CFACS: Constrained Fitting for Airfoil Curvature Smoothing(LAR-17227-1)

Airfoil smoothing in design environments is largely based on heuristic methods and it is an art to generate an unbiased smooth fit of the airfoil's curvature profile by modifying its geometry. The software CFACS (Constrained Fitting for Airfoil Curvature Smoothing) uses a spline-based airfoil smoothing method with the sum of squares of the third derivative jumps as a curvature smoothness measure. CFACS can take out dramatic curvature oscillations with extremely small geometry changes and smooth an airfoil segment without creating curvature oscillations near the endpoints. Visually, CFACS generates an unbiased smooth fit of the curvature profile. CFACS can smooth airfoils to either promote desirable performance characteristics or remove undesirable pressure field oscillations in computational fluid dynamics solutions.