Update settings

Author: 1-Bart-1

data/TUDELFT_V3_KITE/vsm_settings_coarse.yaml

@@ -50,6 +50,7 @@ wings:
     spanwise_direction: [0.0, 1.0, 0.0] # Unit vector defining wingspan direction
     remove_nan: true # Remove NaN values from polar data
     use_prior_polar: true # Use previously computed polars if available
+    billowing_angle: 5 # [deg] Half-angle of circular arc billowing
 
 # Numerical method settings and convergence criteria
 solver_settings:

examples/billowing.jl

@@ -5,7 +5,6 @@ using DelimitedFiles
 
 PLOT = true
 USE_TEX = false
-BILLOWING_ANGLE = billowing_angle_from_percentage(5)  # Half-angle of billowing arc [rad]
 
 # Data paths (all within this repo)
 project_dir = dirname(dirname(pathof(VortexStepMethod)))
@@ -20,6 +19,23 @@ literature_paths = [
     joinpath(lit_dir, "python_alpha_sweep.csv"),
     joinpath(lit_dir, "windtunnel_alpha_sweep_beta_00_0_Poland_2025_Rey_5e5.csv"),
 ]
+
+# Load solver settings (coarse: 36 panels, matches 10-section geometry)
+settings_data = VortexStepMethod.YAML.load_file(
+    joinpath(v3_dir, "vsm_settings_coarse.yaml"))
+condition_cfg = settings_data["condition"]
+solver_cfg = settings_data["solver_settings"]
+wing_cfg = settings_data["wings"][1]
+n_panels = wing_cfg["n_panels"]
+
+# Read billowing angle from settings (degrees → radians, or from percentage)
+if haskey(wing_cfg, "billowing_percentage")
+    BILLOWING_ANGLE = billowing_angle_from_percentage(
+        wing_cfg["billowing_percentage"])
+else
+    BILLOWING_ANGLE = deg2rad(get(wing_cfg, "billowing_angle", 0.0))
+end
+
 labels = [
     "VSM flat",
     "VSM billowing $(round(Int, rad2deg(BILLOWING_ANGLE)))°",
@@ -29,13 +45,6 @@ labels = [
     "WindTunnel Re=5e5",
 ]
 
-# Load solver settings (coarse: 36 panels, matches 10-section geometry)
-settings_data = VortexStepMethod.YAML.load_file(
-    joinpath(v3_dir, "vsm_settings_coarse.yaml"))
-condition_cfg = settings_data["condition"]
-solver_cfg = settings_data["solver_settings"]
-n_panels = settings_data["wings"][1]["n_panels"]
-
 # Load coarse geometry (10 structural rib sections)
 geom_data = VortexStepMethod.YAML.load_file(
     joinpath(v3_dir, "aero_geometry_coarse_discretisation.yaml"))

src/settings.jl

@@ -34,8 +34,13 @@ Settings for a single wing, used within [`VSMSettings`](@ref).
     (default `true`)
 - `use_prior_polar`: Reuse prior refined/panel polar mapping on
     reinit/refine updates (default `false`)
-- `billowing_angle`: Half-angle of circular arc billowing in radians
-    (default `0.0`; only used with `BILLOWING` distribution)
+- `billowing_angle`: Half-angle of circular arc billowing in degrees
+    (default `0.0`; only used with `BILLOWING` distribution).
+    Converted to radians internally.
+    Mutually exclusive with `billowing_percentage`.
+- `billowing_percentage`: Percentage by which the chord is shorter than
+    the minor arc (default `nothing`; converted to `billowing_angle`).
+    Mutually exclusive with `billowing_angle`.
 """
 @with_kw mutable struct WingSettings
     name::String = "main_wing"
@@ -173,7 +178,21 @@ function VSMSettings(filename; data_prefix=true)
             end
             wing.remove_nan = wing_data["remove_nan"]
             wing.use_prior_polar = get(wing_data, "use_prior_polar", false)
-            wing.billowing_angle = get(wing_data, "billowing_angle", 0.0)
+
+            has_angle = haskey(wing_data, "billowing_angle")
+            has_pct   = haskey(wing_data, "billowing_percentage")
+            if has_angle && has_pct
+                throw(ArgumentError(
+                    "Wing '$(wing.name)': specify either " *
+                    "billowing_angle or billowing_percentage, " *
+                    "not both"))
+            elseif has_pct
+                wing.billowing_angle =
+                    billowing_angle_from_percentage(
+                        wing_data["billowing_percentage"])
+            elseif has_angle
+                wing.billowing_angle = deg2rad(wing_data["billowing_angle"])
+            end
 
             push!(vsm_settings.wings, wing)
             n_panels += wing.n_panels