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From: John Fields on 11 Aug 2010 11:22 JB, I posted the following a while back, but haven't seen a reply. Maybe I missed it or maybe you missed my post? "While I've got your attention: Maybe it's just me but, with no rancor intended, something seems to be amiss with a couple of the the videos on your website. 1. In the first video, DDW.MOV, According to the weathervane on the truck, the blackbird is heading into the wind and, according to the direction of rotation of its rotor and the pitch of its blades, that's confirmed. Now, since the vehicle is at a standing start, there's a headwind, and there's not enough drag being generated to push it backwards, (obviously) there's no torque from the wheels' axle to drive the rotor, so the rotor _must_ be acting like a turbine and, through gearing, transferring the torque the wind is generating on the rotor shaft to the axle, which drives the wheels which push the vehicle into the wind. That's contrary to your contention that, for a downwind machine: "the rotor does not provide the torque to turn the wheels (ever)." So it seems that even though the video is titled: "DDW.MOV", it's not really a downwind (wind at my back) machine, but an upwind (wind in my face) one, right? 2. In "Record Day July 2-3 2010" the rotor turns in the same direction as in "DWW.MOV", (CCW, looking at the driver head-on) except at the end, where it's turning backwards. Also, the streamer which shows the wind to be coming from the rear for a couple of seconds at the beginning of the video is missing for the rest of it. ??? :-)" --- JF
From: John Doe on 11 Aug 2010 15:25
John Fields <jfields austininstruments.com> wrote: > JB, > > I posted the following a while back, but haven't seen a reply. > > Maybe I missed it or maybe you missed my post? They do not do UseNet, Jiffy, they got to be "faster than the wind" thread by searching on Google. You might be able to get their attention in a new thread by putting "DDWFTTW" or "faster than the wind" in the subject line. -- > > > > "While I've got your attention: Maybe it's just me but, with no rancor > intended, something seems to be amiss with a couple of the the videos > on your website. > > 1. In the first video, DDW.MOV, According to the weathervane on the > truck, the blackbird is heading into the wind and, according to the > direction of rotation of its rotor and the pitch of its blades, that's > confirmed. > > Now, since the vehicle is at a standing start, there's a headwind, and > there's not enough drag being generated to push it backwards, > (obviously) there's no torque from the wheels' axle to drive the > rotor, so the rotor _must_ be acting like a turbine and, through > gearing, transferring the torque the wind is generating on the rotor > shaft to the axle, which drives the wheels which push the vehicle into > the wind. > > That's contrary to your contention that, for a downwind machine: > > "the rotor does not provide the torque to turn the wheels (ever)." > > So it seems that even though the video is titled: "DDW.MOV", it's not > really a downwind (wind at my back) machine, but an upwind (wind in my > face) one, right? > > > 2. In "Record Day July 2-3 2010" the rotor turns in the same direction > as in "DWW.MOV", (CCW, looking at the driver head-on) except at the > end, where it's turning backwards. > > Also, the streamer which shows the wind to be coming from the rear for > a couple of seconds at the beginning of the video is missing for the > rest of it. > > ??? :-)" > > > --- > JF > |