By Dave Santos on August 5, 2019

28025Scaling Post flagged on New Forum

Not sure what the problem was with the New Forum post flagged below, I thought the scaling topic was going well; maybe the flag refers to Pierre's impression that I was "confusing" scaling effects he found "clear". Reposting the flagged post here, and leaving the New Forum aside for now, until immoderate Moderation moderates.

-------------- flagged post -----------------

[Tallak had questioned how much nominal cruise speed data correlates with stall speed]

Obviously stall speed strongly correlates to cruise speed; I merely grabbed the first scaling graph in search to show what sort of scaling data all the fast AWES kiteplane ventures have been “clueless” about.

An equivalently loaded (powered-up) kite the size of a 747 does recruit the mass of the actual 747 via the anchor. 75msec is Cat5 hurricane velocity, many times beyond probable wind. In this power class, a soft kite’s lower stall speed is highly favored, not to mention its crashworthiness.

Tether scaling also is function of the kite window. German weather kites of <10m WS reached ~10km high a century ago (~1kite/km), and Peter Lynn worked on similar-sized yacht kites to go downwind in the open ocean at high altitude (>500m), but KiteShip developed far larger kites for 12m Cup yacht racing only flying low (~100m). Kite sports have similarly large ranges of Tether Factor highly independent of WS, from Kite-Fishing to ParaGliding.

Pierre is right about AWES scaling being a confusing subject, but that’s not my fault here in presenting it as clearly as an introductory AE lecture.

Inline image
New Forum Original Page-

Scaling by size