Remodeling the B-series geometry in a CAD environment

The generation of a propeller surface in a CAD environment using non-uniform rational B-splines is described. A universal chordwise knot vector for both 2D (sections) and 3D (surfaces) is given including modified boundary conditions for improved handling of piecewise monotonicity. A method to smooth the chordwise thickness distribution is presented and applied to several legacy sections. The buildup of the surface in 3D and a volumetric grid topology for CFD is described and demonstrated using the venerable B4-70 propeller as a case study object.