BladeMesher Components
----------------------

The following sections describe the components used to generate the blade mesh.

.. _sec-coonsbladeroot:

CoonsBladeRoot
^^^^^^^^^^^^^^

The :class:`PGL.components.bladeroot.CoonsBladeRoot` class generates a cylindrical surface where one end can be joined to form a 2, 3, or four-bladed rotors.

Generating a blade root is simple, requiring only the curve connecting to the main blade section:

.. literalinclude:: ../PGL/examples/bladeroot_example.py

.. _coonsroot-fig:

.. figure:: /figures/bladeroot.*
    :align: center


.. _sec-coonsbladetip:

CoonsBladeTip
^^^^^^^^^^^^^

The :class:`PGL.components.bladetip.CoonsBladeTip` class generates a blade tip surface mesh directly useable in a CFD rotor surface mesh.

Generating a blade tip requires a few more inputs than the root, since we can control the shape of the tip using a number of blending factors that control the tip thickness and planform.
To ensure a smooth transition from the main blade section to the tip, the main surface is also a needed input.

Extending the ``CoonsBlade`` example script we add the blade tip:

.. literalinclude:: ../PGL/examples/coonstip_example.py
    :start-after: # --- 1
    :end-before: # --- 2

.. _coonstip-fig:

.. figure:: /figures/bladetip.*
    :align: center

Changing the control parameters and position of the tip point can alter the shape of the tip considerably.

.. _coonstip-fig:

.. figure:: /figures/bladetip_mod.*
    :align: center

You can to a modest extent also place the tip point out of the y-plane, however, it is recommended to instead introduce winglet-like shapes into the main blade section, and simply fit the tip component to this.

.. _coonstip-fig:

.. figure:: /figures/bladetip_mod1.*
    :align: center


.. _sec-loftedbladesurface:

LoftedBladeSurface
^^^^^^^^^^^^^^^^^^

The :class:`PGL.components.loftedblade.LoftedBladeSurface` class builds a blade surface based on a planform definition and an airfoil family.

The example in ``examples/loftedblade_example.py`` shows the basic usage of this class:

.. literalinclude:: ../PGL/examples/loftedblade_example.py


.. _sec-coonsnacelle:

CoonsNacelle
^^^^^^^^^^^^

The :class:`PGL.components.nacelle.CoonsNacelle` class builds a rotationally symmetric spinner and nacelle surface that attaches to the blade root, replacing the simpler ``CoonsBladeRoot``.

.. figure:: /figures/nacelle.*
    :align: center





.. _sec-coonsblade:

CoonsBlade
^^^^^^^^^^

The :class:`PGL.components.coonsblade.CoonsBlade` class uses the :class:`PGL.main.extruded_section.ExtrudedSection` to generate a full blade surface.
In the example shown below we also use the :class:`PGL.components.airfoil.BlendAirfoilShapes` to create interpolated airfoil cross-sections along the blade.

.. literalinclude:: ../PGL/examples/coonsblade_example.py

As you can see the blade is generated by adding a number of cross-sections along the span, with a given chord, rotation and so-called pitch axis aft leading edge.
The two additional parameters ``dp`` and ``fWs`` control the gradient of the span-wise edge curves at the sections, and the distance of the Bezier control points from the sections.

Running the example should generate a surface that looks like this:

.. _coonsblade-fig:

.. figure:: /figures/coonsblade.*
    :align: center