def find_fuse_u_coordinate(x_target, fuse_id, fuel_tank_tag):
"""Determines the u coordinate of an OpenVSP fuselage that matches an x coordinate
Assumptions:
Fuselage is aligned with the x axis
Source:
N/A
Inputs:
x_target [m]
fuse_id <str>
fuel_tank_tag <str>
Outputs:
u_current [-] u coordinate for the requests x position
Properties Used:
N/A
"""
tol = 1e-3
diff = 1000
u_min = 0
u_max = 1
while np.abs(diff) > tol:
u_current = (u_max + u_min) / 2
probe_id = vsp.AddProbe(fuse_id, 0, u_current, 0,
fuel_tank_tag + '_probe')
vsp.Update()
x_id = vsp.FindParm(probe_id, 'X', 'Measure')
x_pos = vsp.GetParmVal(x_id)
diff = x_target - x_pos
if diff > 0:
u_min = u_current
else:
u_max = u_current
vsp.DelProbe(probe_id)
return u_current
def write_fuselage_conformal_fuel_tank(fuse_id,fuel_tank,fuel_tank_set_ind):
"""This writes a conformal fuel tank in a fuselage.
Assumptions:
Fuselage is aligned with the x axis
Source:
N/A
Inputs:
fuse_id <str>
fuel_tank.
inward_offset [m]
start_length_percent [-] .1 is 10%
end_length_percent [-]
fuel_type.density [kg/m^3]
fuel_tank_set_ind <int>
Outputs:
Operates on the active OpenVSP model, no direct output
Properties Used:
N/A
"""
#stdout = vsp.cvar.cstdout
#errorMgr = vsp.ErrorMgrSingleton_getInstance()
#errorMgr.PopErrorAndPrint(stdout)
# Unpack
try:
offset = fuel_tank.inward_offset
len_trim_max = fuel_tank.end_length_percent
len_trim_min = fuel_tank.start_length_percent
density = fuel_tank.fuel_type.density
except:
print('Fuel tank does not contain parameters needed for OpenVSP geometry. Tag: '+fuel_tank.tag)
return
tank_id = vsp.AddGeom('CONFORMAL',fuse_id)
vsp.SetGeomName(tank_id, fuel_tank.tag)
# Search for proper x position
# Get min x
probe_id = vsp.AddProbe(fuse_id,0,0,0,fuel_tank.tag+'_probe')
vsp.Update()
x_id = vsp.FindParm(probe_id,'X','Measure')
x_pos = vsp.GetParmVal(x_id)
fuse_x_min = x_pos
vsp.DelProbe(probe_id)
# Get min x
probe_id = vsp.AddProbe(fuse_id,0,1,0,fuel_tank.tag+'_probe')
vsp.Update()
x_id = vsp.FindParm(probe_id,'X','Measure')
x_pos = vsp.GetParmVal(x_id)
fuse_x_max = x_pos
vsp.DelProbe(probe_id)
# Search for u values
x_target_start = (fuse_x_max-fuse_x_min)*fuel_tank.start_length_percent
x_target_end = (fuse_x_max-fuse_x_min)*fuel_tank.end_length_percent
u_start = find_fuse_u_coordinate(x_target_start, fuse_id, fuel_tank.tag)
u_end = find_fuse_u_coordinate(x_target_end, fuse_id, fuel_tank.tag)
# Offset
vsp.SetParmVal(tank_id,'Offset','Design',offset)
# Fuel tank length bounds
vsp.SetParmVal(tank_id,'UTrimFlag','Design',1.)
vsp.SetParmVal(tank_id,'UTrimMax','Design',u_end)
vsp.SetParmVal(tank_id,'UTrimMin','Design',u_start)
# Set density
vsp.SetParmVal(tank_id,'Density','Mass_Props',density)
# Add to the full fuel tank set
vsp.SetSetFlag(tank_id, fuel_tank_set_ind, True)
return