def main(output='flutter-velocity-example.pdf'):
"""
>>> import io
>>> fobj = io.BytesIO()
>>> main(fobj)
>>> assert len(fobj.getvalue()) > 0
>>> assert fobj.getvalue()[:4] == b'%PDF'
"""
zs = np.linspace(0, 20000, 200)
ps, ts, ss = model_atmosphere(zs)
rhos = (ps/1000) / (0.2869 * (ts + 273.1))
vs_t = flutter_velocity_transonic(ps, ss, 14.02, 7, 8.59, 0.5)
vs_s1 = flutter_velocity_supersonic(rhos, 5026, 11671, 0.0923, 0.0859, 0.0284, 0.0040, 4.3)
vs_s2 = flutter_velocity_supersonic(rhos, 5026, 11671, 0.0923, 0.0859, 0.0284, 0.0040, 3)
vs_s3 = flutter_velocity_supersonic(rhos, 5026, 11671, 0.0923, 0.0859, 0.0284, 0.0040, 2)
plt.figure()
#plt.plot(zs * 1e-3, vs_t, 'r', label="transonic flutter velocity")
plt.plot(zs*1e-3, vs_t/343.2, 'c', label="Theodorson")
plt.plot(zs*1e-3, vs_s1/343.2, 'g', label="Mach 4.3")
plt.plot(zs*1e-3, vs_s2/343.2, 'r', label="Mach 3")
plt.plot(zs*1e-3, vs_s3/343.2, 'b', label="Mach 2")
plt.title('Flutter velocity vs altitude, Core/Booster fin')
plt.xlabel('Altitude [km]')
plt.ylabel('Flutter Velocity [Mach]')
plt.legend()
plt.savefig(output, format='PDF')
def main(output="flutter-velocity-example.pdf"):
"""
>>> import io
>>> fobj = io.BytesIO()
>>> main(fobj)
>>> assert len(fobj.getvalue()) > 0
>>> assert fobj.getvalue()[:4] == b'%PDF'
"""
zs = np.linspace(0, 20000, 200)
ps, ts, ss = model_atmosphere(zs)
rhos = (ps / 1000) / (0.2869 * (ts + 273.1))
vs_t = flutter_velocity_transonic(ps, ss, 20, 10, 10, 0.2)
vs_s = flutter_velocity_supersonic(rhos, 380, 104, 1, 0.3, 0.0313, 0.0855, 3)
plt.figure()
plt.plot(zs * 1e-3, vs_t, "r", label="transonic flutter velocity")
plt.plot(zs * 1e-3, vs_s, "g", label="supersonic flutter velocity, Mach 3")
plt.title("Flutter velocity vs altitude")
plt.xlabel("Altitude [km]")
plt.ylabel("Flutter velocity [m/s]")
plt.legend()
plt.savefig(output, format="PDF")
def main(output='flutter-velocity-example.pdf'):
"""
>>> import io
>>> fobj = io.BytesIO()
>>> main(fobj)
>>> assert len(fobj.getvalue()) > 0
>>> assert fobj.getvalue()[:4] == b'%PDF'
"""
zs = np.linspace(0, 20000, 200)
ps, ts, ss = model_atmosphere(zs)
rhos = (ps / 1000) / (0.2869 * (ts + 273.1))
vs_t = flutter_velocity_transonic(ps, ss, 20, 10, 10, 0.2)
vs_s = flutter_velocity_supersonic(rhos, 380, 104, 1, 0.3, 0.0313, 0.0855,
3)
plt.figure()
plt.plot(zs * 1e-3, vs_t, 'r', label="transonic flutter velocity")
plt.plot(zs * 1e-3, vs_s, 'g', label="supersonic flutter velocity, Mach 3")
plt.title('Flutter velocity vs altitude')
plt.xlabel('Altitude [km]')
plt.ylabel('Flutter velocity [m/s]')
plt.legend()
plt.savefig(output, format='PDF')
