Section 4.5 - Venus SmallSat Aerocapture - Target EFPA Selection
[1]:
from AMAT.planet import Planet
from AMAT.vehicle import Vehicle
[2]:
# Create a planet object
planet=Planet("VENUS")
planet.h_skip = 150000.0
# Load an nominal atmospheric profile with height, temp, pressure, density data
planet.loadAtmosphereModel('../../../atmdata/Venus/venus-gram-avg.dat', 0 , 1 ,2, 3)
[3]:
ATM_height, ATM_density_low, ATM_density_avg, ATM_density_high, ATM_density_pert = planet.loadMonteCarloDensityFile2('../../../atmdata/Venus/LAT20N.txt', 0, 1, 2, 3, 4, heightInKmFlag=True)
density_int_low = planet.loadAtmosphereModel6(ATM_height, ATM_density_low, ATM_density_avg, ATM_density_high, -3.0, 151, 2)
density_int_avg = planet.loadAtmosphereModel6(ATM_height, ATM_density_low, ATM_density_avg, ATM_density_high, 0.0, 151, 2)
density_int_hig = planet.loadAtmosphereModel6(ATM_height, ATM_density_low, ATM_density_avg, ATM_density_high, +3.0, 151, 2)
[4]:
planet1 = Planet('VENUS')
planet2 = Planet('VENUS')
planet3 = Planet('VENUS')
planet1.density_int = density_int_low
planet2.density_int = density_int_avg
planet3.density_int = density_int_hig
[5]:
import numpy as np
import matplotlib.pyplot as plt
[6]:
h_array = np.linspace(0, 150e3, 1001)
d_min_arr = planet1.densityvectorized(h_array)
d_avg_arr = planet2.densityvectorized(h_array)
d_max_arr = planet3.densityvectorized(h_array)
[45]:
fig = plt.figure()
fig.set_size_inches([6.25, 5.25])
plt.rc('font',family='Times New Roman')
params = {'mathtext.default': 'regular' }
plt.rcParams.update(params)
plt.plot(d_min_arr, h_array*1E-3, 'b-', linewidth=1.0, label="Minimum "+r"$(-3\sigma)$")
plt.plot(d_avg_arr, h_array*1E-3, 'g-', linewidth=1.0, label="Average")
plt.plot(d_max_arr, h_array*1E-3, 'r-', linewidth=1.0, label="Maximum "+r"$(+3\sigma)$")
plt.xlabel("Density, kg/m3",fontsize=14)
plt.ylabel("Altitude, km",fontsize=14)
plt.xscale('log')
plt.yticks(fontsize=14)
plt.xticks(np.logspace(-10, 1, 12), fontsize=14)
plt.grid('on',linestyle='-', linewidth=0.2)
ax=plt.gca()
ax.xaxis.set_tick_params(direction='in', which='both')
ax.yaxis.set_tick_params(direction='in', which='both')
ax.xaxis.set_tick_params(width=2, length=4)
ax.yaxis.set_tick_params(width=2, length=4)
ax.xaxis.set_tick_params(width=1, length=4, which='minor')
ax.yaxis.set_tick_params(width=1, length=4, which='minor')
ax.xaxis.grid(which='major', color='k', linestyle='dotted', linewidth=0.5)
ax.xaxis.grid(which='minor', color='k', linestyle='dotted', linewidth=0.0)
ax.yaxis.grid(which='major', color='k', linestyle='dotted', linewidth=0.5)
ax.yaxis.grid(which='minor', color='k', linestyle='dotted', linewidth=0.0)
for axis in ['top', 'bottom', 'left', 'right']:
ax.spines[axis].set_linewidth(2)
plt.legend(loc='upper right', fontsize=12, framealpha=0.8)
plt.savefig('../../../data/mdpi-aerospace/smallsat-mission-concepts/venus/venus-mean-density-variations.png', dpi= 300,bbox_inches='tight')
plt.savefig('../../../data/mdpi-aerospace/smallsat-mission-concepts/venus/venus-mean-density-variations.pdf', dpi=300,bbox_inches='tight')
plt.savefig('../../../data/mdpi-aerospace/smallsat-mission-concepts/venus/venus-mean-density-variations.eps', dpi=300,bbox_inches='tight')
plt.show()
The PostScript backend does not support transparency; partially transparent artists will be rendered opaque.
Compute corridor bounds for low, avg, and high density atm
[8]:
planet.density_int = density_int_low
# Set up a vehicle object
vehicle1=Vehicle('SmallSat1', 37, 20, 0.0, 1.767, 0.0, 0.35, planet)
vehicle1.setInitialState(150.0,-6.22,23.16,10.8191,89.9982,-5.00,0.0,0.0)
vehicle1.setSolverParams(1E-6)
vehicle1.setDragModulationVehicleParams(20, 7.5)
underShootLimit, exitflag_us = vehicle1.findUnderShootLimitD2(2400.0, 0.1, -20.0,-4.0, 1E-10, 2000.0)
overShootLimit , exitflag_os = vehicle1.findOverShootLimitD2(2400.0, 0.1, -20.0,-4.0, 1E-10, 2000.0)
print("Overshoot limit : "+str('{:.4f}'.format(overShootLimit))+ " deg")
print("Undershoot limit : "+str('{:.4f}'.format(underShootLimit))+ " deg")
print("TCW: "+ str('{:.4f}'.format(overShootLimit-underShootLimit))+ " deg")
Overshoot limit : -5.1706 deg
Undershoot limit : -5.5815 deg
TCW: 0.4109 deg
[9]:
planet.density_int = density_int_avg
# Set up a vehicle object
vehicle1=Vehicle('SmallSat1', 37, 20, 0.0, 1.767, 0.0, 0.35, planet)
vehicle1.setInitialState(150.0,-6.22,23.16,10.8191,89.9982,-5.00,0.0,0.0)
vehicle1.setSolverParams(1E-6)
vehicle1.setDragModulationVehicleParams(20, 7.5)
underShootLimit, exitflag_us = vehicle1.findUnderShootLimitD2(2400.0, 0.1, -20.0,-4.0, 1E-10, 2000.0)
overShootLimit , exitflag_os = vehicle1.findOverShootLimitD2(2400.0, 0.1, -20.0,-4.0, 1E-10, 2000.0)
print("Overshoot limit : "+str('{:.4f}'.format(overShootLimit))+ " deg")
print("Undershoot limit : "+str('{:.4f}'.format(underShootLimit))+ " deg")
print("TCW: "+ str('{:.4f}'.format(overShootLimit-underShootLimit))+ " deg")
Overshoot limit : -5.1087 deg
Undershoot limit : -5.5295 deg
TCW: 0.4208 deg
[14]:
planet.density_int = density_int_hig
# Set up a vehicle object
vehicle1=Vehicle('SmallSat1', 37, 20, 0.0, 1.767, 0.0, 0.35, planet)
vehicle1.setInitialState(150.0,-6.22,23.16,10.8191,89.9982,-5.00,0.0,0.0)
vehicle1.setSolverParams(1E-6)
vehicle1.setDragModulationVehicleParams(20, 7.5)
underShootLimit, exitflag_us = vehicle1.findUnderShootLimitD2(2400.0, 0.1, -20.0,-4.0, 1E-10, 2000.0)
overShootLimit , exitflag_os = vehicle1.findOverShootLimitD2(2400.0, 0.1, -20.0,-4.0, 1E-10, 2000.0)
print("Overshoot limit : "+str('{:.4f}'.format(overShootLimit))+ " deg")
print("Undershoot limit : "+str('{:.4f}'.format(underShootLimit))+ " deg")
print("TCW: "+ str('{:.4f}'.format(overShootLimit-underShootLimit))+ " deg")
Overshoot limit : -5.0570 deg
Undershoot limit : -5.4834 deg
TCW: 0.4265 deg
Target EFPA selection
[44]:
from matplotlib.patches import Polygon
fig = plt.figure()
fig.set_size_inches([6.25,3.25])
plt.rc('font',family='Times New Roman')
params = {'mathtext.default': 'regular' }
plt.rcParams.update(params)
ax = plt.gca()
x1 = [1.0, 1.0, 2.0, 2.0]
y1 = [-5.5815, -5.1706 , -5.1706, -5.5815]
x2 = [2.0, 2.0, 3.0, 3.0]
y2 = [-5.5295 , -5.1087 , -5.1087 , -5.5295 ]
x3 = [3.0, 3.0, 4.0, 4.0]
y3 = [-5.4834 , -5.0570 , -5.0570 , -5.4834 ]
poly1 = Polygon( list(zip(x1,y1)), facecolor='xkcd:blue', edgecolor='k')
ax.add_patch(poly1)
poly2 = Polygon( list(zip(x2,y2)), facecolor='xkcd:green', edgecolor='k')
ax.add_patch(poly2)
poly3 = Polygon( list(zip(x3,y3)), facecolor='xkcd:red', edgecolor='k')
ax.add_patch(poly3)
plt.ylabel("Entry flight-path angle, deg",fontsize=12)
plt.xlabel("Atmospheric density",fontsize=12)
plt.tick_params(axis='x', # changes apply to the x-axis
which='both', # both major and minor ticks are affected
bottom=False, # ticks along the bottom edge are off
top=False, # ticks along the top edge are off
labelbottom=False)
plt.axhline(y=-5.1706, linewidth=2.0, linestyle='solid' ,color='xkcd:blue')
plt.axhline(y=-5.4834, linewidth=2.0, linestyle='solid' ,color='xkcd:red')
plt.axhline(y=-5.20, linewidth=2.0, linestyle='dashdot' ,color='xkcd:black')
plt.axhline(y=-5.10, linewidth=2.0, linestyle='dotted' ,color='xkcd:black')
plt.axhline(y=-5.30, linewidth=2.0, linestyle='dotted' ,color='xkcd:black')
ax.tick_params(direction='in')
ax.yaxis.set_ticks_position('both')
plt.yticks(fontsize=12)
ax=plt.gca()
ax.xaxis.set_tick_params(direction='in', which='both')
ax.yaxis.set_tick_params(direction='in', which='both')
ax.xaxis.set_tick_params(width=1, length=4)
ax.yaxis.set_tick_params(width=1, length=4)
ax.xaxis.set_tick_params(width=1, length=4, which='minor')
ax.yaxis.set_tick_params(width=1, length=4, which='minor')
ax.xaxis.grid(which='major', color='k', linestyle='dotted', linewidth=0.5)
ax.xaxis.grid(which='minor', color='k', linestyle='dotted', linewidth=0.0)
ax.yaxis.grid(which='major', color='k', linestyle='dotted', linewidth=0.5)
ax.yaxis.grid(which='minor', color='k', linestyle='dotted', linewidth=0.0)
for axis in ['top', 'bottom', 'left', 'right']:
ax.spines[axis].set_linewidth(2)
plt.annotate("Overshoot limit for min. density atmosphere", xy=(0.20, -5.1706), xytext=(1.3, -4.9),
va="center", ha="center",
arrowprops=dict(arrowstyle='->, head_width=0.2', facecolor='blue'), fontsize=10, color='k',
bbox=dict(boxstyle='round,pad=0.2', fc='w', ec='k', alpha=1))
plt.annotate("Undershoot limit for max. density atmosphere" , xy=(0.20, -5.4834),
xytext=(1.3, -5.8),
va="center", ha="center",
arrowprops=dict(arrowstyle='->, head_width=0.2', facecolor='blue'), fontsize=10,color='k',
bbox=dict(boxstyle='round,pad=0.2', fc='w', ec='k', alpha=1))
plt.annotate("Target EFPA" , xy=(4.5, -5.19),
xytext=(4.5, -5.8),
va="center", ha="center",
arrowprops=dict(arrowstyle='->, head_width=0.4', facecolor='blue'), fontsize=10,color='k',
bbox=dict(boxstyle='round,pad=0.2', fc='w', ec='k', alpha=1))
plt.annotate("Assumed delivery error\n" +r"$\pm 0.10$"+ " deg. "+ r"$3\sigma$" , xy=(5.3, -5.32),
xytext=(5.3, -4.97),
va="center", ha="center",
arrowprops=dict(arrowstyle='<->, head_width=0.4', facecolor='blue'), fontsize=10,color='k',
bbox=dict(boxstyle='round,pad=0.2', fc='w', ec='k', alpha=1))
ax.set_xlim([-1.5, 6.5])
ax.set_ylim([-6, -4.7])
plt.text(1.3, -5.70, 'Min', color='xkcd:blue', fontsize=10)
plt.text(2.3, -5.65, 'Avg', color='xkcd:green', fontsize=10)
plt.text(3.3, -5.60, 'Max', color='xkcd:red', fontsize=10)
plt.savefig('../../../data/mdpi-aerospace/smallsat-mission-concepts/venus/venus-ac-efpa-selection.png', dpi= 300,bbox_inches='tight')
plt.savefig('../../../data/mdpi-aerospace/smallsat-mission-concepts/venus/venus-ac-efpa-selection.pdf', dpi=300,bbox_inches='tight')
plt.savefig('../../../data/mdpi-aerospace/smallsat-mission-concepts/venus/venus-ac-efpa-selection.eps', dpi=300,bbox_inches='tight')
plt.show()
