Merge pull request #4 from Blendoit/2_coord_vs_4

2 coord vs 4

1 files changed, 110 insertions, 107 deletions

diff --git a/creator.py b/creator.py
index 78c537d..6dd3c1c 100644
--- a/creator.py
+++ b/creator.py
@@ -53,14 +53,9 @@ class Coordinates:
         self.area = float()
         # Component material
         self.material = str()
-        # Upper coordinates
-        self.x_u = []
-        self.z_u = []
-        # Lower coordinates
-        self.x_l = []
-        self.z_l = []
-        # Coordinates x_u, z_u, x_l, z_l packed in single list
-        self.coord = []
+        # Coordinates
+        self.x = []
+        self.z = []
 
         # The airfoil components know the Coordinates instance's coords
         global parent
@@ -85,10 +80,8 @@ class Coordinates:
         print('Semi-span:', self.semi_span)
         print('Mass:', self.mass)
         print(num_of_dashes * '-')
-        print('x_u the upper x-coordinates:\n', np.around(self.x_u, round))
-        print('z_u the upper z-coordinates:\n', np.around(self.z_u, round))
-        print('x_l the lower x-coordinates:\n', np.around(self.x_l, round))
-        print('z_l the lower z-coordinates:\n', np.around(self.z_l, round))
+        print('x-coordinates:\n', np.around(self.x, round))
+        print('z-coordinates:\n', np.around(self.z, round))
         return None
 
     def info_save(self, save_path, number):
@@ -112,7 +105,18 @@ class Coordinates:
 
 
 class Airfoil(Coordinates):
-    '''This class enables the creation of a single NACA airfoil.'''
+    '''
+    This class enables the creation of a single NACA airfoil.
+
+    Please note: the coordinates are saved as two lists
+    for the x- and z-coordinates. The coordinates start at
+    the leading edge, travel over the airfoil's upper edge,
+    then loop back to the leading edge via the lower edge.
+
+    This method was chosen for easier future exports
+    to 3D CAD packages like SolidWorks, which can import such
+    geometry as coordinates written in a CSV file.
+    '''
 
     def __init__(self):
         global parent
@@ -122,7 +126,7 @@ class Airfoil(Coordinates):
         self.naca_num = int()
         # Mean camber line
         self.x_c = []
-        self.y_c = []
+        self.z_c = []
 
     def add_naca(self, naca_num):
         '''
@@ -148,22 +152,22 @@ class Airfoil(Coordinates):
 
         def get_camber(x):
             '''
-            Returns camber y-coordinate from 1 'x' along the airfoil chord.
+            Returns camber z-coordinate from 1 'x' along the airfoil chord.
             '''
-            y_c = float()
+            z_c = float()
             if 0 <= x < p_c:
-                y_c = (m / (p ** 2)) * (2 * p * (x / self.chord)
+                z_c = (m / (p ** 2)) * (2 * p * (x / self.chord)
                                         - (x / self.chord) ** 2)
             elif p_c <= x <= self.chord:
-                y_c = (m / ((1 - p) ** 2)) * ((1 - 2 * p)
+                z_c = (m / ((1 - p) ** 2)) * ((1 - 2 * p)
                                               + 2 * p * (x / self.chord)
                                               - (x / self.chord) ** 2)
-            return (y_c * self.chord)
+            return (z_c * self.chord)
 
         def get_thickness(x):
-            '''
-            Returns thickness from 1 'x' along the airfoil chord.
-            '''
+            '''Returns thickness from 1 'x' along the airfoil chord.'''
+
+            x = 0 if x < 0 else x
             y_t = 5 * t * self.chord * (
                 + 0.2969 * sqrt(x / self.chord)
                 - 0.1260 * (x / self.chord)
@@ -173,37 +177,43 @@ class Airfoil(Coordinates):
             return y_t
 
         def get_theta(x):
-            dy_c = float()
+            dz_c = float()
             if 0 <= x < p_c:
-                dy_c = ((2 * m) / p ** 2) * (p - x / self.chord)
+                dz_c = ((2 * m) / p ** 2) * (p - x / self.chord)
             elif p_c <= x <= self.chord:
-                dy_c = (2 * m) / ((1 - p) ** 2) * (p - x / self.chord)
-            theta = atan(dy_c)
+                dz_c = (2 * m) / ((1 - p) ** 2) * (p - x / self.chord)
+            theta = atan(dz_c)
             return theta
 
         def get_upper_coord(x):
-            x_u = x - get_thickness(x) * sin(get_theta(x))
-            z_u = get_camber(x) + get_thickness(x) * cos(get_theta(x))
-            return (x_u, z_u)
+            x = x - get_thickness(x) * sin(get_theta(x))
+            z = get_camber(x) + get_thickness(x) * cos(get_theta(x))
+            return (x, z)
 
         def get_lower_coord(x):
-            x_l = x + get_thickness(x) * sin(get_theta(x))
-            z_l = get_camber(x) - get_thickness(x) * cos(get_theta(x))
-            return (x_l, z_l)
+            x = x + get_thickness(x) * sin(get_theta(x))
+            z = get_camber(x) - get_thickness(x) * cos(get_theta(x))
+            return (x, z)
 
         # Densify x-coordinates 10 times for first 1/4 chord length
         x_chord_25_percent = round(self.chord / 4)
-        x_chord = [x / 10 for x in range(x_chord_25_percent * 10)]
-        x_chord.extend([x for x in range(x_chord_25_percent, self.chord + 1)])
+
+        x_chord = [i / 10 for i in range(x_chord_25_percent * 10)]
+        x_chord.extend(i for i in range(x_chord_25_percent, self.chord + 1))
+        # Reversed list for our lower airfoil coordinate densification
+        x_chord_rev = [i for i in range(self.chord, x_chord_25_percent, -1)]
+        extend = [i / 10 for i in range(x_chord_25_percent * 10, -1, -1)]
+        x_chord_rev.extend(extend)
 
         # Generate our airfoil geometry from previous sub-functions.
         for x in x_chord:
             self.x_c.append(x)
-            self.y_c.append(get_camber(x))
-            self.x_u.append(get_upper_coord(x)[0])
-            self.z_u.append(get_upper_coord(x)[1])
-            self.x_l.append(get_lower_coord(x)[0])
-            self.z_l.append(get_lower_coord(x)[1])
+            self.z_c.append(get_camber(x))
+            self.x.append(get_upper_coord(x)[0])
+            self.z.append(get_upper_coord(x)[1])
+        for x in x_chord_rev:
+            self.x.append(get_lower_coord(x)[0])
+            self.z.append(get_lower_coord(x)[1])
         return None
 
     def add_mass(self, mass):
@@ -211,8 +221,8 @@ class Airfoil(Coordinates):
 
     def info_print(self, round):
         super().info_print(round)
-        print('x_c the camber x-coordinates:\n', np.around(self.x_u, round))
-        print('z_c the camber z-coordinates:\n', np.around(self.x_u, round))
+        print('x_c the camber x-coordinates:\n', np.around(self.x, round))
+        print('z_c the camber z-coordinates:\n', np.around(self.x, round))
         return None
 
 
@@ -223,35 +233,33 @@ class Spar(Coordinates):
     def __init__(self):
         super().__init__(parent.chord, parent.semi_span)
 
-    def add_coord(self, airfoil, spar_x):
+    def add_coord(self, airfoil, x_loc_percent):
         '''
         Add a single spar at the % chord location given to function.
 
         Parameters:
-        coordinates: provided by Airfoil.coordinates[x_u, z_u, x_l, z_l].
+        coordinates: provided by Airfoil.coordinates[x, z, x, z].
         material: spar's material. Assumes homogeneous material.
         spar_x: spar's location as a % of total chord length.
 
         Return:
         None
         '''
-        # Airfoil surface coordinates
-        # unpacked from 'coordinates' (list of lists in 'Coordinates').
-        x_u = airfoil.x_u
-        z_u = airfoil.z_u
-        x_l = airfoil.x_l
-        z_l = airfoil.z_l
+
         # Scaled spar location with regards to chord
-        loc = spar_x * self.chord
-        # bisect_left: returns index of first value in x_u > loc.
-        # Ensures that the spar coordinates intersect with airfoil surface.
-        spar_x_u = bi.bisect_left(x_u, loc)  # index of spar's x_u
-        spar_x_l = bi.bisect_left(x_l, loc)  # index of spar's x_l
-        # These x and y coordinates are assigned to the spar, NOT airfoil.
-        self.x_u.append(x_u[spar_x_u])
-        self.z_u.append(z_u[spar_x_u])
-        self.x_l.append(x_l[spar_x_l])
-        self.z_l.append(z_l[spar_x_l])
+        loc = x_loc_percent * self.chord
+        # bi.bisect_left: returns index of first value in airfoil.x > loc
+        # This ensures that spar geom intersects with airfoil geom.
+        # Spar upper coordinates
+        spar_x = bi.bisect_left(airfoil.x, loc) - 1
+        x = [airfoil.x[spar_x]]
+        z = [airfoil.z[spar_x]]
+        # Spar lower coordinates
+        spar_x = bi.bisect_left(airfoil.x[::-1], loc) - 1
+        x += [airfoil.x[-spar_x]]
+        z += [airfoil.z[-spar_x]]
+        self.x.append(x)
+        self.z.append(z)
         return None
 
     def add_spar_caps(self, spar_cap_area):
@@ -259,7 +267,7 @@ class Spar(Coordinates):
         return None
 
     def add_mass(self, mass):
-        self.mass = len(self.x_u) * mass
+        self.mass = len(self.x) * mass
         return None
 
 
@@ -291,44 +299,44 @@ class Stringer(Coordinates):
         '''
 
         # Find distance between leading edge and first upper stringer
-        interval = airfoil.spar.x_u[0] / (stringer_u_1 + 1)
-        # initialise first self.stringer_x_u at first interval
+        interval = airfoil.spar.x[0][0] / (stringer_u_1 + 1)
+        # initialise first self.stringer_x at first interval
         x = interval
         # Add upper stringers from leading edge until first spar.
         for _ in range(0, stringer_u_1):
-            # Index of the first value of airfoil_x_u > x
-            index = bi.bisect_left(airfoil.x_u, x)
-            self.x_u.append(airfoil.x_u[index])
-            self.z_u.append(airfoil.z_u[index])
+            # Index of the first value of airfoil.x > x
+            i = bi.bisect_left(airfoil.x, x)
+            self.x.append(airfoil.x[i])
+            self.z.append(airfoil.z[i])
             x += interval
         # Add upper stringers from first spar until last spar
         # TODO: stringer placement if only one spar is created
-        interval = (airfoil.spar.x_u[-1]
-                    - airfoil.spar.x_u[0]) / (stringer_u_2 + 1)
-        x = interval + airfoil.spar.x_u[0]
+        interval = (airfoil.spar.x[-1][0]
+                    - airfoil.spar.x[0][0]) / (stringer_u_2 + 1)
+        x = interval + airfoil.spar.x[0][0]
         for _ in range(0, stringer_u_2):
-            index = bi.bisect_left(airfoil.x_u, x)
-            self.x_u.append(airfoil.x_u[index])
-            self.z_u.append(airfoil.z_u[index])
+            i = bi.bisect_left(airfoil.x, x)
+            self.x.append(airfoil.x[i])
+            self.z.append(airfoil.z[i])
             x += interval
 
         # Find distance between leading edge and first lower stringer
-        interval = airfoil.spar.x_l[0] / (stringer_l_1 + 1)
+        interval = airfoil.spar.x[0][1] / (stringer_l_1 + 1)
         x = interval
         # Add lower stringers from leading edge until first spar.
         for _ in range(0, stringer_l_1):
-            index = bi.bisect_left(airfoil.x_l, x)
-            self.x_l.append(airfoil.x_l[index])
-            self.z_l.append(airfoil.z_l[index])
+            i = bi.bisect_left(airfoil.x[::-1], x)
+            self.x.append(airfoil.x[-i])
+            self.z.append(airfoil.z[-i])
             x += interval
         # Add lower stringers from first spar until last spar
-        interval = (airfoil.spar.x_l[-1]
-                    - airfoil.spar.x_l[0]) / (stringer_l_2 + 1)
-        x = interval + airfoil.spar.x_l[0]
+        interval = (airfoil.spar.x[-1][1]
+                    - airfoil.spar.x[0][1]) / (stringer_l_2 + 1)
+        x = interval + airfoil.spar.x[0][1]
         for _ in range(0, stringer_l_2):
-            index = bi.bisect_left(airfoil.x_l, x)
-            self.x_l.append(airfoil.x_l[index])
-            self.z_l.append(airfoil.z_l[index])
+            i = bi.bisect_left(airfoil.x[::-1], x)
+            self.x.append(airfoil.x[-i])
+            self.z.append(airfoil.z[-i])
             x += interval
         return None
 
@@ -337,7 +345,7 @@ class Stringer(Coordinates):
         return None
 
     def add_mass(self, mass):
-        self.mass = len(self.x_u) * mass + len(self.x_l) * mass
+        self.mass = len(self.x) * mass + len(self.x) * mass
         return None
 
     def info_print(self, round):
@@ -357,38 +365,33 @@ def plot_geom(airfoil):
     plt.plot(airfoil.chord / 4, 0, '.', color='g',
              markersize=24, label='Quarter-chord')
     # Plot mean camber line
-    plt.plot(airfoil.x_c, airfoil.y_c,
-             '-.', color='r', linewidth='2',
+    plt.plot(airfoil.x_c, airfoil.z_c, '-.', color='r', linewidth='2',
              label='Mean camber line')
-    # Plot upper surface
-    plt.plot(airfoil.x_u, airfoil.z_u,
-             '', color='b', linewidth='1')
-    # Plot lower surface
-    plt.plot(airfoil.x_l, airfoil.z_l,
-             '', color='b', linewidth='1')
+    # Plot airfoil surfaces
+    plt.fill(airfoil.x, airfoil.z, color='b', linewidth='1', fill=False)
 
     # Plot spars
-    for _ in range(0, len(airfoil.spar.x_u)):
-        x = (airfoil.spar.x_u[_], airfoil.spar.x_l[_])
-        y = (airfoil.spar.z_u[_], airfoil.spar.z_l[_])
-        plt.plot(x, y, '.-', color='b')
-
-    # Plot upper stringers
-    for _ in range(0, len(airfoil.stringer.x_u)):
-        x = airfoil.stringer.x_u[_]
-        y = airfoil.stringer.z_u[_]
-        plt.plot(x, y, '.', color='y', markersize=12)
-    # Plot lower stringers
-    for _ in range(0, len(airfoil.stringer.x_l)):
-        x = airfoil.stringer.x_l[_]
-        y = airfoil.stringer.z_l[_]
-        plt.plot(x, y, '.', color='y', markersize=12)
+    try:
+        for _ in range(len(airfoil.spar.x)):
+            x = (airfoil.spar.x[_])
+            y = (airfoil.spar.z[_])
+            plt.plot(x, y, '-', color='b')
+    except AttributeError:
+        print('No spars to plot.')
+    # Plot stringers
+    try:
+        for _ in range(0, len(airfoil.stringer.x)):
+            x = airfoil.stringer.x[_]
+            y = airfoil.stringer.z[_]
+            plt.plot(x, y, '.', color='y', markersize=12)
+    except AttributeError:
+        print('No stringers to plot.')
 
     # Graph formatting
     plt.xlabel('X axis')
     plt.ylabel('Z axis')
 
-    plot_bound = airfoil.x_u[-1]
+    plot_bound = max(airfoil.x)
     plt.xlim(- 0.10 * plot_bound, 1.10 * plot_bound)
     plt.ylim(- (1.10 * plot_bound / 2), (1.10 * plot_bound / 2))
     plt.gca().set_aspect('equal', adjustable='box')