The ludtitz set up incorporates a straight section with a huge bearawayplummet wrote: ↑Tue Dec 05, 2017 10:36 amWhat I find interesting about the luderitz trench is that its straight broadreach. Why? the fastest speeds are achieved with a arcing downwind run. The faster you go the further back the wind window shifts and the further you can point down wind. With a high aspect kite you can point even further down wind at speed.
What limits speed? Drag.joriws wrote: ↑Tue Dec 05, 2017 1:53 pmWhy do you omit most obvious speed limitation at higher range? Rider's body is a great drag source limiting speed. Rider drag => effectively like turning upwind in regards to kite => pushing kite to window edge => reducing power from kite. This is clearly visible in ice speed records (~120km/h) with very low friction. As with buggy with aerodynamics the record is ~130km/h.
Keep in mind that with 1g acceleration (which is a lot) your "flat body" terminal velocity in lower atmosphere is about 200km/h.
Yes indeed and Jorist is also right, drag of the rider is important on water and dominant on ice (like for skiers, square of the speed) ; in my above explanation drag of the kite is "hiden" in the L/D ratio for which we have some figures ; I do not neglect the body drag at all , I just say that even if we neglect it, we have a maximum unreachable speed limit of L/D times wind speed, basically due to 90 degree angle that the kite will have toward the rider direction;gbrungra wrote: ↑Wed Dec 06, 2017 6:11 amWhat limits speed? Drag.
Sources of drag:
1. Foil (hydro drag)
2. Rider+board (aero drag)
3. Lines (aero drag)
4. Kite (aero drag)
If liter on ice skates can go 130kph (70knts) and liter on hydrofoil can only go about 40 knots, then the difference can be attributed to the hydro drag of the foil, correct?
Unless I have the immediate opportunity to ride, I am ready to spend time behind my keyboard for any clarification request , if constructive
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