changed basic thermal model, now realistic behavior

This commit is contained in:
Marcel Christian Frommelt 2021-01-25 20:25:41 +09:00
parent e011c90ad0
commit d0d56c1fc9
10 changed files with 418 additions and 39 deletions

52
DataRequest.py Normal file
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@ -0,0 +1,52 @@
import cdsapi
c = cdsapi.Client()
r = c.retrieve(
'reanalysis-era5-pressure-levels',
{
'product_type': 'reanalysis',
'variable': [
'fraction_of_cloud_cover', 'geopotential', 'relative_humidity',
'specific_humidity', 'temperature', 'u_component_of_wind',
'v_component_of_wind', 'vertical_velocity',
],
'pressure_level': [
'1', '2', '3',
'5', '7', '10',
'20', '30', '50',
'70', '100', '125',
'150', '175', '200',
'225', '250', '300',
'350', '400', '450',
'500', '550', '600',
'650', '700', '750',
'775', '800', '825',
'850', '875', '900',
'925', '950', '975',
'1000',
],
'year': '2016',
'month': '07',
'day': [
'11', '12', '13',
'14', '15', '16',
'17', '18',
],
'time': [
'00:00', '01:00', '02:00',
'03:00', '04:00', '05:00',
'06:00', '07:00', '08:00',
'09:00', '10:00', '11:00',
'12:00', '13:00', '14:00',
'15:00', '16:00', '17:00',
'18:00', '19:00', '20:00',
'21:00', '22:00', '23:00',
],
'area': [
72, -111, 67,
22,
],
'format': 'netcdf',
})
r.download('test.nc')

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@ -1,3 +0,0 @@
# BASTET
ESBO Balloon Simulation and Trajectory Evaluation Tool

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input/Trial_2021-01-12.py Normal file
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@ -0,0 +1,174 @@
import numpy as np
from astropy.time import Time
# SIMPLE ATMOSPHERE MODEL
def T_air(h):
if h >= 0 and h <= 11000:
res = 288.15 - 0.0065 * h
return res
elif h > 11000 and h <= 20000:
res = 216.65
return res
elif h >= 20000:
res = 216.65 + 0.0010 * (h - 20000)
return res
def p_air(h):
if h >= 0 and h <= 11000:
res = 101325 * ((288.15 - 0.0065 * h)/288.15) ** 5.25577
return res
elif h > 11000 and h <= 20000:
res = 22632 * np.exp(-(h - 11000)/6341.62)
return res
elif h > 20000:
res = 5474.87 * ((216.65 + 0.0010 * (h - 20000))/216.65) ** (-34.163)
return res
def rho_air(h):
res = p_air(h)/(R_air * T_air(h))
return res
# USER INPUT
start_height = 0
start_utc = '2006-01-16 08:00:00.000'
start_lat = 0 # start latitude in [deg]
start_lon = 0 # start longitude in [deg]
# INITIALISATION
t = 0
h = start_height
lat = start_lat
lon = start_lon
utc = Time(start_utc)
v_z = 0
p_gas = p_air(h)
T_gas = T_air(h)
T_film = T_gas
p_0 = 101325
dT_gas = (Q_ConvInt / (gamma * m_gas * c_v) - (gamma - 1) / gamma * rho_air(h) * g / (rho_gas * R_gas) * RoC) * dt
dT_film = ((Q_Sun + Q_Albedo + Q_IREarth + Q_IRfilm + Q_ConvExt - Q_ConvInt - Q_IRout) / (c_f * m_film)) * dt
dT_gas = (Q_g/(c_pg * m_g) - (g * M_a * m_g * T_g)/(c_pg * T_a * M_g) * dz/dt) * dt
V_b_new = m_gas * R_gas * T_gas_new/p_gas_new # r.h.s. with updated values!
v_w = 0
T_g1 = T_g
T_a1 = T_a
# Q_g1 = ???
T_e1 = T_e
# T_g2 = T_g1 + dt * (Q_g1/(c_pg * m_g1) - g * M_a * T_g1 * dh/(c_pg * T_a1 * M_g))
# T_e2 = T_e1 + Q_e/(c_env * m_e) * dt
T_gn = T_g + dt * (Q_g/(c_pg * m_g) - g * M_a * T_g * dh/(c_pg * T_a * M_g))
T_en = T_e + Q_e/(c_env * m_e) * dt
s_n = s + dt * v + 0.5 * a * dt ** 2
v_n = v - v_w + dt * a
T_g = T_gn
T_e = T_en
s = s_n
v = v_n
V = m_g * R_g * T_g / (p_g)
dV_b = V_b_new - V_b # calculating volume increment
dT_gas = Q_ConvInt/(c_v * m_g) * dt + (gamma - 1) * T_g * (dm_g/m_g - dV_b/V_b)
V_b = V_b_new # updating current volume
dT_film = ((Q_Sun + Q_Albedo + Q_IREarth + Q_IRfilm + Q_ConvExt - Q_ConvInt - Q_IRout) / (c_f * m_film)) * dt
m_balloon = A_balloon * rho_envelope
m_gas = Vol_balloon * (M_gas * p_gas)/(R_c * T_gas)
m_gross = m_balloon + m_payload
m_tot = m_balloon + m_gas + m_payload
GI = F_buoyant - g * (rho_a - rho_g) * Vol_balloon
W = m_gross * g
m_virtual = m_tot + C_virtual * rho_a * Vol_balloon
R_z = GI + T_z - D_z - W
dV_A = (R_z * dt)/m_virtual
F_Drag = 0.5 * C_D * rho * np.abs(V) * V * A_cross
Re = (rho * V * l)/my
C_D = 24/Re
my = my_0 * (T_0 + C)/(T + C) * (T/T_0) ** (3/2)
C_D = 0.23175 - 0.15757 * f + 0.04744 * f ** 2 - 7.0412 * 10 ** (-3) * f ** 3 + 5.1534 * 10 ** (-4) * f ** 4 - 1.4835 * 10 ** (-5) * f ** 5
Vol_balloon = m_g * R_g * T_g/p_g
Vol_ballon_new = m_g * R_g * T_g/p_g # r.h.s. with updated values!
dVol = Vol_ballon_new - Vol_balloon # calculating volume increment
Vol_ballon = Vol_ballon_new # updating current volume
L_z = g * (M_atm * p_atm/(R * T_atm) - M_gas * p_gas/(R * T_gas)) * Vol_balloon
dT_g = Q_ConvInt/(c_v * m_g) * dt + (gamma - 1) * T_g * (dm_g/m_g - dVol/Vol)
dT_e = (Q_sun + Q_albedo + Q_IREarth + Q_IRsky + Q_ConvExt - Q_ConvInt + Q_IRout)/(c_e * m_e)
Pr_g = my_g * c_pg/kappa_g
Pr_a = my_a * c_pa/kappa_a
beta_g = 1/T_g
beta_a = 1/T_a
Gr_g = d_b ** 3 * rho_g ** 2 * g * beta_g * (T_e - T_g)/(my_g ** 2)
Gr_a = d_b ** 3 * rho_a ** 2 * g * beta_a * (T_e - T_a)/(my_a ** 2)
h = h + dt * V + 0.5 * a * dt ** 2
V = V + dt * a

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@ -1,7 +1,8 @@
g = 9.81 # local gravitational acceleration in [m/s^2]
c_v = 3115.89 # [J/(kg * K)]
R_air = 287.1 # Specific Gas Constant Dry Air in [J/(kg * K)]
R_gas = 2077.1 # Specific Gas Constant Helium in [J/(kg * K)]
R_E = 6378000 # Earth Radius in [m]
e = 0.016708 # Eccentricity of Earth's Orbit
sigma = 5.670374419 * 10 ** -8 # Stefan-Boltzmann-Constant
gamma = 1.4
gamma = 1.667 # 1.44 # 1.6

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@ -1,8 +1,9 @@
# BALLOON
m_pl = 10.0 # payload mass in [kg]
m_film = 1.0 # mass balloon film in [kg]
m_gas = 1.7645 # 1.60391061452 # lifting gas mass in [kg]
V_max = 9999999 # maximum fillable balloon volume in [m^3]
m_pl = 417.57 # payload mass in [kg]
m_film = 7.74 # mass balloon film in [kg]
m_gas = 5 * 74.98539754298822 # 1.60391061452 # lifting gas mass in [kg]
V_design = 334705 # maximum fillable balloon volume in [m^3]
L_goreDesign = 1.914 * V_design ** (1/3)
# THERMO-OPTICAL
alpha_VIS = 0.024
@ -16,19 +17,19 @@ r_IR = 0.04
c_f = 2092 # [J/(kg*K)]
epsilon_ground = 0.9
Albedo = 0.2
Albedo = 0.1
T_ground = 273.15
# DRAG
c_d = 0.47 # drag coefficient balloon (spherical) [-]
c_virt = 0
c_virt = 0.37
# SIMULATION
t_end = 10000 # maximum simulation time in [s]
dt = 0.1 # simulation time step in [s]
start_height = 0.0 # start altitude in [m]
start_lat = 0.0 # start latitude in [deg]
start_lon = 0.0 # start longitude in [deg]
start_utc = '2020-12-13 12:00:00.000' # start date and time in UTC
p_0 = 1013.25 # sea-level pressure
t_end = 10000 #5000 # maximum simulation time in [s]
dt = 0.01 #0.01 # simulation time step in [s]
start_height = 0.0 # start altitude in [m]
start_lat = 39.9161 # start latitude in [deg]
start_lon = 9.6889 # start longitude in [deg]
start_utc = '2006-01-16 08:00:00.000' # start date and time in UTC
p_0 = 101325 # sea-level pressure

52
main.py
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@ -20,9 +20,6 @@ lon = start_lon # deg
date = Time('2020-12-13 12:00:00.000')
AZ = sun_angles_astropy(45.0, 45.0, 0, date)[0]
ELV = sun_angles_astropy(45.0, 45.0, 0, date)[1]
# INITIALISATION
@ -45,9 +42,9 @@ while t <= t_end and h >= 0:
V_b = m_gas/rho_gas # calculate balloon volume from current gas mass and gas density
if V_b > V_max:
V_b = V_max
m_gas = V_max * rho_gas
if V_b > V_design:
V_b = V_design
m_gas = V_design * rho_gas
else:
pass
@ -55,7 +52,12 @@ while t <= t_end and h >= 0:
m_tot = m_pl + m_film + m_gas
m_virt = m_tot + c_virt * rho_air(h) * V_b
d_b = (6.0 * V_b / np.pi) ** (1/3) # calculate diameter of balloon from its volume
d_b = 1.383 * V_b ** (1/3) # calculate diameter of balloon from its volume
L_goreB = 1.914 * V_b ** (1/3)
h_b = 0.748 * d_b
A_surf = 4.94 * V_b ** (2/3)
A_surf1 = 4.94 * V_design ** (2/3) * (1 - np.cos(np.pi * L_goreB/L_goreDesign))
A_eff = 0.65 * A_surf + 0.35 * A_surf1
A_top = np.pi/4 * d_b ** 2
D = drag(c_d, rho_air(h), d_b, v_z) # calculate drag force
@ -68,12 +70,6 @@ while t <= t_end and h >= 0:
AZ, ELV = sun_angles_analytical(lat, lon, utc)
A_proj = A_top * (0.9125 + 0.0875 * np.cos(np.pi - 2 * np.deg2rad(ELV)))
A_surf = 4.94 * V_b ** (2/3)
A_eff = A_surf
#A_surf1 = 4.94 * V_b
# AirMass(x, p_0, ELV, h)
# CALCULATIONS FOR THERMAL MODEL
@ -129,19 +125,31 @@ while t <= t_end and h >= 0:
RoC = -v_z
dT_gas = (Q_ConvInt / (gamma * R_gas) - (gamma - 1) / gamma * rho_air(h) * g / (rho_gas * R_gas) * RoC) * dt
dT_film = ((Q_Sun + Q_Albedo + Q_IREarth + Q_IRfilm + Q_ConvExt - Q_ConvInt - Q_IRout) / (c_f * m_film)) * dt
# dT_gas = (Q_ConvInt / (gamma * m_gas * c_v) - (gamma - 1) / gamma * rho_air(h) * g / (rho_gas * R_gas) * RoC) * dt
# dT_film = ((Q_Sun + Q_Albedo + Q_IREarth + Q_IRfilm + Q_ConvExt - Q_ConvInt - Q_IRout) / (c_f * m_film)) * dt
###
v_w = 0
v = v_z
s = h
dv_z = F/m_virt * dt # velocity increment
a = F/m_virt
v_z += dv_z * dt # velocity differential
h += v_z * dt # altitude differential
s_n = s + dt * v + 0.5 * a * dt ** 2
dh = s_n - s
v_n = v - v_w + dt * a
p_gas = p_air(h)
T_gas = T_gas + dT_gas * dt
T_film = T_film + dT_film * dt
T_gn = T_gas + dt * (Q_ConvInt / (gamma * c_v * m_gas) - g * R_gas * T_gas * dh / (c_v * gamma * T_air(s) * R_air))
T_en = T_film + (Q_Sun + Q_Albedo + Q_IREarth + Q_IRfilm + Q_ConvExt - Q_ConvInt - Q_IRout) / (c_f * m_film) * dt
T_g = T_gn
T_e = T_en
s = s_n
v = v_n
h = s
T_gas = T_g
T_film = T_e
v_z = v
t += dt # time increment
utc = Time(start_utc) + t * u.second

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main_old.py Normal file
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import numpy as np
import matplotlib.pyplot as plt
from datetime import datetime
begin_time = datetime.now()
from models.sun import sun_angles_analytical
from models.sun import sun_angles_astropy
from models.drag import drag, c_d
from models.simple_atmosphere import T_air, p_air, rho_air
from input.user_input import *
from input.natural_constants import *
from astropy.time import Time
import astropy.units as u
from models.thermal import AirMass
# t: simulation time (0 .. t_max) in [s]
# utc = Time(start_utc) + t * u.second # current time (UTC)
lat = start_lat # deg
lon = start_lon # deg
date = Time('2020-12-13 12:00:00.000')
# INITIALISATION
t = 0
h = start_height
utc = Time(start_utc)
v_z = 0
p_gas = p_air(h)
T_gas = T_air(h)
T_film = T_gas
t_list = []
h_list = []
while t <= t_end and h >= 0:
t_list.append(t)
h_list.append(h)
rho_gas = p_gas/(R_gas * T_gas) # calculate gas density through ideal(!) gas equation
V_b = m_gas/rho_gas # calculate balloon volume from current gas mass and gas density
if V_b > V_design:
V_b = V_design
m_gas = V_design * rho_gas
else:
pass
m_gross = m_pl + m_film
m_tot = m_pl + m_film + m_gas
m_virt = m_tot + c_virt * rho_air(h) * V_b
d_b = 1.383 * V_b ** (1/3) # calculate diameter of balloon from its volume
L_goreB = 1.914 * V_b ** (1/3)
h_b = 0.748 * d_b
A_surf = 4.94 * V_b ** (2/3)
A_surf1 = 4.94 * V_design ** (2/3) * (1 - np.cos(np.pi * L_goreB/L_goreDesign))
A_eff = 0.65 * A_surf + 0.35 * A_surf1
A_top = np.pi/4 * d_b ** 2
D = drag(c_d, rho_air(h), d_b, v_z) # calculate drag force
I = g * V_b * (rho_air(h) - rho_gas) # calculate gross inflation
W = g * m_gross # calculate weight (force)
F = I - W - D * np.sign(v_z)
v_zrel = v_z
AZ, ELV = sun_angles_analytical(lat, lon, utc)
A_proj = A_top * (0.9125 + 0.0875 * np.cos(np.pi - 2 * np.deg2rad(ELV)))
# CALCULATIONS FOR THERMAL MODEL
if ELV >= -(180 / np.pi * np.arccos(R_E / (R_E + h))):
tau_atm = 0.5 * (np.exp(-0.65 * AirMass(p_air(h), p_0, ELV, h)) + np.exp(-0.095 * AirMass(p_air(h), p_0, ELV, h)))
tau_atmIR = 1.716 - 0.5 * (np.exp(-0.65 * p_air(h) / p_0) + np.exp(-0.095 * p_air(h) / p_0))
else:
tau_atm = 0
tau_atmIR = 0
doy = int(utc.doy)
MA = (357.52911 + 0.98560028 * (utc.jd - 2451545)) % 360 # in degree, reference: see folder "literature"
TA = MA + 2 * e * np.sin(np.deg2rad(MA)) + 5 / 4 * e ** 2 * np.sin(np.deg2rad(2 * MA))
I_Sun = 1367.5 * ((1 + e * np.cos(np.deg2rad(TA))) / (1 - e ** 2)) ** 2
I_SunZ = I_Sun * tau_atm
q_sun = I_SunZ
q_IRground = epsilon_ground * sigma * T_ground ** 4
q_IREarth = q_IRground * tau_atmIR
if ELV <= 0:
q_Albedo = 0
else:
q_Albedo = Albedo * I_Sun * np.sin(np.deg2rad(ELV))
my_air = (1.458 * 10 ** -6 * T_air(h) ** 1.5) / (T_air(h) + 110.4)
my_gas = 1.895 * 10 ** -5 * (T_gas / 273.15) ** 0.647
k_air = 0.0241 * (T_air(h) / 273.15) ** 0.9
k_gas = 0.144 * (T_gas / 273.15) ** 0.7
Pr_air = 0.804 - 3.25 * 10 ** (-4) * T_air(h)
Pr_gas = 0.729 - 1.6 * 10 ** (-4) * T_gas
Gr_air = (rho_air(h) ** 2 * g * np.abs(T_film - T_air(h)) * d_b ** 3) / (T_air(h) * my_air ** 2)
Nu_air = 2 + 0.45 * (Gr_air * Pr_air) ** 0.25
HC_free = Nu_air * k_air / d_b
Re = np.abs(v_zrel) * d_b * rho_air(h) / my_air
HC_forced = k_air / d_b * (2 + 0.41 * Re ** 0.55)
HC_internal = 0.13 * k_gas * ((rho_gas ** 2 * g * np.abs(T_film - T_gas) * Pr_gas) / (T_gas * my_air ** 2)) ** (
1 / 3)
HC_external = np.maximum(HC_free, HC_forced)
HalfConeAngle = np.arcsin(R_E / (R_E + h))
ViewFactor = (1 - np.cos(HalfConeAngle)) / 2
Q_Sun = alpha_VIS * A_proj * q_sun * (1 + tau_VIS / (1 - r_VIS))
Q_Albedo = alpha_VIS * A_surf * q_Albedo * ViewFactor * (1 + tau_VIS / (1 - r_VIS))
Q_IREarth = alpha_IR * A_surf * q_IREarth * ViewFactor * (1 + tau_IR / (1 - r_IR))
Q_IRfilm = sigma * epsilon * alpha_IR * A_surf * T_film ** 4 * 1 / (1 - r_IR)
Q_IRout = sigma * epsilon * A_surf * T_film ** 4 * (1 * tau_IR / (1 - r_IR))
Q_ConvExt = HC_external * A_eff * (T_air(h) - T_film)
Q_ConvInt = HC_internal * A_eff * (T_film - T_gas)
RoC = -v_z
dT_gas = (Q_ConvInt / (gamma * m_gas * c_v) - (gamma - 1) / gamma * rho_air(h) * g / (rho_gas * R_gas) * RoC) * dt
dT_film = ((Q_Sun + Q_Albedo + Q_IREarth + Q_IRfilm + Q_ConvExt - Q_ConvInt - Q_IRout) / (c_f * m_film)) * dt
###
dv_z = F/m_virt * dt # velocity increment
v_z += dv_z * dt # velocity differential
h += v_z * dt # altitude differential
p_gas = p_air(h)
T_gas = T_gas + dT_gas * dt
T_film = T_film + dT_film * dt
t += dt # time increment
utc = Time(start_utc) + t * u.second
plt.plot(t_list, h_list)
plt.show()