to XN and ZN, to give a right-handed co-ordinate system independent of direction of rotation and rotor location upwind or downwind of the tower.
Origin At hub centre (intersection of blade and shaft axes).
Figure 7-9: Co-ordinate system for rotating hub loads
旋转坐标系下的叶片中心载荷：

轮毂的旋转坐标系随叶片旋转，ZR跟随叶片1
XN 沿轴向，对于迎风式风轮指向塔架，对于顺风式风轮则背向塔架（图示为迎风式风轮）。
ZN 与 XN 垂直，如果锥角为零，则 ZN 将与叶片 1 轴对齐。
YN 与 XN 和 ZN 垂直，构成一个右手坐标系，该坐标系与旋转方向和风轮位于迎风侧或顺风侧无关。
原点 位于叶片中心（叶片和轴的交点）。
图 7-9：旋转叶片中心载荷坐标系

## 7.21.3 Anti-clockwise and downstream rotor coordinate systems

The rotor and blade output coordinate systems for all permutations of clockwise, anti-clockwise, downstream and upstream rotors are shown in the following four figures.
Note that for simplicity these diagrams do not include blade mounting cone, blade mounting sweep. The blade pitch and set angle are shown at zero in these diagrams.
风轮和叶片的输出坐标系，针对顺时针、逆时针、向下游和向上游风轮的所有排列方式，见下四幅图。
请注意，为了简化起见，这些图未包含叶片安装锥度和叶片展向。图中显示的是零变桨角度和零扭角。
![[Pasted image 20250610155315.png]]Blade and rotor coordinate systems for a clockwise upstream rotor

![[Pasted image 20250610155646.png]]Blade and rotor coordinate systems for an anticlockwise upstream rotor

![[Pasted image 20250610155658.png]]Blade and rotor coordinate systems for a clockwise downstream rotor

![[Pasted image 20250610155729.png]]
Blade and rotor coordinate systems for an anticlockwise downstream rotor

## 7.21.4 Tower outputs
Click Tower outputs on the Calculation Outputs Specification screen.
Tower loads may be generated at any or all of the tower stations (see 4.5). Click Select Output Stations to determine at which stations the loads are to be output. For the monopile tower model, click Add to define additional points where interpolated loads will be output.
Having defined the tower stations required, specify for each individual output whether that information is required. For the loads, this can be specified independently for each of the forces and moments.
There is also an option to Refine deflections. With this option disabled, the tower deflection outputs are modal deflections. Modal deflections give a good estimate of overall tower motion, but may not be very precise in predicting the small deflections at foundation stations. This can lead to a poor estimate of the foundation reaction loads given the applied loads on the rest of the turbine.
With the Refine deflections feature enabled, the tower deflections are re-calculated at each output time step using the underlying finite element model with the external loads applied. The refined deflections give a more accurate estimate of the deflections at the foundation nodes, hence the foundation reaction forces are more accurate, especially for non-linear foundations. With Refine deflections selected, Bladed will iterate at each output time step to find the foundation applied loads based on the refined deflections. This will ensure that the applied loads, tower deflections and foundation reactions correspond correctly.
Note that the modal deflections are used to estimate the foundation loads when solving the structural system at each integrator time step. To use the refined deflections at every time step would require iteration on each time step, causing a significant increase in simulation time. The assumption with this modelling choice is that error in foundation load estimate due to using modal deflections doesn’t affect the overall turbine dynamics significantly. It is therefore reasonable to only calculate the foundation reaction loads based on refined deflection on each output time step.

计算输出结果显示在“计算输出规范”屏幕上。
塔架载荷可能在塔架的任何或所有站（参见 4.5）产生。点击“选择输出站”以确定载荷输出的站。对于单桩塔架模型，点击“添加”以定义额外的输出插值载荷的点。
在定义了所需的塔架站后，为每个单独的输出指定是否需要该信息。对于载荷，可以为每个力矩分别指定。
还有一个“细化挠度”的选项。当此选项禁用时，塔架挠度输出为模态挠度。模态挠度可以很好地估计塔架的整体运动，但可能无法准确预测地基站的小挠度。这可能导致根据其余部分叶片的载荷，地基反作用力估计不准确。
启用“细化挠度”功能后，塔架挠度将在每个输出时间步重新计算，使用外部载荷作用下的底层有限元模型。细化后的挠度可以更准确地估计地基节点的挠度，因此地基反作用力更准确，尤其对于非线性地基。当选择“细化挠度”后，Bladed 将在每个输出时间步迭代以找到基于细化挠度作用于地基的载荷。这将确保作用的载荷、塔架挠度和地基反作用力正确对应。
请注意，模态挠度用于在每个积分时间步求解结构系统时估计地基载荷。在每个时间步都使用细化挠度将需要对每个时间步进行迭代，从而导致模拟时间显著增加。此建模选择的假设是，由于使用模态挠度导致的地基载荷估计误差不会对整体风轮动力学产生显著影响。因此，仅在每个输出时间步基于细化挠度计算地基反作用力是合理的。

## 7.21.5 Tower co-ordinate systems
The co-ordinate system for tower outputs is based on the GL convention, as described below.

![[Pasted image 20250610160454.png]]

XT Pointing South.
ZT Pointing along deflected tower centre line.
YT Pointing East.
Origin At each tower station.
Note that for steady-state calculations the wind is deemed to come from the North.
Figure 7-14: Co-ordinate system for tower loads (monopile only) and deflections

Note that the coordinate system system for tower loads moves with tower modal deflections, so that the coordinate system remains aligned with the deflected member axis.
需要注意的是，塔架载荷的坐标系会随着塔架模态挠度而移动，以保持坐标系与挠曲构件轴对齐。

Loads and deflections for multi-member towers
The loads are output with reference to the local member coordinate system for each member. The member x-axis is always aligned along the member. The member z axis is perpendicular to the member x-axis and aligned according to the direction cosines for the member z-axis as specified in the tower screen. These are the direction cosines of the z-axis relative to the global GL coordinate system. For example, a vertical member with z-axis direction cosine of 0.0 in the x-direction, 1.0 in the y-direction and 0.0 in the z-direction would be a member where the local x-axis corresponds to the GL z-axis, the local y-axis corresponds to the GL x-axis and the local z-axis corresponds to the GL y-axis.
The deflections are output in the GL coordinate system.
Bladed multi-member output convention: local x-y plane:
多节塔架的载荷和挠度

载荷以每个节体的局部节体坐标系输出。节体的x轴始终与节体对齐。节体的z轴垂直于节体的x轴，并根据塔架屏幕中指定的节体z轴的方向余弦进行对齐。这些是z轴相对于全局GL坐标系的方向余弦。例如，一个z轴方向余弦在x方向为0.0，在y方向为1.0，在z方向为0.0的垂直节体，其局部x轴对应GL z轴，局部y轴对应GL x轴，局部z轴对应GL y轴。

挠度以GL坐标系输出。


## 7.21.6 Pitch system direction convention
![[Pasted image 20250610161112.png]]

Figure 7-16: Pitch system sign convention
The same sign convention applies to the applied pitching moment, pitch bearing friction and pitch actuator torque. A positive applied pitching moment means that the blade aerodynamic, gravitational and other applied forces act in such a way as to drive the pitch in the positive (feathering) direction.
Pitch system loads and deflections:
For pitch angles, rates and accelerations, the positive direction is the direction in which the leading edge moves upwind, i.e. towards the feathered position:
相同的符号惯例适用于施加的偏转力矩、偏转轴承摩擦力和偏转执行器扭矩。正向施加偏转力矩意味着叶片的气动力、重力和其他施加力作用于使偏转角度朝正（feathering）方向运动。

偏转系统载荷和挠曲：

对于变桨角度、变桨速率和变桨加速度，正向是指前缘向迎风方向移动，即向feathering位置的方向。

## 7.21.7 Yaw bearing output
The yaw bearing is located at the “nacelle node” as specified in the support structure screen. For monopile towers, the yaw bearing is assumed to be located at the top tower station.
The co-ordinate system for yaw bearing loads is the same as for the top tower station except that it rotates with the nacelle yaw angle.
Yaw bearing output is defined opposite to the GL z-axis, with clockwise from North being positive.
支撑结构屏幕中，偏航轴承位于“吊舱节点”处。对于单桩塔架，假设偏航轴承位于塔顶位置。
偏航轴承载荷的坐标系与塔顶位置的坐标系相同，但会随着吊舱偏航角度旋转。
偏航轴承输出定义为与GL z轴相反，以北为正，顺时针方向为正。
## 7.21.8 Variables that follow “rotor direction is positive” convention
There are a number of other variables for which the positive direction is the ‘normal running’ direction. This applies to controller and drive train variables such as rotor and generator speeds, torques and azimuthal positions, drive train and generator torques etc.

还有一些其他变量，其正方向为“正常运行”方向。这适用于控制器和传动系变量，例如风轮和发电机转速、扭矩和方位角位置、传动系和发电机扭矩等。

## 7.21.9 Other general outputs
• Summary information: includes principal operational and environmental indicators.
• Software performance: useful for diagnosing slow simulations, and finding a suitable step length for Real Time Test simulations.
• Specific node outputs: This is an advanced feature, intended for users with some knowledge of the Multibody Dynamics approach used within Bladed. See the description below.
Clicking the Specific node outputs… button will open the Node Outputs screen, which allows you to add, delete or edit entries in the node outputs list. This is a list of structural nodes at which you want to see kinematic (position, velocity, acceleration) or loads outputs.
To see a tree diagram of node identifiers and the components they are connected to, run Bladed once without altering the project details (a 1-second simulation is enough), and then open the verification (.$VE) file in a text editor. Any node and component identifiers you enter must be exactly as they appear in this tree, and the component must be connected directly to the node. For each node, choose the type – Loads or kinematics – and the coordinate system in which you want the outputs to be expressed. Specify a name for the output group; this is the name that will appear in the list of outputs in the dataviewer. You can also choose to have the outputs calculated at a position (Offset) other than that of the node itself. This option should be used with care, as it must represent a position in space that is physically on the turbine structure, otherwise the outputs will be meaningless.
• 概要信息：包含主要运行和环境指标。
• 软件性能：用于诊断模拟速度慢，并为实时测试模拟找到合适的步长。
• 特定节点输出：这是一个高级功能，面向对Bladed内部使用的多体动力学方法有所了解的用户。请参阅下方描述。
点击“特定节点输出…”按钮将打开“节点输出”屏幕，您可以在此屏幕上添加、删除或编辑节点输出列表中的条目。此列表是您希望查看运动学（位置、速度、加速度）或载荷输出的结构节点列表。
要查看节点标识符及其连接组件的树状图，请在不更改项目详细信息的情况下运行Bladed一次（1秒的模拟就足够了），然后在一个文本编辑器中打开验证文件（.$VE）。您输入的任何节点和组件标识符必须与此树中的显示方式完全一致，并且组件必须直接连接到节点。对于每个节点，选择类型——载荷或运动学——以及您希望以其表达输出的坐标系。为输出组指定一个名称；此名称将出现在数据查看器中的输出列表。您还可以选择在节点自身位置（偏移量 Offset）以外的位置计算输出。应谨慎使用此选项，因为它必须表示一个位于风机结构上的空间位置，否则输出将毫无意义。


## 7.21.10 Environmental information
These outputs describe the wind speed and direction, as well as the sea surface elevation and seismic motions, if present. All speeds are relative to the hub or rotor motion, so any motion of the nacelle is reflected in these outputs.
Hub wind speed magnitude: This is the overall relative flow speed magnitude experienced by the hub.
Cup anemometer wind speed: This is the horizontal component of the hub wind speed magnitude.
Hub longitudinal wind speed: The component of the horizontal wind speed aligned with the hub longitudinal direction (includes rotation due to yaw angle).
Hub lateral wind speed: The component of the horizontal wind speed aligned with the hub lateral direction (includes rotation due to yaw angle).
Hub vertical wind speed: The component of the flow speed magnitude in the vertical direction.
Wind direction at hub: Direction, as an angle to North (clockwise looking down).
Wind upflow at hub: Upflow, as an angle to the vector of flow direction in the horizontal plane. Positive angle is upwards.
Rotor average longitudinal wind speed: Component of the overall flow speed along the hub X axis, averaged over the rotor plane. The rotor is effectively treated as a non-rotating disc.
Rotor average longitudinal wind direction: Direction, as an angle to North (clockwise looking down), averaged over the rotor plane as above.
Sea surface elevation: Instantaneous sea surface Z in global coordinates, at global X=0, Y=0.
Ground positions, velocities, accelerations: Seismic motion of the ground at the turbine base, in global coordinates.