Added possibility to specify thickness and camber max for each radius in the blade __init__ method. To do so, corresponding methods in baseprofile implemented. Added tests too

Author: DavideOberto

bladex/blade.py

@@ -84,6 +84,10 @@ class Blade(object):
         radial section of the blade.
     :param array_like skew_angles: 1D array, contains the skew angles
         (in degrees) for each radial section of the blade.
+    :param array_like thickness: 1D array, contains the value of the
+        thickness of each section, specified if sections have not the desired thickness.
+    :param array_like camber: 1D array, contains the value of the
+        camber of each section, specified if sections have note the desired camber.
 
     Note that, each of the previous array_like parameters must be consistent
     with the other parameters in terms of the radial ordering of the blade
@@ -149,7 +153,7 @@ class Blade(object):
     """
 
     def __init__(self, sections, radii, chord_lengths, pitch, rake,
-                 skew_angles):
+                 skew_angles, thickness=None, camber=None):
         # Data are given in absolute values
         self.sections = sections
         self.n_sections = len(sections)
@@ -158,6 +162,8 @@ def __init__(self, sections, radii, chord_lengths, pitch, rake,
         self.pitch = pitch
         self.rake = rake
         self.skew_angles = skew_angles
+        self.thickness = thickness
+        self.camber = camber
         self._check_params()
 
         self.conversion_factor = 1000  # to convert units if necessary
@@ -328,12 +334,20 @@ def apply_transformations(self, reflect=True):
             # Translate reference point into origin
             self.sections[i].translate(-self.sections[i].reference_point)
 
-            if reflect:
-                self.sections[i].reflect()
-
             # Scale the unit chord to actual length.
             self.sections[i].scale(self.chord_lengths[i])
 
+            # Setting thickness max is required
+            if self.thickness is not None:
+                self.sections[i].set_thickness_max(self.thickness[i])
+                
+            # Setting camber max is required
+            if self.camber is not None and i < self.n_sections-1:
+                self.sections[i].set_camber_line_max(self.camber[i])
+
+            if reflect:
+                self.sections[i].reflect()
+
             # Rotate according to the pitch angle.
             # Since the current orientation system is not standard (It is
             # left-handed Cartesian orientation system, where Y-axis points

bladex/profile/baseprofile.py

@@ -379,9 +379,6 @@ def deform_camber_line(self, percent_change, n_interpolated_points=None):
 
         :param float percent_change: percentage of change of the
             maximum camber. Default value is None
-        :param bool interpolate:  if True, the interpolated coordinates are
-            used to compute the camber line and foil's thickness, otherwise
-            the original discrete coordinates are used. Default value is False.
         :param int n_interpolated_points: number of points to be used for the
             equally-spaced sample computations. If None then there is no
             interpolation, unless the arrays x_up != x_down elementwise which
@@ -415,6 +412,50 @@ def deform_camber_line(self, percent_change, n_interpolated_points=None):
         self.yup_coordinates = self.camber_line[1] + half_thickness
         self.ydown_coordinates = self.camber_line[1] - half_thickness
 
+    def set_camber_line_max(self, camber_max):
+        """
+        Deform camber line according to a given maximum value. 
+        The percentage of camber wrt to the x/c coordinate does not change, i.e.,
+        we rescale the camber value by a scalar
+        Also reconstructs the deformed airfoil's coordinates.
+
+        Thus, the percentage of change is defined as follows:
+
+        .. math::
+            \\frac{\\text{new magnitude of max camber - old magnitude of
+            maximum \
+            camber}}{\\text{old magnitude of maximum camber}} * 100
+
+        A positive percentage means the new camber is larger than the max
+        camber value, while a negative percentage indicates the new value
+        is smaller.
+
+        We note that the method works only for airfoils in the reference
+        position, i.e. chord line lies on the X-axis and the foil is not
+        rotated, since the measurements are based on the Y-values of the
+        airfoil coordinates, hence any measurements or scalings will be
+        inaccurate for the foils not in their reference position.
+
+        :param float camber_max: maximum camber to be set.
+        """
+        old_camber_max = self.max_camber()
+        percent_scaling_factor = 100*(camber_max - old_camber_max) / (old_camber_max)  
+        # print(percent_scaling_factor)
+        self.deform_camber_line(percent_scaling_factor)
+
+    
+    def set_thickness_max(self, thickness_max):
+        """
+        Deform y_up and y_down coordinates to have the desired thickness max value.
+        To do so, we compute the ratio between olt thickness and new one
+
+        :param float thickness_max: maximum thickness to be set.
+        """
+        old_thickness = self.max_thickness()
+        ratio_thickness = thickness_max / old_thickness if old_thickness != 0. else 0.
+        self.yup_coordinates *= ratio_thickness
+        self.ydown_coordinates *= ratio_thickness
+
     @property
     def yup_curve(self):
         """

tests/test_profiles.py

@@ -14,6 +14,25 @@ def create_custom_profile():
     return CustomProfile(xup=xup, yup=yup, xdown=xdown, ydown=ydown)
 
 
+class TestBaseProfileMethods(TestCase):
+    def test_max_thickness(self):
+        profile = NacaProfile(digits='2412')
+        self.assertAlmostEqual(profile.max_thickness(), .12, delta=1e-4)
+
+    def test_set_thickness_max(self):
+        profile = NacaProfile(digits='2412')
+        profile.set_thickness_max(.24)
+        self.assertAlmostEqual(profile.max_thickness(), .24, delta=1e-4)
+
+    def test_max_camber(self):
+        profile = NacaProfile(digits='3412')
+        self.assertAlmostEqual(profile.max_camber(), .03, delta=1e-4)
+
+    def test_set_camber_max(self):
+        profile = NacaProfile(digits='3412')
+        profile.set_camber_line_max(.05)
+        self.assertAlmostEqual(profile.max_camber(), .05, delta=1e-4)
+
 class TestCustomProfile(TestCase):
     def test_inheritance_custom(self):
         self.assertTrue(issubclass(CustomProfile, ProfileInterface))