Some quote from Paula Echeverri’s article on
https://blog.x.company/sharing-makani-with-the-world-the-energy-kite-collection-ea49398df78c :
Although this is the end for Makani, by open sourcing our work and story we hope to create tailwinds for the next generation of scientists, inventors and moonshot takers to tackle the near-impossible.
And from the Part I , page 13:
1.3 Shortcomings of the M600
The M600 was shown to have several shortcomings. Among these were:
● The novel, untested airfoil design made rosy assumptions about the CL,max that could be
reliably achieved in flight, along with overly optimistic CD
targets.
● As a result, the system L/D (i.e. including parasitic tether drag) was insufficient to
produce the assumed “glide speed”
● The sizing of the wing, combined with lower than expected lift and higher than expected
drag resulted in low power performance
● The roll-stiffening effect of a very tall bridle
rendered the ailerons unable to exert
sufficient roll authority to fly small loops, which are important to power production
● The potential energy swings resulting from large loops forced us into large speed
variations. At low winds, we’re often flying much faster than optimum at the bottom of
the path, and at high winds, we must fly much slower than optimum at the top of the
path to prevent overspeeding at the bottom.
● The resulting large differences in airspeed disallowed the rotors from operating at peak
extraction capability through much of the loop
I note some similarity between:
● The potential energy swings resulting from large loops forced us into large speed
variations. At low winds, we’re often flying much faster than optimum at the bottom of
the path, and at high winds, we must fly much slower than optimum at the top of the
path to prevent overspeeding at the bottom.
And what I wrote above before knowing Makani’s analysis:
It is clear that shortcomings and negative power curves on the videos of M600 (unlike the smaller Wing4e) can be revealed at the end of this project.
All this information is a real treasure and marks the end of a first AWE stage (if not the end of AWE) and the study of new architectures and new flight plans.