RCAIDE.Library.Methods.Mass_Properties.Weight_Buildups.Conventional.Transport.FLOPS.compute_propulsion_system_weight
compute_propulsion_system_weight#
- compute_propulsion_system_weight(vehicle, ref_propulsor)[source]#
Computes the complete propulsion system weight using NASA FLOPS weight estimation method. Includes engines, nacelles, thrust reversers, and associated systems.
- Parameters:
vehicle (Vehicle) –
- The vehicle instance containing:
- networkslist
- Propulsion systems with:
- propulsorslist
Engine data
- fuel_lineslist
Fuel system data with fuel tanks
- design_mach_numberfloat
Design cruise Mach number
- mass_properties.max_zero_fuelfloat
Maximum zero fuel weight [kg]
- systems.accessoriesstr
Aircraft type (‘short-range’, ‘commuter’, ‘medium-range’, ‘long-range’, ‘sst’, ‘cargo’)
ref_propulsor (Propulsor) –
- Reference engine containing:
- sealevel_static_thrustfloat
Sea level static thrust [N]
- nacelleNacelle
- Nacelle geometry with:
- diameterfloat
Maximum diameter [m]
- lengthfloat
Total length [m]
- Returns:
output –
- Container with propulsion weight breakdown:
- W_propfloat
Total propulsion system weight [kg]
- W_enginefloat
Dry engine weight [kg]
- W_thrust_reverserfloat
Thrust reverser weight [kg]
- W_starterfloat
Starter system weight [kg]
- W_engine_controlsfloat
Engine controls weight [kg]
- W_fuel_systemfloat
Fuel system weight [kg]
- W_nacellefloat
Nacelle weight [kg]
- number_of_enginesint
Total engine count
- number_of_fuel_tanksint
Total fuel tank count
- Return type:
Notes
Uses FLOPS correlations developed from transport aircraft database.
- Major Assumptions
Engines have a thrust to weight ratio of 5.5
All nacelles are identical
Number of nacelles equals number of engines
Number of thrust reversers equals the number of engines unless there is an odd number of engines in which case it is N - 1
Theory Engine weight is computed using: .. math:
W_{eng} = THRUST/5.5
Nacelle weight is computed using: .. math:
W_{nac} = 0.25N_{nac}D_{nac}L_{nac}T^{0.36}
Thrust reverser weight is computed using: .. math:
W_{rev} = 0.034T N_{nac}
- where:
W_base = baseline engine weight
T = sea level static thrust
N_nac = number of nacelles
D_nac = nacelle diameter
L_nac = nacelle length
References
[1] NASA Flight Optimization System (FLOPS)
- compute_nacelle_weight(ref_propulsor, ref_nacelle, NENG)[source]#
Calculates the nacelle weight based on the FLOPS method
- Assumptions:
All nacelles are identical
The number of nacelles is the same as the number of engines
- Source:
The Flight Optimization System Weight Estimation Method
- Inputs:
- ref_propulsor - data dictionary for the specific network that is being estimated [dimensionless]
-.number_of_engines: number of engines -.engine_lenght: total length of engine [m] -.sealevel_static_thrust: sealevel static thrust of engine [N]
- nacelle.
-.diameter: diameter of nacelle [m]
WENG - dry engine weight [kg]
- Outputs:
WNAC: nacelle weight [kg]
- Properties Used:
N/A
- compute_thrust_reverser_weight(ref_propulsor, NENG)[source]#
Calculates the weight of the thrust reversers of the aircraft
Assumptions:
- Source:
The Flight Optimization System Weight Estimation Method
- Inputs:
- ref_propulsor - data dictionary for the specific network that is being estimated [dimensionless]
-.number_of_engines: number of engines -.sealevel_static_thrust: sealevel static thrust of engine [N]
- Outputs:
WTHR: Thrust reversers weight [kg]
- Properties Used:
N/A
- compute_misc_propulsion_system_weight(vehicle, ref_propulsor, ref_nacelle, NENG)[source]#
Calculates the miscellaneous engine weight based on the FLOPS method, electrical control system weight and starter engine weight
- Assumptions:
All nacelles are identical
The number of nacelles is the same as the number of engines
- Source:
The Flight Optimization System Weight Estimation Method
- Inputs:
- vehicle - data dictionary with vehicle properties [dimensionless]
-.design_mach_number: design mach number
- ref_propulsor - data dictionary for the specific network that is being estimated [dimensionless]
-.number_of_engines: number of engines -.sealevel_static_thrust: sealevel static thrust of engine [N]
- nacelle
-.diameter: diameter of nacelle [m]
- 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 FLOPS method Assumptions:
- Source:
The Flight Optimization System Weight Estimation Method
- Inputs:
- vehicle - data dictionary with vehicle properties [dimensionless]
-.design_mach_number: design mach number - [kg]
- Outputs:
WFSYS: Fuel system weight [kg]
- Properties Used:
N/A
- compute_engine_weight(vehicle, ref_propulsor)[source]#
Calculates the dry engine weight based on the FLOPS method Assumptions:
Rated thrust per scaled engine and rated thurst for baseline are the same Engine weight scaling parameter is 1.15 Enginge inlet weight scaling exponent is 1 Baseline inlet weight is 0 lbs as in example files FLOPS Baseline nozzle weight is 0 lbs as in example files FLOPS
- Source:
The Flight Optimization System Weight Estimation Method
- Inputs:
- vehicle - data dictionary with vehicle properties [dimensionless]
- -.systems.accessories: type of aircraft (short-range, commuter
medium-range, long-range, sst, cargo)
- ref_propulsor - data dictionary for the specific network that is being estimated [dimensionless]
-.sealevel_static_thrust: sealevel static thrust of engine [N]
- Outputs:
WENG: dry engine weight [kg]
- Properties Used:
N/A