def main():
# This function runs the vortex panel method on a NACA 2412
# Generate airfoil coordinates
airfoil_coordinates = NACA4('2412', 50)
x_airfoil = airfoil_coordinates[:, 0]
y_airfoil = airfoil_coordinates[:, 1]
# Set the angle of attack
alpha = 10
# Run the vortex panel method
x, cp, cl, cm = vortex_panel_method(alpha, airfoil_coordinates)
# Print the values of cl and cm in the terminal
print('C_l = ', cl)
print('C_m = ', cm)
# Plot the pressure distribution
plot_cp(x, cp, x_airfoil, y_airfoil)
# Plot the lift coefficient and moment coefficient versus angle of attack
plot_polar(airfoil_coordinates)
def plot_polar(coordinates, alpha_begin=-10, alpha_end=20, samples=31, use_TeX=False):
""" TODO: Add description
"""
blue = [0.118, 0.506, 0.984, 1]
#cyan = [0.129, 0.996, 0.996, 1]
#green = [0.118, 0.988, 0.133, 1]
#orange = [0.992, 0.596, 0.118, 1]
red = [0.988, 0.047, 0.082, 1]
alpha_range = np.linspace(alpha_begin, alpha_end, samples)
cl = np.zeros(np.size(alpha_range))
cm = np.zeros(np.size(alpha_range))
for i in range(np.size(alpha_range)):
x, cp, cl[i], cm[i] = vortex_panel_method(alpha_range[i], coordinates)
plt.figure(num='Lift Coefficient and Moment Coefficient versus Angle of Attack', figsize=(6, 6), dpi=100)
ax = plt.gca()
if use_TeX:
plt.rc('font', **{'family': 'serif', 'serif': ['Palatino']})
plt.rc('text', usetex=True)
# Use no labels for minor ticks
yLocator = MultipleLocator(0.1)
majorFormatter = FormatStrFormatter('%d')
xLocator = MultipleLocator(1)
ax.yaxis.set_minor_locator(yLocator)
ax.xaxis.set_minor_locator(xLocator)
# Plot the data
plt.plot(alpha_range, cl, color=blue, label=r'$C_l$')
plt.plot(alpha_range, cm, color=red, label=r'$C_m$')
plt.legend(loc='center right', frameon=False)
plt.ylabel('$C_l / C_m$ $[-]$', fontsize=16)
plt.xlabel(r'$\alpha$ $[deg]$', fontsize=16)
plt.xlim(-8, 20)
plt.ylim(-1.0, 2.5)
plt.xticks(np.linspace(-8, 20, 8))
plt.yticks(np.array([-1.0, -0.5, 0.0, 0.5, 1.0, 1.5, 2.0, 2.5]))
# Hide the right and top spines
ax.spines['right'].set_visible(False)
ax.spines['top'].set_visible(False)
# Only show ticks on the left and bottom spines
ax.spines['left'].set_position('zero')
ax.spines['bottom'].set_position('zero')
ax.yaxis.set_ticks_position('left')
ax.xaxis.set_ticks_position('bottom')
ax.xaxis.labelpad = 20
# Hide the tick label at the origin
yticks = ax.get_yticklabels()
yticks[2].set_visible(False)
xticks = ax.xaxis.get_major_ticks()
xticks[2].set_visible(False)
#plt.savefig('name.pdf', format = 'pdf', dpi = 1000, bbox_inches='tight')
plt.show()
