from input.natural_constants import *

# BALLOON DATA
m_pl = 917  #2174       # payload mass in [kg] (incl. flight-chain)
m_bal_init = 540  #500  # initial ballast mass in [kg]
m_film = 0.74074232733 * 1838     # mass balloon film in [kg]
FreeLift = 10     # (initial) free lift in [%]

c_virt = 0.37

# SIMULATION

start_height = 384.9                       # start altitude in [m]
start_lat = 67.887382                      # start latitude in [deg]
start_lon = 21.081452                      # start longitude in [deg]
start_utc_old = '2016-07-12 03:17:24.000'  # start date and time in UTC
start_utc = '2019-06-19 03:17:24.000'      # start date and time in UTC
# possible start dates: between May 22 and June 22
simple = True

# ONLY IN CASE OF APPLICATION OF SIMPLE MODEL:
epsilon_ground = 0.95  # ground emissivity
T_ground = 288.15      # ground temperature
Albedo = 0.3           # total albedo
##cc = 0.1               # cloud cover

m_gas_init = ((m_pl + m_film + m_bal_init) * (FreeLift/100 + 1))/(R_gas/R_air - 1)  # lifting gas mass in [kg]

print("initial gas mass:")
print(m_gas_init)

#GROSSER BALLON
#V_design = 1120497.6  # maximum fillable balloon volume in [m^3]
#L_goreDesign = 1.914 * V_design ** (1/3)
#c_ducts = 0.62
#c_valve = 0.77   # estimated
#A_ducts = 76.54  # estimated
#A_valve = 0.140
#t_open = 20                 # time it takes to open vents in [s]
#t_close = 20                # time it takes to open vents in [s]
#m_baldot = m_bal_init/1375  # ballast mass drop rate in [kg/s]

# kleiner Ballon
V_design = 834497.469  # maximum fillable balloon volume in [m^3]
L_goreDesign = 1.914 * V_design ** (1/3)
c_ducts = 0.62
c_valve = 0.72   # estimated
A_ducts = 55.743  # estimated
A_valve = 0.1297
t_open = 20                 # time it takes to open vents in [s]
t_close = 20                # time it takes to open vents in [s]
m_baldot = m_bal_init/1375  # ballast mass drop rate in [kg/s]


# THERMO-OPTICAL
alpha_VIS = 0.024
r_VIS = 0.060
tau_VIS = 0.916
epsilon = 0.100
alpha_IR = 0.100
tau_IR = 0.860
r_IR = 0.040

c_f = 2092  # [J/(kg*K)] specific heat balloon film


# DRAG
# c_d = 0.47  # drag coefficient balloon (spherical) [-]