add type AeroData (#86)

* add type AeroData

* Add POLAR_MATRIX

* use both POLAR_DATA and POLAR_MATRIX

* bugfix

* improve docstring

* improve docstring

* rename to POLAR_VECTORS and POLAR_MATRICES

* improve docstring

* improve docstring

Author: ufechner7

docs/src/types.md

@@ -16,6 +16,11 @@ PosVector
 VelVector
 ```
 
+## Aerodynamic data
+```@docs
+AeroData
+```
+
 ## Wing Geometry, Panel and Aerodynamics
 A body is constructed of one or more abstract wings. An abstract wing can be a Wing or a KiteWing. 
 A Wing/ KiteWing has one or more sections.

src/VortexStepMethod.jl

@@ -24,7 +24,7 @@ export add_section!, set_va!
 export calculate_span, calculate_projected_area
 export menu, MVec3
 export Model, VSM, LLT
-export AeroModel, LEI_AIRFOIL_BREUKELS, POLAR_DATA, INVISCID
+export AeroModel, LEI_AIRFOIL_BREUKELS, POLAR_VECTORS, POLAR_MATRICES, INVISCID
 export PanelDistribution, LINEAR, COSINE, COSINE_VAN_GARREL, SPLIT_PROVIDED, UNCHANGED
 export InitialGammaDistribution, ELLIPTIC, ZEROS
 
@@ -72,18 +72,22 @@ Enumeration of the implemented model types.
 @enum Model VSM LLT
 
 """
-   AeroModel `LEI_AIRFOIL_BREUKELS` `POLAR_DATA` `INVISCID`
+   AeroModel `LEI_AIRFOIL_BREUKELS` `POLAR_VECTORS` `POLAR_MATRICES` `INVISCID`
 
-Enumeration of the implemented aerodynamic models.
+Enumeration of the implemented aerodynamic models. See also: [AeroData](@ref)
 
 # Elements
 - `LEI_AIRFOIL_BREUKELS`: Polynom approximation for leading edge inflatable kites
-- `POLAR_DATA`: Polar data (lookup tables with interpolation)
+- `POLAR_VECTORS`: Polar vectors as function of alpha (lookup tables with interpolation)
+- `POLAR_MATRICES`: Polar matrices as function of alpha and beta (lookup tables with interpolation)
 - INVISCID
+
+where `alpha` is the angle of attack, `beta` is trailing edge angle.
 """
 @enum AeroModel begin
    LEI_AIRFOIL_BREUKELS
-   POLAR_DATA
+   POLAR_VECTORS
+   POLAR_MATRICES
    INVISCID
 end
 
@@ -120,6 +124,30 @@ Enumeration of the implemented initial gamma distributions.
 
 abstract type AbstractWing end
 
+"""
+    AeroData= Union{
+        Nothing,
+        NTuple{2, Float64},
+        Tuple{Vector{Float64}, Vector{Float64}, Vector{Float64}, Vector{Float64}},
+        Tuple{Vector{Float64}, Vector{Float64}, Matrix{Float64}, Matrix{Float64}, Matrix{Float64}}
+    }
+
+Union of different definitions of the aerodynamic properties of a wing section. See also: [AeroModel](@ref)
+  - nothing for INVISCID
+  - (`tube_diameter`, camber) for `LEI_AIRFOIL_BREUKELS`
+  - (`alpha_range`, `cl_vector`, `cd_vector`, `cm_vector`) for `POLAR_VECTORS`
+  - (`alpha_range`, `beta_range`, `cl_matrix`, `cd_matrix`, `cm_matrix`) for `POLAR_MATRICES` 
+
+where `alpha` is the angle of attack, `beta` is trailing edge angle, `cl` the lift coefficient,
+`cd` the drag coefficient and `cm` the pitching moment coefficient.
+"""
+const AeroData = Union{
+        Nothing,
+        NTuple{2, Float64},
+        Tuple{Vector{Float64}, Vector{Float64}, Vector{Float64}, Vector{Float64}},
+        Tuple{Vector{Float64}, Vector{Float64}, Matrix{Float64}, Matrix{Float64}, Matrix{Float64}}
+    }
+
 function menu()
    Main.include("examples/menu.jl")
 end

src/kite_geometry.jl

@@ -287,7 +287,7 @@ function KiteWing(obj_path, dat_path; alpha=0.0, crease_frac=0.75, wind_vel=10.,
         else
             TE_point = LE_point .+ [te_interp(gamma) - le_interp(gamma), 0.0, 0.0]
         end
-        push!(sections, Section(LE_point, TE_point, POLAR_DATA, aero_data))
+        push!(sections, Section(LE_point, TE_point, POLAR_MATRICES, aero_data))
     end
 
     KiteWing(n_panels, spanwise_panel_distribution, spanwise_direction, sections, sections,

src/panel.jl

@@ -119,17 +119,17 @@ function init_aero!(
         throw(ArgumentError("Both sections must have the same aero model, not $(panel.aero_model) and $aero_model_2"))
     end
 
-    if panel.aero_model === LEI_AIRFOIL_BREUKELS
+    if panel.aero_model == LEI_AIRFOIL_BREUKELS
         panel.cl_coeffs, panel.cd_coeffs, panel.cm_coeffs = compute_lei_coeffs(section_1, section_2)
 
-    elseif panel.aero_model === POLAR_DATA
+    elseif panel.aero_model in (POLAR_VECTORS, POLAR_MATRICES)
         aero_1 = section_1.aero_data
         aero_2 = section_2.aero_data
         if !all(size.(aero_1) .== size.(aero_2))
             throw(ArgumentError("Polar data must have same shape"))
         end
 
-        if length(aero_1) == 4
+        if panel.aero_model == POLAR_VECTORS
             !all(isapprox.(aero_1[1], aero_2[1])) && @error "Make sure you use the same alpha range for all your interpolations."
 
             polar_data = (
@@ -143,7 +143,7 @@ function init_aero!(
             panel.cd_interp = linear_interpolation(alphas, polar_data[2]; extrapolation_bc=NaN)
             panel.cm_interp = linear_interpolation(alphas, polar_data[3]; extrapolation_bc=NaN)
 
-        elseif length(aero_1) == 5
+        elseif panel.aero_model == POLAR_MATRICES
             !all(isapprox.(aero_1[1], aero_2[1])) && @error "Make sure you use the same alpha range for all your interpolations."
             !all(isapprox.(aero_1[2], aero_2[2])) && @error "Make sure you use the same beta range for all your interpolations."
 
@@ -314,14 +314,10 @@ function calculate_cl(panel::Panel, alpha::Float64)::Float64
         end
     elseif panel.aero_model == INVISCID
         cl = 2π * alpha
-    elseif panel.aero_model == POLAR_DATA
-        if isa(panel.cl_interp, I1)
-            cl = panel.cl_interp(alpha)::Float64
-        elseif isa(panel.cl_interp, I2)
-            cl = panel.cl_interp(alpha, 0.0)::Float64
-        else
-            throw(ArgumentError("cl_interp is $(panel.cl_interp)"))
-        end
+    elseif panel.aero_model == POLAR_VECTORS
+        cl = panel.cl_interp(alpha)::Float64
+    elseif panel.aero_model == POLAR_MATRICES
+        cl = panel.cl_interp(alpha, 0.0)::Float64
     else
         throw(ArgumentError("Unsupported aero model: $(panel.aero_model)"))
     end
@@ -342,14 +338,12 @@ function calculate_cd_cm(panel::Panel, alpha::Float64)
         if abs(alpha) > (π/9)  # Outside ±20 degrees
             cd = 2 * sin(alpha)^3
         end
-    elseif panel.aero_model == POLAR_DATA
-        if isa(panel.cd_interp, I1)
-            cd = panel.cd_interp(alpha)::Float64
-            cm = panel.cm_interp(alpha)::Float64
-        elseif isa(panel.cd_interp, I2)
-            cd = panel.cd_interp(alpha, 0.0)::Float64
-            cm = panel.cm_interp(alpha, 0.0)::Float64
-        end
+    elseif panel.aero_model == POLAR_VECTORS
+        cd = panel.cd_interp(alpha)::Float64
+        cm = panel.cm_interp(alpha)::Float64
+    elseif panel.aero_model == POLAR_MATRICES    
+        cd = panel.cd_interp(alpha, 0.0)::Float64
+        cm = panel.cm_interp(alpha, 0.0)::Float64
     elseif !(panel.aero_model == INVISCID)
         throw(ArgumentError("Unsupported aero model: $(panel.aero_model)"))
     end

src/wing_geometry.jl

@@ -8,22 +8,13 @@ Represents a wing section with leading edge, trailing edge, and aerodynamic prop
 - `LE_point::MVec3` = zeros(MVec3): Leading edge point coordinates
 - `TE_point::MVec3` = zeros(MVec3): Trailing edge point coordinates
 - `aero_model`::AeroModel = INVISCID: [AeroModel](@ref)
-- `aero_data` = nothing: Can be:
-  - nothing for INVISCID
-  - (`tube_diameter`, camber) for `LEI_AIRFOIL_BREUKELS`
-  - (`alpha_range`, `cl_vector`, `cd_vector`, `cm_vector`) for `POLAR_DATA`
-  - (`alpha_range`, `beta_range`, `cl_matrix`, `cd_matrix`, `cm_matrix`) for `POLAR_DATA`        
+- `aero_data`::AeroData = nothing: See: [AeroData]    
 """
 @with_kw mutable struct Section
     LE_point::MVec3 = zeros(MVec3)
     TE_point::MVec3 = zeros(MVec3)
     aero_model::AeroModel = INVISCID
-    aero_data::Union{
-        Nothing,
-        NTuple{2, Float64},
-        Tuple{Vector{Float64}, Vector{Float64}, Vector{Float64}, Vector{Float64}},
-        Tuple{Vector{Float64}, Vector{Float64}, Matrix{Float64}, Matrix{Float64}, Matrix{Float64}}
-    } = nothing
+    aero_data::AeroData = nothing
 end
 """
     Section(LE_point::Vector{Float64}, TE_point::Vector{Float64}, 
@@ -130,14 +121,10 @@ Add a new section to the wing.
 - LE_point::PosVector: [PosVector](@ref) of the point on the side of the leading edge
 - TE_point::PosVector: [PosVector](@ref) of the point on the side of the trailing edge
 - `aero_model`::AeroModel: [AeroModel](@ref)
-- `aero_data`: Can be:
-  - nothing for INVISCID
-  - (`tube_diameter`, camber) for `LEI_AIRFOIL_BREUKELS`
-  - (`alpha_range`, `cl_vector`, `cd_vector`, `cm_vector`) for `POLAR_DATA`
-  - (`alpha_range`, `beta_range`, `cl_matrix`, `cd_matrix`, `cm_matrix`) for `POLAR_DATA`  
+- `aero_data`::AeroData: See [AeroData](@ref)  
 """
 function add_section!(wing::Wing, LE_point::Vector{Float64}, 
-                     TE_point::Vector{Float64}, aero_model::AeroModel, aero_data=nothing)
+                     TE_point::Vector{Float64}, aero_model::AeroModel, aero_data::AeroData=nothing)
     push!(wing.sections, Section(LE_point, TE_point, aero_model, aero_data))
     return nothing
 end
@@ -258,15 +245,15 @@ function calculate_new_aero_data(aero_model,
         throw(ArgumentError("Different aero models over the span are not supported"))
     end
 
-    if model_type === INVISCID
+    if model_type == INVISCID
         return nothing
 
-    elseif model_type === POLAR_DATA
+    elseif model_type in (POLAR_VECTORS, POLAR_MATRICES)
         polar_left = aero_data[section_index]
         polar_right = aero_data[section_index + 1]
 
         # Unpack polar data
-        if length(polar_left) == 4
+        if model_type == POLAR_VECTORS
             alpha_left, CL_left, CD_left, CM_left = polar_left
             alpha_right, CL_right, CD_right, CM_right = polar_right
 
@@ -281,7 +268,7 @@ function calculate_new_aero_data(aero_model,
 
             return (alpha_left, CL_data, CD_data, CM_data)
 
-        elseif length(polar_left) == 5
+        elseif model_type == POLAR_MATRICES
             alpha_left, beta_left, CL_left, CD_left, CM_left = polar_left
             alpha_right, beta_right, CL_right, CD_right, CM_right = polar_right
 

test/bench.jl

@@ -99,7 +99,7 @@ using LinearAlgebra
         cms = [-0.1 * α for α in alphas]
 
         for model in models
-            for (aero_model, aero_data) in [(INVISCID, nothing), (POLAR_DATA, (alphas, cls, cds, cms))]
+            for (aero_model, aero_data) in [(INVISCID, nothing), (POLAR_VECTORS, (alphas, cls, cds, cms))]
                 wing = Wing(n_panels, spanwise_panel_distribution=LINEAR)
                 add_section!(wing, 
                     [0.0, span/2, 0.0],    # Left tip LE 

test/test_panel.jl

@@ -137,8 +137,8 @@ end
     end
 
     # Create two sections with slightly different polar data
-    section1 = Section([0.0, 0.0, 0.0], [1.0, 0.0, 0.0], POLAR_DATA, polar_data)
-    section2 = Section([0.0, 10.0, 0.0], [1.0, 10.0, 0.0], POLAR_DATA, big_polar_data)
+    section1 = Section([0.0, 0.0, 0.0], [1.0, 0.0, 0.0], POLAR_VECTORS, polar_data)
+    section2 = Section([0.0, 10.0, 0.0], [1.0, 10.0, 0.0], POLAR_VECTORS, big_polar_data)
 
     # Create panel
     panel = create_panel(section1, section2)