
import numpy as np
import matplotlib.pyplot as plt
import math
from ipywidgets import interact, IntSlider, fixed


def airfoilNACA(m,p,t,c,n):
    m = m / 100
    p = p / 10
    t = t / 100

    # x distribution (cosine spacing)
    theta = np.linspace(0, np.pi, n)
    x = 0.5 * c * (1 - np.cos(theta))
    x_hat = x / c  # normalized x

    # Thickness distribution
    yt = 5 * t * ( 0.2969 * np.sqrt(x_hat) - 0.1260 * x_hat - 0.3516 * x_hat**2 + 0.2843 * x_hat**3 - 0.1015 * x_hat**4 )

    # Camber line and slope
    z = np.zeros_like(x)
    dzdx = np.zeros_like(x)

    for i in range(len(x)):
        if x_hat[i] < p and p != 0:
            z[i] = (m / p**2) * (2 * p * x_hat[i] - x_hat[i]**2)
            dzdx[i] = (2 * m / p**2) * (p - x_hat[i])
        elif p != 0:
            z[i] = (m / (1 - p)**2) * ((1 - 2 * p) + 2 * p * x_hat[i] - x_hat[i]**2)
            dzdx[i] = (2 * m / (1 - p)**2) * (p - x_hat[i])

    beta = np.arctan(dzdx)

    # Upper and lower airfoil coordinates
    xu = x - yt * np.sin(beta)
    yu = z + yt * np.cos(beta)
    xl = x + yt * np.sin(beta)
    yl = z - yt * np.cos(beta)

    # Combine and plot
    x_total = np.concatenate([xu[::-1], xl[1:]])
    y_total = np.concatenate([yu[::-1], yl[1:]])

    plt.figure(figsize=(10, 4))
    plt.plot(x_total, y_total, 'k-', linewidth=1.5, label="Airfoil")
    plt.plot(x, z, 'r--', linewidth=1.2, label="Camber line")
    plt.axis('equal')
    plt.title(f"NACA {m*100:.0f}{p*10:.0f}{t*100:.0f}")
    plt.xlabel("x/c")
    plt.ylabel("y/c")
    plt.grid(True)
    plt.legend()
    plt.show()

    return x_total, y_total

# Airfoil function
def plot_airfoil(m,p,t,c,n):
    airfoilNACA(m,p,t,c,n)   # ignoramos el return

# Interactive sliders
interact(
    plot_airfoil,
    m=IntSlider(min=0, max=9, step=1, value=2, description="m"),
    p=IntSlider(min=0, max=9, step=1, value=4, description="p"),
    t=IntSlider(min=10, max=40, step=1, value=12, description="t"),
    c=fixed(1.0),  # cuerda
    n=fixed(200)   # número de puntos
)

plot_airfoildef plot_airfoil(m, p, t, c, n)

/tmp/ipython-input-537601517.py<no docstring>

Generador de un perfil NACA de 4 dígitos¶