RCAIDE.Library.Methods.Mass_Properties.Weight_Buildups.Conventional.Transport.Raymer.compute_propulsion_system_weight

compute_propulsion_system_weight#

compute_propulsion_system_weight(vehicle, network)[source]#

Calculates the total propulsion system weight using Raymer’s method, including subsystems.

Parameters:

  • vehicle (RCAIDE.Vehicle()) –

    Vehicle data structure containing:
    • networkslist

      List of propulsion networks

    • fuselageslist

      List of fuselage components

    • flight_envelopeData()

      Contains design_mach_number

    • mass_propertiesData()

      Contains max_zero_fuel

  • network (RCAIDE.Network()) –

    Network component containing:
    • fuel_lineslist

      List of fuel line components with fuel tanks

    • propulsorslist

      List of propulsion components

Returns:

output –

Propulsion system weight breakdown:
  • W_propfloat

    Total propulsion system weight [kg]

  • W_thrust_reverserfloat

    Thrust reverser weight [kg]

  • W_starterfloat

    Starter engine weight [kg]

  • W_engine_controlsfloat

    Engine controls weight [kg]

  • W_fuel_systemfloat

    Fuel system weight [kg]

  • W_nacellefloat

    Nacelle weight [kg]

  • W_enginefloat

    Total dry engine weight [kg]

  • number_of_enginesint

    Number of engines

  • number_of_fuel_tanksint

    Number of fuel tanks

Return type:

Data()

Notes

This method calculates the complete propulsion system weight including engines, nacelles, fuel system, and all supporting systems using Raymer’s correlations.

Major Assumptions

  • Correlations based on conventional turbofan/turbojet installations

  • Engine controls scale with number of engines and fuselage length

  • Nacelle weight includes thrust reversers if applicable

  • Fuel system weight scales with fuel capacity and number of tanks

  • Starter weight scales with total engine weight

Theory Key component weights are calculated using: .. math:

W_{nacelle} = 0.6724K_{ng}L_n^{0.1}W_n^{0.294}N_{ult}^{0.119}W_{ec}^{0.611}N_{eng}^{0.984}S_n^{0.224}
\[W_{fuel\_sys} = 1.07W_{fuel}^{0.58}N_{eng}^{0.43}M_{max}^{0.34}\]
\[W_{engine} = 0.084BPR^{1.1}W_{eng}^{0.5}N_{eng}^{0.5}\]
\[W_{engine\_controls} = 5N_{eng} + 0.8L_{eng}\]
\[W_{starter} = 49.19\left(\]

rac{W_{eng}}{1000} ight)^{0.541}

where:

  • \(K_{ng}\) is a factor for the engine mount type

  • \(L_n\) is the length of the nacelle

  • \(W_n\) is the diameter of the nacelle

  • \(N_{ult}\) is the ultimate load factor

  • \(W_{ec}\) is the engine control weight

  • \(N_{eng}\) is the number of engines

  • \(BPR\) is the bypass ratio

  • \(W_{eng}\) is the dry engine weight

  • \(L_{eng}\) is the length of the engine

  • \(N_{eng}\) is the number of engines

  • \(W_{fuel}\) is the fuel weight

  • \(M_{max}\) is the maximum Mach number

  • \(S_n\) is the nacelle surface area

References

[1] Raymer, D., “Aircraft Design: A Conceptual Approach”, AIAA

Education Series, 2018.

See also

RCAIDE.Library.Methods.Weights.Correlation_Buildups.FLOPS.compute_jet_engine_weight, RCAIDE.Library.Methods.Weights.Correlation_Buildups.FLOPS.compute_piston_engine_weight

compute_nacelle_weight(vehicle, ref_nacelle, NENG, WENG)[source]#

Calculates the nacelle weight based on the Raymer method Assumptions:

  1. All nacelles are identical

2) The number of nacelles is the same as the number of engines The engine weight is imported in Kg (The default RCAIDE mass unit)

Source:

Aircraft Design: A Conceptual Approach (2nd edition)

Inputs:
vehicle - data dictionary with vehicle properties [dimensionless]

-.ultimate_load: ultimate load factor of aircraft

nacelle - data dictionary for the specific nacelle that is being estimated [dimensionless]

-lenght: total length of engine [m] -diameter: diameter of nacelle [m]

WENG - dry engine weight [kg]

Outputs:

WNAC: nacelle weight [kg]

Properties Used:

N/A

compute_misc_engine_weight(vehicle, NENG, WENG)[source]#

Calculates the miscellaneous engine weight based on the Raymer method, electrical control system weight and starter engine weight Assumptions:

Source:

Aircraft Design: A Conceptual Approach

Inputs:
vehicle - data dictionary with vehicle properties [dimensionless]

-.fuselages[‘fuselage’].lengths.total: length of fuselage [m]

network - data dictionary for the specific network that is being estimated [dimensionless]

-.number_of_engines: number of engines

Outputs:

WEC: electrical engine control system weight [kg] WSTART: starter engine weight [kg]

Properties Used:

N/A

compute_fuel_system_weight(vehicle, NENG)[source]#

Calculates the weight of the fuel system based on the Raymer method Assumptions:

Source:

Aircraft Design: A Conceptual Approach

Inputs:
vehicle - data dictionary with vehicle properties [dimensionless]

-.design_mach_number: design mach number -.mass_properties.max_zero_fuel: maximum zero fuel weight [kg]

Outputs:

WFSYS: Fuel system weight [kg]

Properties Used:

N/A