import numpy as np

def u_nandasena(b, c, C_d, C_l, rho_s, rho_w=1e3, theta=0, g=9.81, **_):
    return np.sqrt(
        (2 * (rho_s/rho_w - 1) * g * c * np.cos(np.radians(theta)))
        / C_l
    )


const = {
    "a": 4,
    "b": 2.5,
    "c": 2,
    "C_d": 1.95,
    "C_l": 0.178,
    "theta": 0,
    "rho_s": 2.7e3,
}

u = u_nandasena(**const)
u_ola = 14.5
print(f"Nandasena: u={u:5.2f}m/s")
print(f"Olaflow:   u={u_ola:5.2f}m/s")
print(f"Gap:      du={abs(u_ola - u):5.2f}m/s")
print(f"Gap:      du={abs(u_ola - u)/u:5.2%}")
print(f"Gap:      du={abs(u_ola - u)/u_ola:5.2%}")