Mission module
The FAST-OAD mission module allows to simulate missions and to estimate their fuel burn, which is an essential part of the sizing process.
The module aims at versatility, by:
providing a way to define missions from custom files
linking mission inputs and outputs to the FAST-OAD data model
linking or not a mission to the sizing process
Inputs and outputs of the module
The performance module, as any FAST-OAD module, is linked to the MDA process by the connection of its input and output variables. But unlike other modules, the list of inputs and outputs is not fixed, and widely depends on the mission definition.
The input variables are defined in the mission file, as described here.
Most outputs variables are automatically decided by the structure of the mission. Distance, duration and fuel burn are provided as outputs for each part of the mission.
Outputs for the whole mission:
data:mission:<mission_name>:distance
data:mission:<mission_name>:duration
data:mission:<mission_name>:fuel
Outputs for each part of the mission (flight route or flight phase):
data:mission:<mission_name>:<part_name>:distance
data:mission:<mission_name>:<part_name>:duration
data:mission:<mission_name>:<part_name>:fuel
Outputs for each flight phase of a route:
data:mission:<mission_name>:<route_name>:<phase_name>:distance
data:mission:<mission_name>:<route_name>:<phase_name>:duration
data:mission:<mission_name>:<route_name>:<phase_name>:fuel
Other mission-related variables are:
data:mission:<mission_name>:TOW
: TakeOff Weight. Input or output, depending on options below.
data:mission:<mission_name>:needed_block_fuel
: Burned fuel during mission. Output.
data:mission:<mission_name>:block_fuel
: Actual block fuel. Input or output, depending on options below.
Usage in FAST-OAD configuration file
The mission module can be used with the identifier :code`fastoad.performances.mission`.
The available parameters for this module are:
Detailed description of parameters
propulsion_id
Mandatory
It is the identifier of a registered propulsion wrapper (see How to add a custom propulsion model to FAST-OAD).
FAST-OAD comes with a parametric propulsion model adapted to engine of the 1990s, with
"fastoad.wrapper.propulsion.rubber_engine"
as identifier.
mission_file_path
Optional (Default =
"::sizing_mission"
)It is the path to the file that defines the mission. As any file path in the configuration file, it can be absolute or relative. If relative, the path of configuration file will be used as basis.
FAST-OAD comes with two embedded missions, usable with special values:
"::sizing_mission"
: a time-step simulation of a classical commercial mission with diversion and holding phases
"::sizing_breguet"
: a very quick simulation based on Breguet formula, with rough assessment of fuel consumption during climb, descent, diversion and holding phases.
out_file
Optional
If provided, a CSV file will be written at provided path with all computed flight points.
If relative, the path of configuration file will be used as basis.
mission_name
Mandatory if the used mission file defines several missions. Optional otherwise.
Sets the mission to be computed.
use_initializer_iteration
Optional (Default =
true
)During first solver loop, a complete mission computation can fail or consume useless CPU-time. When activated, this option ensures the first iteration is done using a simple, dummy, formula instead of the specified mission.
Warning
Set this option to false
if you do expect this model to be computed only once.
Otherwise, the performance computation will be done only by the initializer.
adjust_fuel
Optional (Default =
true
)If
true
, block fuel will be adjusted to fuel consumption during mission. Iffalse
, the input block fuel will be used.
compute_TOW
Optional (Default =
false
)Not used (actually forced to
true
) ifadjust_fuel
istrue
.If
true
, TakeOff Weight will be computed from mission block fuel and ZFW.If
false
, block fuel will be computed from TOW and ZFW.
add_solver
Optional (Default =
false
)Not used (actually forced to
false
) ifcompute_TOW
isfalse
.Setting this option to False will deactivate the local solver of the component. Useful if a global solver is used for the MDA problem.
is_sizing
Optional (Default =
false
)If
true
, TOW for the mission will be considered equal to MTOW and mission payload will be considered equal to design payload (variabledata:weight:aircraft:payload
). Therefore, mission computation will be linked to the sizing process.