update SHARPy docs and readme with fuselage module

README.md

@@ -44,7 +44,7 @@ wings and wind turbines. In addition, it supports linearisation of these nonline
 arbitrary conditions and includes various tools such as: model reduction or frequency analysis.
 
 In short, SHARPy offers (amongst others) the following solutions to the user:
-* Static aerodynamic, structural and aeroelastic solutions
+* Static aerodynamic, structural and aeroelastic solutions including fuselage effects
 * Finding trim conditions for aeroelastic configurations
 * Nonlinear, dynamic time domain simulations under a large number of conditions such as:
     + Prescribed trajectories.

docs/source/content/casefiles.rst

@@ -321,6 +321,55 @@ Item by item:
     should be included for each airfoil defined. Each entry consists of a 4-column table. The first column corresponds
     to the angle of attack (in radians) and then the ``C_L``, ``C_D`` and ``C_M``. 
 
+Nonlifting Body file
+-----------------
+
+All the nonlifting body data is contained in ``case.nonlifting_body.h5``.
+
+The idea behind the structure of the model definition of nonlifting bodies in SHARPy is similiar to the aerodynamic 
+one for lifting surfaces. Again for each node or element we define several parameters.
+
+Item by item:
+
+* ``shape``: Type of geometrical form of 3D nonlifting body.
+
+    In the ``nonlifting_body.h5`` file, there is a Group called ``shape``. The shape indicates the geometrical form of the 
+    nonlifting body. Common options for this parameter are ``'cylindrical'`` and ``'specific'``. For the former, SHARPy 
+    expects rotational symmetric cross-section for which only a radius is required for each node. For the ``'specific'`` 
+    option, SHARPy can create a more unique nonlifting body geometry by creating an ellipse at each fuselage defined by 
+    :math:`\frac{y^2}{a^2}+\frac{z^2}{b^2}=1` with the given ellipse axis lengths :math:`a`  and :math:`b`. Further, SHARPy 
+    lets define the user to create a vertical offset from the node with :math:`z_0`.
+
+* ``radius [num_node]``: Cross-sectional radius.
+
+    Is an array with the radius of specified for each fuselage node.
+
+* ``a_ellipse [num_node]``: Elliptical axis lengths along the local y-axis.
+
+    Is an array with the length of the elliptical axis along the y-axis.
+
+* ``b_ellipse [num_node]``: Elliptical axis lengths along the local z-axis.
+
+    Is an array with the length of the elliptical axis along the z-axis.
+
+* ``z_0_ellipse [num_node]``: Vertical offset of the ellipse center from the beam node.
+
+    Is an array with the vertical offset of the center of the elliptical cross-sectoin from the fuselage node.
+
+*  ``surface_m [num_surfaces]``: Radial panelling.
+
+    Is an integer array with the number of radial panels for every surface.
+
+*  ``nonlifting_body_node [num_node]``: Nonlifting body node definition.
+
+    Is a boolean (``True`` or ``False``) array that indicates if that node has a nonlifting body
+    attached to it.
+
+*  ``surface_distribution [num_elem]``:  Nonlifting Surface integer array.
+
+    It contains the index of the surface the element belongs to. Surfaces need to be continuous, so please note 
+    that if your beam numbering is not continuous, you need to make a surface per continuous section.
+
 
 Time-varying force input file (``.dyn.h5``)
 -------------------------------------------

docs/source/index.rst

@@ -29,7 +29,7 @@ SHARPy is an aeroelastic analysis package currently under development at the Dep
 Imperial College London. It can be used for the structural, aerodynamic, aeroelastic and flight dynamics
 analysis of flexible aircraft, flying wings and wind turbines. Amongst other capabilities_, it offers the following solutions to the user:
 
-* Static aerodynamic, structural and aeroelastic solutions
+* Static aerodynamic, structural and aeroelastic solutions including fuselage effects
 * Finding trim conditions for aeroelastic configurations
 * Nonlinear, dynamic time domain simulations under a large number of conditions such as: