Data structure basics

Performance and design data is held largely in the par arrays (a holdover from FORTRAN TASOPT) along with a growing body of structs to represent cohesive components and systems. An aircraft struct wraps these arrays, structs, and auxiliary information.

par arrays

Four arrays contain both prescribed inputs and computed outputs, some of which are multi-dimensional:

• parg::AbstractVector{Float64}: geometric quantities, weights, structural values, and other values inherent to an instantiated design (not operation).
• parm::AbstractArray{Float64, 2}: mission-prescribing parameters. The second dimension allows the specification of multiple mission profiles.
• para::AbstractArray{Float64, 3}: aerodynamic performance quantities. The second dimension captures the variation over a mission. The third dimension allows the specification of multiple mission profiles.
• pare::AbstractArray{Float64, 3}: engine perfomance quantities. As for para, the second and third dimensions capture flight-point and mission dependencies, respectively.

Data in the par arrays are accessed via Integer indices defined at src/data_structs/index.inc. These indices can be added to a namespace via include(__TASOPTindices__):

using TASOPT
#using __TASOPTroot__, which fetches the src directory
include(joinpath(__TASOPTroot__, "data_structs/index.inc"))

#or more concisely
include(__TASOPTindices__)

The variable names of these indices indicate which par array they should access and hint at the quantity in question. For example, ieTfuel evaluates to 2 and retrieves the model's fuel temperature via pare[ieTfuel].

Note that for the multi-dimensional par arrays, indexing with a single Integer only retrieves the value for the first flight point of the first mission (namely, the design mission). Additional indexing is required to access data from different flight points or missions. Indices for specific flight points are defined in index.inc and should be used when indexing pare or para, e.g., ipstatic for static ground condition or ipcruise1 for the start of cruise.

using TASOPT
include(__TASOPTindices__)
ac = load_default_model()

println("Single element: ", size(ac.pare[ieTfuel]))
println(ac.pare[ieTfuel])

println("Full slices: ", size(ac.pare[ieTfuel,:,:]))
println(ac.pare[ieTfuel,:,:])

println("All missions at cruise start: ", size(ac.pare[ieTfuel,ipcruise1,:]))
println(ac.pare[ieTfuel,ipcruise1,:])

Loading default aircraft model
[ Info: No template input file provided. Proceeding with template file as determined by design mission range.
[ Info: Template input file selected: /home/runner/work/TASOPT.jl/TASOPT.jl/src/../example/defaults/default_input.toml
Single element: ()
280.0
Full slices: (17, 2)
[280.0 280.0; 280.0 280.0; 280.0 280.0; 280.0 280.0; 280.0 280.0; 280.0 280.0; 280.0 280.0; 280.0 280.0; 280.0 280.0; 280.0 280.0; 280.0 280.0; 280.0 280.0; 280.0 280.0; 280.0 280.0; 280.0 280.0; 280.0 280.0; 280.0 280.0]
All missions at cruise start: (2,)
[280.0, 280.0]

can be included via the convenience variable __TASOPTindices__

aircraft struct

An aircraft is composed of par array fields, title and description fields, and a is_sized flag to indicate its status. An optional fuse_tank field is present as a trial for future struct-based development. All fields are dot-accessible and array elements can be changed (e.g., ac.parg[igS] = 20), though the struct itself is not mutable.

Refer to the struct reference page for add'l details.