Macro Airfoil Import & Scale

Description
This Macro, when run, will first provide the user with a file browser to locate and select a .dat airfoil text file. Once selected, a chord length is entered and upon pressing the OK button, a properly scaled airfoil is produced. There are two versions provided here. Version 1.5 should work on FreeCAD versions, 0.13 stable as well as all 0.14 versions. Version 2 should only be used with FreeCAD versions equal to or greater than 0.14 3077 and will work best with versions built with OCE/OCC versions 6.7 or greater.

See also Common Airfoil Data Import



Select The File
Running the Macro will first present the user with a file browser that will allow you to select the desired airfoil .dat file. Browse to where you have saved the airfoil file, select it and press Open.



Enter Chord Length
Once the airfoil file has been selected, a new dialog will appear asking for a chord length. Any length may be entered, in millimeters. Once your desired length is entered, the Macro will produce a Draft Wire (DWire) following the points described in the previously selected .dat airfoil file at the scale you entered for the chord length.



The Airfoil, properly scaled, should now be ready for use in your project.

How To Use - Version 2
File selection is the same as version 1.5. With version 2 you now have the choice to either have the resulting airfoil made with a Draft Wire (DWire) or a Basic Spline (BSpline). As with version 1.5, you enter the desired chord length. Additionally you can now select which type of foil you want. Simply click on the BSpline radio button or leave as is for for the default DWire.



Latest
The lastest version of the macro is to be found at EllipseCenter2Points.FCMacro but the easiest way to install this macro is through the Addon Manager.

Version 1.5
Macro_Airfoil_Import_&_Scale.FCMacro

Editing The Default Selection
If you primarily wish to have your imported and scaled airfoils made with BSplines rather than DWires, the Marco may be edited to default to the Bspline. This is done by editing the line -

- and changing it to -

A note on this is included within the text of the macro.

Version 2

 * 1) AIRFOIL IMPORT & SCALE v2.
 * 2) Imports and scales an Airfoil in the form of a Draft Wire (DWire) or Basic Spline (BSpline)
 * 3) For FreeCAD Versions = or > 0.14 Revision 3077
 * 4) Works best with OCC/OCE = or > 6.7
 * 1) Imports and scales an Airfoil in the form of a Draft Wire (DWire) or Basic Spline (BSpline)
 * 2) For FreeCAD Versions = or > 0.14 Revision 3077
 * 3) Works best with OCC/OCE = or > 6.7
 * 1) Works best with OCC/OCE = or > 6.7
 * 1) Works best with OCC/OCE = or > 6.7

from PySide import QtCore, QtGui from PySide.QtGui import QLineEdit, QRadioButton import FreeCAD, FreeCADGui, Draft import importAirfoilDAT


 * 1) Select .dat airfoil data file to be imported

filename = QtGui.QFileDialog.getOpenFileName(QtGui.qApp.activeWindow,'Open An Airfoil File','*.dat')

class p:

def proceed(self): if self.radio1.isChecked: try: # This produces a scaled Airfoil with a DWire

scalefactor=float(self.s1.text) f1=str(filename) importAirfoilDAT.insert(f1,"Unnamed") Draft.scale(App.ActiveDocument.ActiveObject,delta=App.Vector(scalefactor,scalefactor,scalefactor),center=App.Vector(0,0,0),legacy=True) except: FreeCAD.Console.PrintError("Error, not a valid .dat file\n")

self.close

if self.radio2.isChecked: try:

# This produces a scaled Airfoil with a BSpline

scalefactor=float(self.s1.text) f1=str(filename) importAirfoilDAT.insert(f1,"Unnamed") points = FreeCAD.ActiveDocument.ActiveObject.Points Draft.makeBSpline(points, closed=True) Draft.scale(App.ActiveDocument.ActiveObject,delta=App.Vector(scalefactor,scalefactor,scalefactor),center=App.Vector(0,0,0),legacy=True) App.getDocument("Unnamed").removeObject("DWire")

except: FreeCAD.Console.PrintError("Error, not a valid .dat file\n")

self.close

def close(self): self.dialog.hide

def __init__(self): self.dialog = None self.s1 = None

# Make dialog box and get the scale size

self.dialog = QtGui.QDialog self.dialog.resize(350,100) self.dialog.setWindowTitle("Airfoil Import & Scale") la = QtGui.QVBoxLayout(self.dialog) t1 = QtGui.QLabel("Chord Length") la.addWidget(t1) self.s1 = QtGui.QLineEdit la.addWidget(self.s1)

# Add radio buttons to select between DWire and BSpline

self.radio1 = QRadioButton("Make DWire") self.radio2 = QRadioButton("Make BSpline")

# set default to DWire & make radio buttons - Change self.radio1.setChecked(True) to           # self.radio2.setChecked(True) to set BSpline as default

self.radio1.setChecked(True) la.addWidget(self.radio1) la.addWidget(self.radio2)

# Add OK / Cancel buttons

okbox = QtGui.QDialogButtonBox(self.dialog) okbox.setOrientation(QtCore.Qt.Horizontal) okbox.setStandardButtons(QtGui.QDialogButtonBox.Cancel|QtGui.QDialogButtonBox.Ok) la.addWidget(okbox) QtCore.QObject.connect(okbox, QtCore.SIGNAL("accepted"), self.proceed) QtCore.QObject.connect(okbox, QtCore.SIGNAL("rejected"), self.close) QtCore.QMetaObject.connectSlotsByName(self.dialog) self.dialog.show self.dialog.exec_

p

Link
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UIUC Applied Aerodynamics Group Departement of Aerospace Engineering