aerosandbox.library.weights.torenbeek_weights#

Module Contents#

Functions#

mass_wing_simple(wing, design_mass_TOGW, ...[, ...])

Computes the mass of a wing of an aircraft, according to Torenbeek's "Synthesis of Subsonic

mass_wing_high_lift_devices(wing, max_airspeed_for_flaps)

The function mass_high_lift() is designed to estimate the weight of the high-lift devices

mass_wing_basic_structure(wing, design_mass_TOGW, ...)

Computes the mass of the basic structure of the wing of an aircraft, according to

mass_wing_spoilers_and_speedbrakes(wing, mass_basic_wing)

The function mass_spoilers_and_speedbrakes() estimates the weight of the spoilers and speedbrakes

mass_wing(wing, design_mass_TOGW, ...[, ...])

Computes the mass of a wing of an aircraft, according to Torenbeek's "Synthesis of Subsonic Airplane Design",

mass_fuselage_simple(fuselage, never_exceed_airspeed, ...)

Computes the mass of the fuselage, using Torenbeek's simple version of the calculation.

mass_fuselage(fuselage, design_mass_TOGW, ...)

mass_propeller(propeller_diameter, propeller_power, ...)

Computes the mass of a propeller.
aerosandbox.library.weights.torenbeek_weights.mass_wing_simple(wing, design_mass_TOGW, ultimate_load_factor, suspended_mass, main_gear_mounted_to_wing=True)[source]#

Computes the mass of a wing of an aircraft, according to Torenbeek’s “Synthesis of Subsonic Airplane Design”.

This is the simple version of the wing weight model, which is found in: Section 8.4: Weight Prediction Data and Methods 8.4.1: Airframe Structure Eq. 8-12

A more detailed version of the wing weight model is available in the mass_wing() function in this same module.

Parameters:

  • wing (aerosandbox.Wing) – The wing object. Should be an AeroSandbox Wing object.

  • design_mass_TOGW (float) – The design takeoff gross weight of the entire aircraft [kg].

  • ultimate_load_factor (float) – The ultimate load factor of the aircraft. 1.5x the limit load factor.

  • suspended_mass (float) – The mass of the aircraft that is suspended from the wing [kg].

  • main_gear_mounted_to_wing (bool) – Whether the main gear is mounted to the wing structure.

Return type:

float

Returns: The total mass of the wing [kg].

aerosandbox.library.weights.torenbeek_weights.mass_wing_high_lift_devices(wing, max_airspeed_for_flaps, flap_deflection_angle=30, k_f1=1.0, k_f2=1.0)[source]#
The function mass_high_lift() is designed to estimate the weight of the high-lift devices

on an airplane wing. It uses Torenbeek’s method, which is based on multiple factors like wing design and flap deflection.

Parameters:

  • wing (aerosandbox.Wing) –

  • class (an instance of AeroSandbox's Wing) –

  • max_airspeed_for_flaps (float) –

  • flap_deflection_angle (float) –

  • k_f1 (float) –

  • k_f2 (float) –

Return type:

float

:param : :param max_airspeed_for_flaps: :param the maximum airspeed at which the flaps can be deployed [m/s]: :param flap_deflection_angle: :param the angle to which the flaps can be deflected [deg]. Default value is 30 degrees.: :param k_f1: = 1.0 for single-slotted; double-slotted, fixed hinge

= 1.15 for double: slotted, 4-bar movement; single-slotted Fowler = 1.3 for double-slotted Fowler = 1.45 for triple-slotted Fowler

Parameters:

  • 1 (configuration factor) – = 1.0 for single-slotted; double-slotted, fixed hinge = 1.15 for double: slotted, 4-bar movement; single-slotted Fowler = 1.3 for double-slotted Fowler = 1.45 for triple-slotted Fowler

  • values (with) – = 1.0 for single-slotted; double-slotted, fixed hinge = 1.15 for double: slotted, 4-bar movement; single-slotted Fowler = 1.3 for double-slotted Fowler = 1.45 for triple-slotted Fowler

  • k_f2 (float) –

    = 1.0 for slotted flaps with fixed vanes = 1.25 for double-slotted flaps with “variable geometry”, i.e., extending

    flaps with separately moving vanes or auxiliary flaps

  • 2 (configuration factor) –

    = 1.0 for slotted flaps with fixed vanes = 1.25 for double-slotted flaps with “variable geometry”, i.e., extending

    flaps with separately moving vanes or auxiliary flaps

  • values –

    = 1.0 for slotted flaps with fixed vanes = 1.25 for double-slotted flaps with “variable geometry”, i.e., extending

    flaps with separately moving vanes or auxiliary flaps

  • wing (aerosandbox.Wing) –

  • max_airspeed_for_flaps (float) –

  • flap_deflection_angle (float) –

  • k_f1 (float) –

Return type:

float

Returns: Mass of the wing’s high-lift system only [kg]

aerosandbox.library.weights.torenbeek_weights.mass_wing_basic_structure(wing, design_mass_TOGW, ultimate_load_factor, suspended_mass, never_exceed_airspeed, main_gear_mounted_to_wing=True, strut_y_location=None, k_e=0.95, return_dict=False)[source]#
Computes the mass of the basic structure of the wing of an aircraft, according to

Torenbeek’s “Synthesis of Subsonic Airplane Design”, 1976, Appendix C: “Prediction of Wing Structural Weight”. This is the basic wing structure without movables like spoilers, high-lift devices, etc.

Likely more accurate than the Raymer wing weight models.

Parameters:

  • wing (aerosandbox.Wing) – The wing object.

  • design_mass_TOGW (float) – The design takeoff gross weight of the entire aircraft [kg].

  • ultimate_load_factor (float) – The ultimate load factor of the aircraft [-]. 1.5x the limit load factor.

  • suspended_mass (float) – The mass of the aircraft that is suspended from the wing [kg]. It should exclude any wing attachments that are not part of the wing structure.

  • never_exceed_airspeed (float) – The never-exceed airspeed of the aircraft [m/s]. Used for flutter calculations.

  • main_gear_mounted_to_wing (bool) – Whether the main gear is mounted to the wing structure. Boolean.

  • strut_y_location (float) – The spanwise-location of the strut (if any), as measured from the wing root [meters]. If None, it is assumed that there is no strut (i.e., the wing is a cantilever beam).

  • k_e (float) –

    represents weight knockdowns due to bending moment relief from engines mounted in front of elastic axis. see Torenbeek unlabeled equations, between C-3 and C-4.

    k_e = 1.0 if engines are not wing mounted, k_e = 0.95 (default) two wing mounted engines in front of the elastic axis and k_e = 0.90 four wing-mounted engines in front of the elastic axis

  • return_dict (bool) – Whether to return a dictionary of all the intermediate values, or just the final mass. Defaults to False, which returns just the final mass [kg].

Return type:

Union[float, Dict[str, float]]

Returns: If return_dict is False (default), returns a single value: the mass of the basic wing [kg]. If return_dict is

True, returns a dictionary of all the intermediate values.

aerosandbox.library.weights.torenbeek_weights.mass_wing_spoilers_and_speedbrakes(wing, mass_basic_wing)[source]#
The function mass_spoilers_and_speedbrakes() estimates the weight of the spoilers and speedbrakes

according to Torenbeek’s “Synthesis of Subsonic Airplane Design”, 1976, Appendix C: “Prediction of Wing Structural Weight”.

N.B. the weight is coming out unrealistic and approx. 20-30% of the weight of the wing. This needs

a correction. It uses normally the 12.2 kg/m^2 wing area.

Parameters:

  • wing (aerosandbox.Wing) – an instance of AeroSandbox’s Wing class.

  • mass_basic_wing (float) – The basic weight of the wing (without spoilers, speedbrakes, flaps, slats) [kg]

Return type:

float

Returns: The mass of the spoilers and speed brakes only [kg]

N.B. the weight estimation using the 12.2 kg/m^2 figure comes out too high if using

the wing as a referenced area. Reduced to 1.5% of the basic wing mass.

aerosandbox.library.weights.torenbeek_weights.mass_wing(wing, design_mass_TOGW, ultimate_load_factor, suspended_mass, never_exceed_airspeed, max_airspeed_for_flaps, main_gear_mounted_to_wing=True, flap_deflection_angle=30, strut_y_location=None, return_dict=False)[source]#
Computes the mass of a wing of an aircraft, according to Torenbeek’s “Synthesis of Subsonic Airplane Design”,

1976, Appendix C: “Prediction of Wing Structural Weight”.

Likely more accurate than the Raymer wing weight models.

Parameters:

  • wing (aerosandbox.Wing) – The wing object.

  • design_mass_TOGW (float) – The design takeoff gross weight of the entire aircraft [kg].

  • ultimate_load_factor (float) – The ultimate load factor of the aircraft. 1.5x the limit load factor.

  • suspended_mass (float) – The mass of the aircraft that is suspended from the wing [kg].

  • never_exceed_airspeed (float) – The never-exceed airspeed of the aircraft [m/s]. Used for flutter calculations.

  • max_airspeed_for_flaps (float) – The maximum airspeed at which the flaps are allowed to be deployed [m/s]. In the

  • information (absence of other) –

  • guess. (1.8x stall speed is a good) –

  • main_gear_mounted_to_wing (bool) – Whether the main gear is mounted to the wing structure.

  • flap_deflection_angle (float) – The maximum deflection angle of the flaps [deg].

  • strut_y_location (float) – The y-location of the strut (if any), relative to the wing’s leading edge [m]. If None, it is assumed that there is no strut (i.e., the wing is a cantilever beam).

  • return_dict (bool) – Whether to return a dictionary of all the intermediate values, or just the final mass. Defaults to False, which returns just the final mass.

Return type:

Union[float, Dict[str, float]]

Returns: If return_dict is False (default), returns a single value: the total mass of the wing [kg]. If

return_dict is True, returns a dictionary of all the intermediate values.

aerosandbox.library.weights.torenbeek_weights.mass_fuselage_simple(fuselage, never_exceed_airspeed, wing_to_tail_distance)[source]#

Computes the mass of the fuselage, using Torenbeek’s simple version of the calculation.

Source: Torenbeek: “Synthesis of Subsonic Airplane Design”, 1976 Section 8.4: Weight Prediction Data and Methods 8.4.1: Airframe Structure Eq. 8-16

Parameters:

  • fuselage (aerosandbox.Fuselage) – The fuselage object. Should be an AeroSandbox Fuselage object.

  • never_exceed_airspeed (float) – The never-exceed airspeed of the aircraft, in m/s.

  • wing_to_tail_distance (float) – The distance from the quarter-chord of the wing to the quarter-chord of the tail,

  • meters. (in) –

Returns: The mass of the fuselage, in kg.

aerosandbox.library.weights.torenbeek_weights.mass_fuselage(fuselage, design_mass_TOGW, ultimate_load_factor, never_exceed_airspeed, wing_to_tail_distance)[source]#
Parameters:

  • fuselage (aerosandbox.Fuselage) –

  • design_mass_TOGW (float) –

  • ultimate_load_factor (float) –

  • never_exceed_airspeed (float) –

  • wing_to_tail_distance (float) –

aerosandbox.library.weights.torenbeek_weights.mass_propeller(propeller_diameter, propeller_power, n_blades)[source]#

Computes the mass of a propeller.

From Torenbeek: “Synthesis of Subsonic Airplane Design”, 1976, Delft University Press. Table 8-9 (pg. 286, PDF page 306)

Parameters:

  • propeller_diameter (float) – Propeller diameter, in meters.

  • propeller_power (float) – Propeller power, in watts.

  • n_blades (int) – Number of propeller blades.

Return type:

float

Returns: Propeller mass, in kilograms.