Is it possible that HARP_Opt do not calculate blade geometry itself (Chord and Twist distribution) but import from a file and do analysis?
It is not possible to input blade geometry directly into HARP_Opt, but actually there is a way to achieve a similar effect. You can hold the chord, twist, and/or thickness distributions constant by setting the upper and lower bounds to the same values. You may have to adjust the values of the bounds by trial and error to achieve your desired blade geometry. HARP_Opt uses Bézier curves to define the blade geometry, so essentially what you would be doing is a “best-fit” Bézier curve to get your desired shape.
Hope this helps.
University of Washington