### 10.3.4. Camberline/Thickness Definition Sub-feature

The Camberline/Thickness Definition (CamThkDef) sub-feature, found under the Blade (or Splitter) feature, defines a blade profile on a particular layer (of the FlowPath feature) according to:

- Angle data that defines the shape of the camberline, and

- Thickness data that defines the thickness of the blade along the camberline.

The Angle and Thickness views can be used to view/edit the angle data and thickness data, respectively. For details, see Angle and Thickness Views. As a side note, the blade lean angle is plotted in the blade lean graph. For details, see Blade Lean Graph.

The CamThkDef sub-feature properties are as follows:

Details of [Sub-feature Name]
Camberline/Thickness | [CamThkDef Sub-Feature Name] is derived from [parent Blade name]_Layer[Layer number]
Details of Camberline
Angle Definition | [Interpolated | User Specified] For the hub layer, this property is always set to User Specified. For other layers, the value of this property may or may not be constrained, depending on the Surface Construction option of the blade feature.
Angle Definition Type | [Theta | Beta | Theta with LE/TE Beta]
(For Beta definition only) Theta Reference | [Leading Edge | Trailing Edge]
(For Beta definition only) Theta at Reference | [Value]
(For Theta with LE/TE Beta definition only) Beta at LE | The Beta angle at the leading edge.
(For Theta with LE/TE Beta definition only) Beta at TE | The Beta angle at the trailing edge.
Angle Data Location | [Camberline | Side 1 | Side 2]
X-Axis Definition Type | [% M’ | M’ | % M | M] (Controls the type of data used for Angle Point input parameters.)
Details of Thickness
Thickness Definition | [Interpolated | User Specified] For the hub layer, this property is always set to User Specified. For other layers, the value of this property may or may not be constrained, depending on the Surface Construction option of the blade feature.
Thickness Definition Type | [Normal to Camberline on Layer surface]
X-Axis Definition Type | [% M’ | M’ | % M | M] (Controls the type of data used for Thickness Point input parameters.)
Details of Angle Point 1
X of Angle Point 1 | [Value]
Y of Angle Point 1 | [Value]
Details of Thickness Point 1
X of Thickness Point 1 | [Value]
Y of Thickness Point 1 | [Value]

CamThkDef sub-features are named according to the associated Blade name and Layer number.

When a CamThkDef sub-feature is selected in the feature tree, its angle data is displayed on the angle graph and its thickness data is displayed on the thickness graph. The angle and thickness distributions are plotted from leading edge to trailing edge.

If the Angle Definition Type is set to Theta, then the specified angle curve is used as the theta definition for the camberline.

If the Angle Definition Type is set to Beta, then the specified angle curve is used as the Beta definition for the camberline. In this case, the theta definition is derived by integrating the Beta curve using the specified Theta Reference value. The Theta Reference value can be specified at either the leading edge or the trailing edge of the blade.

If the Angle Definition Type is set to Theta with LE/TE Beta, then you can control the theta distribution as well as specify the leading and trailing edge Beta values. This type is not offered until you have generated the camberline with:

- Angle Definition Type set to Theta, and

- A Theta curve that consists of a Bezier curve having at least four control points.

When the Angle Definition Type is set to Theta with LE/TE Beta, the Beta at LE and Beta at TE values in the details view show/control the leading and trailing edge blade metal angles. These same angle values can be seen in the Angle view as the angle values of the first and last points on the Beta curve. You can also control these angle values in the Angle view by moving the second and second-last control points on the Beta curve. Note that you can parameterize the Beta at LE and Beta at TE values in the details view, which will restrict the motion of the control points in the Angle view. You can also set the second and second-last control points to be used as input parameters, causing new properties (for example, X of Angle Point 1, under the Details of Angle Point 1 property group) to be added in the details view; if you parameterize those properties, the motion of the control points in the Angle view is constrained.

When the Angle Definition Type is set to Theta with LE/TE Beta, control points can be inserted or deleted for the Bezier curve with the exception that the first, second, second-last, and last control points cannot be removed. In this mode, the curve type cannot be changed.

For parameterization purposes, the Angle and Thickness points have an X-Axis Scale property that defines what scale the data uses: % M', M’, % M, or M. This property cannot be changed when any of the graph values are parameterized.

The following topics are discussed:

- Interpolated and Non-interpolated Angle/Thickness Data
- Importing and Exporting Angle Definition Data
- Importing and Exporting Thickness Definition Data
- Converting Curves to Bezier or Spline
- Converting Angle Definition Data

#### 10.3.4.1. Interpolated and Non-interpolated Angle/Thickness Data

If the Angle Definition property of the CamThkDef feature is set to ‘Interpolated’, then the angle definition is interpolated from the blade/splitter and cannot be edited. In addition, any custom changes you may have made to this data will be discarded.

If the Thickness Definition property of the CamThkDef feature is set to ‘Interpolated’, then the thickness definition is interpolated from the blade/splitter and cannot be edited. In addition, any custom changes you may have made to this data will be discarded.

Setting both the Angle Definition and Thickness Definition to ‘Interpolated’ can be useful when the leading and/or trailing edges are curved on a blade/splitter with insufficient CamThkDef features to represent the curvature.

If you switch the Angle Definition property from ‘Interpolated’ to ‘User Specified', the angle definition will be initialized by interpolation from the blade definition, and will then become editable.

If you switch the Thickness Definition property from ‘Interpolated’ to ‘User Specified', the thickness definition will be initialized by interpolation from the blade definition, and will then become editable.

#### 10.3.4.2. Importing and Exporting Angle Definition Data

There is an import/export points mechanism for the Angle Definition to support the manipulation of the Angle Definition points outside of BladeEditor, and to provide a means to read data from a file produced externally. In the Angle view, the context menu operation 'Read Points' lets you replace the active curve data points from the data in a text file called a .ha file. The context menu operation Save Points lets you save the active data points to a .ha text file. These options are available only if the Angle Definition property in the details view for the camberline is set to `User Specified`.

The first line in the .ha file specifies the number of points. Subsequent lines in the file, one for each data point, contain the point coordinate values 'h, a', where 'h' is the horizontal or X axis value and 'a' is the angle value. The point coordinates correspond to the defining points for the angle definition curve, which may be either Theta or Beta, in radians, versus m-prime, % m-prime, m or % m.

When reading the .ha file, the data point coordinates will be interpreted based on the Angle Definition Type and the selected X axis type. If the Angle Definition Type is set to Theta, then the angle values will be interpreted as Theta values. Otherwise, the angle values will be interpreted as Beta values. If the X axis is set to m-prime or % m-prime, then the 'h' coordinates for the data points will be treated as % m-prime values, and the values will be normalized based on the first and last data points so that the values start at zero and end at 100%. If the X axis is set to m or % m, then the 'h' coordinates for the data points will be converted to m values by normalizing based on the first and last data points and then multiplying by the maximum m on the layer. These values will then be converted to % m-prime. The existing angle curve data for all segments will be replaced by a single curve segment with the data from the .ha file, and the curve type will be set to 'cubic spline'.

When you choose 'Save Points', the defining points for all curve segments will be written sequentially to the file starting with the leading edge point and ending at the trailing edge point. The 'h' coordinates will be written in the value corresponding to the selected X axis type. If the Angle Definition Type is set to Theta, then the Theta values will be written as the angle values. Otherwise, the Beta values will be written as the angle values.

#### 10.3.4.3. Importing and Exporting Thickness Definition Data

There is an import/export points mechanism for the Thickness Definition to support the manipulation of the Thickness Definition points outside of BladeEditor, and to provide a means to read data from a file produced externally. In the Angle view, the context menu operation 'Read Points' lets you replace the active curve data points from the data in a text file called a .ht file. The context menu operation 'Save Points' lets you save the active data points to a .ht text file. These options are available only if the Thickness Definition property in the details view for the camberline is set to `User Specified`.

The first line in the .ht file specifies the number of points. Subsequent lines in the file, one for each data point, contain the point coordinate values 'h, t', where 'h' is the horizontal or X axis value and 't' is the thickness value. The point coordinates correspond to the defining points for the thickness definition curve in the length unit being used in DesignModeler, versus m-prime, % m-prime, m or % m.

When reading the .ht file, the data point coordinates will be interpreted based on the selected Thickness Definition Type and the X axis type. If the X axis is set to m or % m, then the 'h' coordinates for the data points will be treated as % m values, and the values will be normalized based on the first and last data points so that the values start at zero and end at 100%. If the X axis is set to m-prime or % m-prime, then the 'h' coordinates for the data points will be converted to m-prime values by normalizing based on the first and last data points and then multiplying by the maximum m-prime on the layer. These values will then be converted to % m. The existing thickness curve data for all segments will be replaced by a single curve segment with the data from the .ht file, and the curve type will be set to 'cubic spline'.

When you choose 'Save Points', the defining points for all curve segments will be written sequentially to the file starting with the leading edge point and ending at the trailing edge point. The 'h' coordinates will be written in the value corresponding to the selected X axis type, while the thickness coordinates will be written in the value corresponding to the selected Thickness Definition Type.

#### 10.3.4.4. Converting Curves to Bezier or Spline

This feature lets you convert a curve segment in either the Angle or Thickness views to an equivalent spline or Bezier curve with a specified number of points. The new curve is an approximation of the original curve, and the error in the approximation depends on the complexity of the original curve and the specified number of points for the new curve. This operation is very helpful for simplifying a curve with many points, either because it was imported or was interpolated.

The context menu items are: 'Convert to Bezier' and 'Convert to Spline'. They are available in both the Angle and Thickness views. When choosing either of these options, you are asked to specify the number of points for the new curve in a dialog box. After clicking OK, you are required to select the curve segment to convert in the graph view. The curve will be converted immediately following your selection.

#### 10.3.4.5. Converting Angle Definition Data

If you select the CamThkDef sub-feature under a Blade feature and change the Angle Definition Type, then the angle data is converted to the new type. This conversion will try to retain the shape of the camberline by interpolation. Thirty points are used in the interpolated curve.

Release 18.2 - © ANSYS, Inc. All rights reserved.