feat(data): add airfoil data

src/airfoil_data/README.md

+# Airfoil data
+
+Rotare requires the input of airfoil polars to properly interpolate the lift and
+drag coefficient of each element. These polars can be directly provided or
+generated using external tools such as XFOIL or XFLR5.
+
+The following process explains how to generate such polars and transform them in
+a structure to be imported in Rotare. A more complete description is provided in
+the complete manual of Rotare.
+
+## polargenerator.py
+
+**polargenerator** is a small script that will run XFOIL in order to generate
+the airfoil polars. This script uses the [aeropy] library, follow the
+instructions on the Github to install it properly. (_Note: this is not the same
+`aeropy` than the one installed through `pip`).
+
+The usage is straightforward:
+
+```bash
+python polargenerator <airfoil>
+```
+
+It can either accept a NACA airfoil as input or a file with the airfoil
+coordinates. Example:
+
+```bash
+python polargenerator 'naca0012'
+python polargenerator 'myairfoil.dat'
+```
+
+Note that if the airfoil coordinates are provided though a DAT-file, the need to
+be formatted according to the `Selig` convention (see "[Airfoil Format]" section
+on the UIUC Airfoil Database). A Matlab utility is provided with the `af_tools`
+library to convert the Ledneicer format into Selig format.
+
+## MAT-file
+
+Once the raw XFOIL data have been generated for a given airfoil, they need to be
+converted into a structure that will be understood by Rotare. This is done using
+the `xf2mat` function provided by the `af_tools` library.
+
+[Airfoil Format]: https://m-selig.ae.illinois.edu/ads.html
+[aeropy]: https://github.com/leal26/AeroPy

src/airfoil_data/naca0012.dat

+NACA 0012 AIRFOILS
+       66.       66.
+
+  0.000000  0.000000
+  0.000584  0.004260
+  0.002334  0.008429
+  0.005247  0.012501
+  0.009315  0.016471
+  0.014529  0.020330
+  0.020877  0.024071
+  0.028344  0.027683
+  0.036913  0.031156
+  0.046563  0.034479
+  0.057272  0.037641
+  0.069015  0.040631
+  0.081765  0.043437
+  0.095492  0.046049
+  0.110163  0.048457
+  0.125745  0.050651
+  0.142201  0.052625
+  0.159492  0.054372
+  0.177579  0.055886
+  0.196419  0.057164
+  0.215968  0.058205
+  0.236180  0.059008
+  0.257008  0.059576
+  0.278404  0.059910
+  0.300318  0.060017
+  0.322698  0.059903
+  0.345492  0.059575
+  0.368646  0.059042
+  0.392108  0.058314
+  0.415822  0.057403
+  0.439732  0.056320
+  0.463783  0.055077
+  0.487918  0.053687
+  0.512082  0.052162
+  0.536217  0.050516
+  0.560268  0.048762
+  0.584179  0.046912
+  0.607892  0.044980
+  0.631354  0.042978
+  0.654509  0.040917
+  0.677303  0.038811
+  0.699682  0.036670
+  0.721596  0.034506
+  0.742992  0.032329
+  0.763820  0.030152
+  0.784032  0.027983
+  0.803581  0.025834
+  0.822421  0.023714
+  0.840508  0.021635
+  0.857800  0.019605
+  0.874255  0.017635
+  0.889837  0.015735
+  0.904509  0.013914
+  0.918235  0.012182
+  0.930985  0.010549
+  0.942728  0.009022
+  0.953437  0.007611
+  0.963087  0.006324
+  0.971656  0.005169
+  0.979123  0.004152
+  0.985471  0.003280
+  0.990685  0.002560
+  0.994753  0.001994
+  0.997666  0.001587
+  0.999416  0.001342
+  1.000000  0.001260
+
+  0.000000  0.000000
+  0.000584 -0.004260
+  0.002334 -0.008429
+  0.005247 -0.012501
+  0.009315 -0.016471
+  0.014529 -0.020330
+  0.020877 -0.024071
+  0.028344 -0.027683
+  0.036913 -0.031156
+  0.046563 -0.034479
+  0.057272 -0.037641
+  0.069015 -0.040631
+  0.081765 -0.043437
+  0.095492 -0.046049
+  0.110163 -0.048457
+  0.125745 -0.050651
+  0.142201 -0.052625
+  0.159492 -0.054372
+  0.177579 -0.055886
+  0.196419 -0.057164
+  0.215968 -0.058205
+  0.236180 -0.059008
+  0.257008 -0.059576
+  0.278404 -0.059910
+  0.300318 -0.060017
+  0.322698 -0.059903
+  0.345492 -0.059575
+  0.368646 -0.059042
+  0.392108 -0.058314
+  0.415822 -0.057403
+  0.439732 -0.056320
+  0.463783 -0.055077
+  0.487918 -0.053687
+  0.512082 -0.052162
+  0.536217 -0.050516
+  0.560268 -0.048762
+  0.584179 -0.046912
+  0.607892 -0.044980
+  0.631354 -0.042978
+  0.654509 -0.040917
+  0.677303 -0.038811
+  0.699682 -0.036670
+  0.721596 -0.034506
+  0.742992 -0.032329
+  0.763820 -0.030152
+  0.784032 -0.027983
+  0.803581 -0.025834
+  0.822421 -0.023714
+  0.840508 -0.021635
+  0.857800 -0.019605
+  0.874255 -0.017635
+  0.889837 -0.015735
+  0.904509 -0.013914
+  0.918235 -0.012182
+  0.930985 -0.010549
+  0.942728 -0.009022
+  0.953437 -0.007611
+  0.963087 -0.006324
+  0.971656 -0.005169
+  0.979123 -0.004152
+  0.985471 -0.003280
+  0.990685 -0.002560
+  0.994753 -0.001994
+  0.997666 -0.001587
+  0.999416 -0.001342
+  1.000000 -0.001260

src/airfoil_data/naca0015.dat

+NACA 0015
+1.0000     0.00158
+0.9500     0.01008
+0.9000     0.01810
+0.8000     0.03279
+0.7000     0.04580
+0.6000     0.05704
+0.5000     0.06617
+0.4000     0.07254
+0.3000     0.07502
+0.2500     0.07427
+0.2000     0.07172
+0.1500     0.06682
+0.1000     0.05853
+0.0750     0.05250
+0.0500     0.04443
+0.0250     0.03268
+0.0125     0.02367
+0.0000     0.00000
+0.0125     -0.02367
+0.0250     -0.03268
+0.0500     -0.04443
+0.0750     -0.05250
+0.1000     -0.05853
+0.1500     -0.06682
+0.2000     -0.07172
+0.2500     -0.07427
+0.3000     -0.07502
+0.4000     -0.07254
+0.5000     -0.06617
+0.6000     -0.05704
+0.7000     -0.04580
+0.8000     -0.03279
+0.9000     -0.01810
+0.9500     -0.01008
+1.0000     -0.00158

src/airfoil_data/polargenerator.py

+"""Generate airfoil polars automatically using XFOIL
+
+ Rotare requires the input of airfoil polars to interpolate properly the lift
+ and drag coefficient of the various elements.
+ This script automates the generation of these input polars to save some time.
+
+ Args:
+    - airfoil : str
+        Arfoil to use, either in the form of 'naca0012' or name of the DAT-file
+        with the coordinates
+
+ Script defaults:
+    - Reynolds : 1e5, 5e5, 1e6, 1.5e6, 2e6, 5e6, 1e7
+    - AOA : -25 to 25 with a step of 0.5
+    - Iter : 100
+
+ ------------------------------------------------
+ (c) Copyright 2022 University of Liege
+ Author: Thomas Lambert <t.lambert@uliege.be>
+ ULiege - Aeroelasticity and Experimental Aerodynamics
+ MIT License
+"""
+
+# Imports
+import sys
+import os
+import numpy as np
+import aeropy.xfoil_module as xf
+
+
+def main():
+    """Creates polar files for each reynolds"""
+
+    airfoil = parse_inputs()
+    reynolds = [re * 1000000 for re in [0.2, 0.5, 1, 1.5, 2, 5, 10]]
+    aoa = list(np.arange(-20, 30, 0.5))
+
+    i = 1
+    for re in reynolds:
+        print("%d/%d - Calculating polar for Re=%ge6" % (i, len(reynolds), re / 1e6))
+        i = i + 1
+
+        if airfoil.startswith("naca"):
+            xf.call(
+                airfoil,
+                alfas=aoa,
+                output="Polar",
+                Reynolds=re,
+                plots=False,
+                NACA=True,
+                iteration=500,
+            )
+        else:
+            if os.path.exists(airfoil) or os.path.exists(airfoil + ".dat"):
+                xf.call(
+                    airfoil,
+                    alfas=aoa,
+                    output="Polar",
+                    Reynolds=re,
+                    plots=False,
+                    NACA=False,
+                    iteration=500,
+                )
+            else:
+                raise ValueError("Airfoil file not foud")
+
+    cleanup(airfoil)
+
+
+def parse_inputs():
+    """Proper parsing of inputs"""
+    airfoil = sys.argv[1]
+
+    return airfoil
+
+
+def cleanup(airfoil):
+    """Remove temp files and rename files properly"""
+
+    cwd = os.getcwd()
+
+    # Remove useless files
+    safe_remove(":00.bl")
+
+    # Add proper extension to generated files
+    for file in os.listdir(cwd):
+        if file.startswith("Coordinates_"):
+            safe_rename(file, airfoil + ".dat")
+        elif file.startswith("Polar_"):
+            safe_rename(file, file + ".txt")
+
+
+def safe_remove(file):
+    """Safely remove a file"""
+    if os.path.exists(file):
+        os.remove(file)
+
+
+def safe_rename(old, new):
+    """Safely rename a file"""
+
+    if os.path.exists(new):
+        os.remove(new)
+
+    os.rename(old, new)
+
+
+# Only run when file is directly executed
+if __name__ == "__main__":
+    main()