# RCAIDE/Library/Components/Powertrain/Energy/Sources/Fuel_Tanks/Non_Integral_Tank.py
#
#
# Created: September 2024, A. Molloy and M. Clarke
# Modified: Aug 2025, S. Shekar
# ----------------------------------------------------------------------------------------------------------------------
# IMPORT
# ----------------------------------------------------------------------------------------------------------------------
# RCAIDE imports
import RCAIDE
from .Fuel_Tank import Fuel_Tank
from RCAIDE.Library.Methods.Powertrain.Sources.Fuel_Tanks.append_fuel_tank_conditions import append_fuel_tank_conditions
from RCAIDE.Library.Methods.Powertrain.Sources.Fuel_Tanks.Non_Integral_Tank.compute_wing_non_integral_tank_volume import compute_wing_non_integral_tank_volume
from RCAIDE.Library.Methods.Powertrain.Sources.Fuel_Tanks.Non_Integral_Tank.compute_prismatic_tank_volume import compute_prismatic_tank_volume
from RCAIDE.Library.Methods.Powertrain.Sources.Fuel_Tanks.Non_Integral_Tank.compute_rounded_end_cylindrical_tank_volume import compute_rounded_end_cylindrical_tank_volume
from RCAIDE.Library.Methods.Powertrain.Sources.Fuel_Tanks.Non_Integral_Tank.compute_wing_transverse_non_integral_tank_volume import compute_wing_transverse_non_integral_tank_volume
from RCAIDE.Library.Methods.Mass_Properties.Moment_of_Inertia import compute_rounded_end_cylinder_moment_of_inertia, compute_cuboid_moment_of_inertia
from RCAIDE.Library.Methods.Mass_Properties.Center_of_Gravity import compute_cuboid_center_of_gravity, compute_cylinder_center_of_gravity
# ----------------------------------------------------------------------------------------------------------------------
# Fuel Tank
# ---------------------------------------------------------------------------------------------------------------------
[docs]
class Non_Integral_Tank(Fuel_Tank):
"""
Class for modeling non-integral fuel tank characteristics and behavior.
Non-integral tanks are separate fuel storage containers that are not structurally
integrated into the wing or fuselage. They can be attached to wings, fuselages,
or configured as specialized tanks for blended wing body (BWB) aircraft.
Attributes
----------
tag : str
Identifier for the fuel tank (default: 'non_integral_tank')
orientation_euler_angles : list
Euler angles defining tank orientation [rad] (default: [0., 0., 0.])
transverse_tank : bool
Flag indicating if tank is configured as BWB aft tank (default: False)
aft_tank_start_root_chord : float, optional
Starting position of aft tank along root chord [m] (default: None)
aft_tank_end_rood_chord : float, optional
Ending position of aft tank along root chord [m] (default: None)
aft_tank_end_segment_tag : str, optional
Tag of wing segment where aft tank ends (default: None)
wing_root_tag : str, optional
Tag of the root wing for BWB configurations (default: None)
radial_offset : float
Radial offset from attachment surface [m] (default: 0.0)
wing_tag : str, optional
Tag of the wing this tank is attached to (default: None)
fuselage_tag : str, optional
Tag of the fuselage this tank is attached to (default: None)
length : float
Tank length [m] (default: 0.0)
width : float
Tank width [m] (default: 0.0)
height : float
Tank height [m] (default: 0.0)
fuel : Component, optional
Fuel type stored in tank (default: None)
radial_offset : float
Reduction in radius for a tank (default: None)
Notes
-----
Non-integral tanks provide flexibility in fuel storage placement and can be
positioned to optimize aircraft balance and structural efficiency. They are
commonly used in aircraft where integral wing tanks are not feasible or
additional fuel capacity is required.
**Definitions**
'Non-integral Tank'
A fuel storage container that is separate from the primary aircraft structure
and attached externally to wings, fuselages, or other components.
'BWB Aft Tank'
A specialized non-integral tank configuration for blended wing body aircraft
positioned in the aft section of the wing root.
See Also
--------
RCAIDE.Library.Components.Powertrain.Sources.Fuel_Tanks.Fuel_Tank
Base fuel tank class
RCAIDE.Library.Components.Powertrain.Sources.Fuel_Tanks.Integral_Tank
Integral fuel tank class
"""
def __defaults__(self):
"""
Sets default values for central fuel tank attributes
"""
self.tag = 'non_integral_tank'
self.orientation_euler_angles = [0.,0.,0.]
self.geometry_type = 'cylindrical' # ['prismatic', 'cylindrical']
self.transverse_tank_segment_bound = None # This only has one bound since it is more of a end bound and it will always start from the rootchord and grow symmetrically till bound
self.radial_offset = None
self.aspect_ratio = None # Defined as the ratio of total length of the tank to the diameter of the tank. or for a conformal tank it is defined as the ratio of length to height
[docs]
def __init__ (self, compoment=None):
"""
Initialize
"""
if compoment is not None:
if isinstance(compoment, RCAIDE.Library.Components.Wings.Wing):
self.wing_tag = compoment.tag
if isinstance(compoment, RCAIDE.Library.Components.Fuselages.Fuselage):
self.fuselage_tag = compoment.tag
[docs]
def append_operating_conditions(self,segment,fuel_line):
"""
Append fuel tank operating conditions for a flight segment
Parameters
----------
segment : Segment
Flight segment containing state conditions
fuel_line : Component
Connected fuel line component
"""
append_fuel_tank_conditions(self,segment, fuel_line)
return
[docs]
def compute_volume(self, wings, fuselages,fuel_tanks):
"""
Compute the volume of the non-integral fuel tank based on its attachment location.
Parameters
----------
wings : dict
Dictionary containing wing components indexed by their tags
fuselages : dict
Dictionary containing fuselage components indexed by their tags
Returns
-------
volume : float
Computed volume of the fuel tank [m³]
Notes
-----
The volume computation method depends on where the tank is attached:
- If attached to a wing, uses wing geometry and tank dimensions
- If attached to a fuselage, uses fuselage geometry and tank dimensions
- If configured as a BWB aft tank, uses special BWB-specific computation
**Major Assumptions**
* Tank dimensions (length, width, height) are properly defined
* Wing or fuselage components exist in the provided dictionaries
* For BWB aft tanks, the wing_root_tag is properly set
See Also
--------
RCAIDE.Library.Methods.Powertrain.Sources.Fuel_Tanks.Non_Integral_Tank.compute_non_integral_tank_volume
"""
if self.wing_tag is not None and self.transverse_tank is False:
if self.geometry_type == 'cylindrical':
wing = wings[self.wing_tag]
compute_wing_non_integral_tank_volume(self,wing,fuel_tanks)
elif self.transverse_tank is True:
if self.transverse_tank == True:
wing = wings[self.wing_tag]
compute_wing_transverse_non_integral_tank_volume(self,wing,fuel_tanks)
else:
if self.geometry_type == 'prismatic':
compute_prismatic_tank_volume(self)
if self.geometry_type == 'cylindrical':
compute_rounded_end_cylindrical_tank_volume(self)
return
[docs]
def compute_moments_of_inertia(self,vehicle,center_of_gravity=[[0, 0, 0]]):
"""
Computes the moment of inertia tensor for a fuel tank.
Parameters
----------
center_of_gravity : list, optional
Reference point coordinates for moment calculation, defaults to [[0, 0, 0]]
Returns
-------
I : ndarray
3x3 moment of inertia tensor in kg*m^2
"""
if self.geometry_type == 'prismatic':
_, _ = compute_cuboid_moment_of_inertia(self,
outer_length=self.lengths.external,
outer_width=self.widths.external,
outer_height=self.heights.external,\
inner_length=self.lengths.external- 2*self.wall_thickness,
inner_width=self.widths.external- 2*self.wall_thickness,
inner_height=self.heights.external- 2*self.wall_thickness,
center_of_gravity=center_of_gravity,
fuel_tank=True)
else:
_, _ = compute_rounded_end_cylinder_moment_of_inertia(self,
outer_length=self.lengths.external,
outer_radius=self.diameters.external/2,
inner_length=self.lengths.external - 2*self.wall_thickness,
inner_radius=self.diameters.external/2 - self.wall_thickness,
center_of_gravity=center_of_gravity,
fuel_tank = True)
return
[docs]
def compute_center_of_gravity(self,vehicle):
"""
Computes the center of gravity for a fuel tank.
Parameters
----------
center_of_gravity : list, optional
Reference point coordinates for moment calculation, defaults to [[0, 0, 0]]
Returns
-------
I : ndarray
3x3 moment of inertia tensor in kg*m^2
"""
if self.geometry_type == 'prismatic':
_ = compute_cuboid_center_of_gravity(self,length=self.lengths.external)
else:
length = self.lengths.external + self.diameters.external
_ = compute_cylinder_center_of_gravity(self, length )
return
