bladex.profilebase.ProfileBase.interpolate_coordinates

ProfileBase.interpolate_coordinates(num=500, radius=1.0)[source]

Interpolate the airfoil coordinates from the given data set of discrete points.

The interpolation applies the Radial Basis Function (RBF) method, to construct approximations of the two functions that correspond to the airfoil upper half and lower half coordinates. The RBF implementation is present in RBF ndinterpolator.

References:

Buhmann, Martin D. (2003), Radial Basis Functions: Theory and Implementations. http://www.cs.bham.ac.uk/~jxb/NN/l12.pdf https://www.cc.gatech.edu/~isbell/tutorials/rbf-intro.pdf

Parameters:
  • num (int) – number of interpolated points. Default value is 500
  • radius (float) – range of the cut-off radius necessary for the RBF interpolation. Default value is 1.0. It is quite necessary to adjust the value properly so as to ensure a smooth interpolation
Returns:

interpolation points for the airfoil upper half X-component, interpolation points for the airfoil lower half X-component, interpolation points for the airfoil upper half Y-component, interpolation points for the airfoil lower half Y-component
Return type:

numpy.ndarray, numpy.ndarray, numpy.ndarray, numpy.ndarray
Raises:
  • TypeError – if num is not of type int
  • ValueError – if num is not positive, or if radius is not positive