Inclusion of Shaft and Propeller classes with tests (basic version) (#62)

* Inclusion of Shaft and Propeller classes with tests (basic version)

Author: ggurioli

bladex/__init__.py

@@ -1,11 +1,13 @@
 """
 BladeX init
 """
-__all__ = ['profilebase', 'profiles', 'blade', 'deform', 'params', 'ndinterpolator']
+__all__ = ['profilebase', 'profiles', 'blade', 'shaft', 'propeller', 'deform', 'params', 'ndinterpolator']
 
 from .profilebase import ProfileBase
 from .profiles import CustomProfile, NacaProfile
 from .blade import Blade
+from .shaft import Shaft
+from .propeller import Propeller
 from .deform import Deformation
 from .params import ParamFile
-from .ndinterpolator import RBF, reconstruct_f, scipy_bspline
+from .ndinterpolator import RBF, reconstruct_f, scipy_bspline

bladex/blade.py

@@ -226,22 +226,22 @@ def _planar_to_cylindrical(self):
             - :math:`y = r \\sin\\left( \\frac{y_i}{r} \\right) \\qquad
               \\forall y_i \\in Y`
 
-            - :math:`z = -r \\cos\\left( \\frac{y_i}{r} \\right) \\qquad
+            - :math:`z = r \\cos\\left( \\frac{y_i}{r} \\right) \\qquad
               \\forall y_i \\in Y`
 
         After transformation, the method also fills the numpy.ndarray
         "blade_coordinates_up" and "blade_coordinates_down" with the new
         :math:`(X, Y, Z)` coordinates.
         """
-        for section, radius in zip(self.sections, self.radii):
+        for section, radius in zip(self.sections[::-1], self.radii[::-1]):
             theta_up = section.yup_coordinates / radius
             theta_down = section.ydown_coordinates / radius
 
             y_section_up = radius * np.sin(theta_up)
             y_section_down = radius * np.sin(theta_down)
 
-            z_section_up = -radius * np.cos(theta_up)
-            z_section_down = -radius * np.cos(theta_down)
+            z_section_up = radius * np.cos(theta_up)
+            z_section_down = radius * np.cos(theta_down)
 
             self.blade_coordinates_up.append(
                 np.array([section.xup_coordinates, y_section_up, z_section_up]))
@@ -464,7 +464,7 @@ def plot(self, elev=None, azim=None, ax=None, outfile=None):
         else:
             fig = plt.figure()
             ax = fig.gca(projection=Axes3D.name)
-        ax.set_aspect('equal')
+        ax.set_aspect('auto')
 
         for i in range(self.n_sections):
             ax.plot(self.blade_coordinates_up[i][0],
@@ -474,7 +474,7 @@ def plot(self, elev=None, azim=None, ax=None, outfile=None):
                     self.blade_coordinates_down[i][1],
                     self.blade_coordinates_down[i][2])
 
-        plt.axis('equal')
+        plt.axis('auto')
         ax.set_xlabel('X axis')
         ax.set_ylabel('Y axis')
         ax.set_zlabel('radii axis')
@@ -862,7 +862,7 @@ def generate_iges(self,
                 display.DisplayShape(self.generated_root, update=True)
             start_display()
 
-    def generate_blade_solid(self,
+    def generate_solid(self,
                              max_deg=1,
                              display=False,
                              errors=None):

bladex/propeller.py

@@ -0,0 +1,85 @@
+"""
+Module for the propeller with shaft bottom-up parametrized construction.
+"""
+import os
+import numpy as np
+from bladex import Blade, Shaft
+import OCC.Core.TopoDS
+from OCC.Core.gp import gp_Dir, gp_Pnt, gp_Ax1, gp_Trsf
+from OCC.Core.IGESControl import IGESControl_Reader, IGESControl_Writer
+from OCC.Core.BRepBuilderAPI import BRepBuilderAPI_Transform, BRepBuilderAPI_Sewing
+from OCC.Core.BRepAlgoAPI import BRepAlgoAPI_Fuse
+from OCC.Extend.DataExchange import write_stl_file
+from OCC.Display.SimpleGui import init_display
+
+class Propeller(object):
+    """
+    Bottom-up parametrized propeller (including shaft) construction.
+    The constructor requires PythonOCC to be installed.
+
+    :param shaft.Shaft shaft: shaft to be added to the propeller
+    :param blade.Blade blade: blade of the propeller
+    :param int n_blades: number of blades composing the propeller
+    :cvar OCC.Core.TopoDS.TopoDS_Solid shaft_solid: solid shaft
+    :cvar OCC.Core.TopoDS.TopoDS_Shell sewed_full_body: propeller with shaft shell
+    """
+
+    def __init__(self, shaft, blade, n_blades):
+        self.shaft_solid = shaft.generate_solid()
+        blade.apply_transformations(reflect=True)
+        blade_solid = blade.generate_solid(max_deg=2, 
+                                           display=False, 
+                                           errors=None)
+        blades = []
+        blades.append(blade_solid)
+        for i in range(n_blades-1):
+            blade.rotate(rad_angle=1.0*2.0*np.pi/float(n_blades))
+            blade_solid = blade.generate_solid(max_deg=2, display=False, errors=None)
+            blades.append(blade_solid)
+        blades_combined = blades[0]
+        for i in range(len(blades)-1):
+            boolean_union = BRepAlgoAPI_Fuse(blades_combined, blades[i+1])
+            boolean_union.Build()
+            if not boolean_union.IsDone():
+                raise RuntimeError('Unsuccessful assembling of blade')
+            blades_combined = boolean_union.Shape()
+        boolean_union = BRepAlgoAPI_Fuse(self.shaft_solid, blades_combined)
+        boolean_union.Build()
+        result_compound = boolean_union.Shape()
+        section_edges = boolean_union.SectionEdges()
+        sewer = BRepBuilderAPI_Sewing(1e-2)
+        sewer.Add(result_compound)
+        sewer.Perform()
+        self.sewed_full_body = sewer.SewedShape()
+
+    def generate_iges(self, filename):
+        """
+        Export the .iges CAD for the propeller with shaft.
+
+        :param string filename: path (with the file extension) where to store 
+            the .iges CAD for the propeller and shaft
+        :raises RuntimeError: if the solid assembling of blades is not 
+            completed successfully
+        """
+        iges_writer = IGESControl_Writer()
+        iges_writer.AddShape(self.sewed_full_body)
+        iges_writer.Write(filename)
+
+    def generate_stl(self, filename):
+        """
+        Export the .stl CAD for the propeller with shaft.
+
+        :param string filename: path (with the file extension) where to store 
+            the .stl CAD for the propeller and shaft
+        :raises RuntimeError: if the solid assembling of blades is not 
+            completed successfully
+        """
+        write_stl_file(self.sewed_full_body, filename)
+
+    def display(self):
+        """
+        Display the propeller with shaft.
+        """
+        display, start_display, add_menu, add_function_to_menu = init_display()
+        display.DisplayShape(self.sewed_full_body, update=True)
+        start_display()

bladex/shaft.py

@@ -0,0 +1,52 @@
+import os
+from OCC.Core.IGESControl import IGESControl_Reader
+from OCC.Core.BRepBuilderAPI import BRepBuilderAPI_MakeSolid, BRepBuilderAPI_Sewing
+import OCC.Core.TopoDS
+from OCC.Display.SimpleGui import init_display
+
+class Shaft(object):
+    """
+    Bottom-up parametrized shaft construction.
+
+    :param string filename: path (with the file extension) of a .iges file with 
+        stored shaft information.
+    :cvar string filename: path (with the file extension) of a .iges file with 
+        stored shaft information.
+    """
+
+    def __init__(self, filename):
+        self.filename = filename
+
+    def generate_solid(self):
+        """
+        Generate an assembled solid shaft using the BRepBuilderAPI_MakeSolid  
+        algorithm. This method requires PythonOCC to be installed.
+
+        :raises RuntimeError: if the assembling of the solid shaft is not 
+            completed successfully
+        :return: solid shaft
+        :rtype: OCC.Core.TopoDS.TopoDS_Solid
+        """
+        iges_reader = IGESControl_Reader()
+        iges_reader.ReadFile(self.filename)
+        iges_reader.TransferRoots()
+        shaft_compound = iges_reader.Shape()
+        sewer = BRepBuilderAPI_Sewing(1e-2)
+        sewer.Add(shaft_compound)
+        sewer.Perform()
+        result_sewed_shaft = sewer.SewedShape()
+        shaft_solid_maker = BRepBuilderAPI_MakeSolid()
+        shaft_solid_maker.Add(OCC.Core.TopoDS.topods_Shell(result_sewed_shaft))
+        if not shaft_solid_maker.IsDone():
+            raise RuntimeError('Unsuccessful assembling of solid shaft')
+        shaft_solid = shaft_solid_maker.Solid()
+        return shaft_solid
+
+    def display(self):
+        """
+        Display the shaft.
+        """
+        shaft_solid = self.generate_solid()
+        display, start_display, add_menu, add_function_to_menu = init_display()
+        display.DisplayShape(shaft_solid, update=True)
+        start_display()

tests/test_blade.py

@@ -776,28 +776,28 @@ def test_stl_smesh_export_exception(self):
         with self.assertRaises(ValueError):
             blade.generate_stl_smesh(min_length=1, max_length=10, outfile_stl=55)
 
-    def test_blade_solid_max_deg_exception(self):
+    def test_solid_max_deg_exception(self):
         blade = create_sample_blade_NACA()
         blade.apply_transformations()
         with self.assertRaises(ValueError):
-            blade.generate_blade_solid(
+            blade.generate_solid(
                 max_deg=-1,
                 display=False,
                 errors=None)
 
-    def test_blade_solid_errors_exception(self):
+    def test_solid_errors_exception(self):
         blade = create_sample_blade_NACA()
         blade.apply_transformations()
         with self.assertRaises(ValueError):
-            blade.generate_blade_solid(
+            blade.generate_solid(
                 max_deg=-1,
                 display=False,
                 errors='tests/test_datasets/errors')
 
-    def test_generate_blade_solid(self):
+    def test_generate_solid(self):
         blade = create_sample_blade_NACA()
         blade.apply_transformations()
-        blade_solid = blade.generate_blade_solid(max_deg=2, display=False, 
+        blade_solid = blade.generate_solid(max_deg=2, display=False, 
                                                  errors=None)
         self.assertIsInstance(blade_solid, TopoDS_Solid)