Re:Faster than the Wind - Downwind

Don't we have some iceboaters on the list? I understand that they routinely go faster than the wind, even off the wind. Alfred Poor 1973 Tartan 34C #288 "Jambalaya"

Hey people, this craft is not on any kind of reach but directly in the direction of the wind. The apparent wind is 0 degrees. http://youtu.be/XQRW1yuYLnc Here is an explination that I can't follow at all. http://blogs.discovermagazine.com/sciencenotfiction/2010/06/10/impossible-seeming-wind-vehicles-are-quite-real—and-might-one-day-produce-abundant-energy/<http://blogs.discovermagazine.com/sciencenotfiction/2010/06/10/impossible-seeming-wind-vehicles-are-quite-real%E2%80%94and-might-one-day-produce-abundant-energy/> The idea seems to be that the wind pushes the vehicle to wind speed and the wheels drive the propeller which pulls the vehicle to above wind speed. Nothing like an ice boat or any other sailboat going faster than the wind at some angle. There is no angle. I am unclear if I believe this. I don't fully understand where the energy is coming from once the thing reaches wind speed. Allen <http://blogs.discovermagazine.com/sciencenotfiction/2010/06/10/impossible-seeming-wind-vehicles-are-quite-real%E2%80%94and-might-one-day-produce-abundant-energy/> On Fri, Jul 30, 2010 at 2:07 PM, Alfred Poor <ap… [at] bellatlantic.net> wrote: > > > Don’t we have some iceboaters on the list? I understand that they > routinely go faster than the wind, even off the wind. > > > > Alfred Poor > > 1973 Tartan 34C #288 “Jambalaya” > > > > >

OK I stand corrected. The momentum of the wheels (latent or kinetic energy) drives the prop which bites into the air to create acceleration above and beyond wind speed. That is the prop allows the machine to move through the air based on prop (fluid?) dynamics. Friction is the limiting force in the system hence a max speed is reached where the frictional forces probably equal the latent or kinetic energy of the wheels and total resistance of the vehicle against the air. Pretty cool stuff. At least that's how I understand it with my grade 9 physics...its been a long time so I may be completely wrong here........:) Theoretically its all still consistent with Einstein's first principles (that was university physics)..we had a really good prof in those years and people actually stayed after period to let him finish the lecture each time. Its amazing the effect of a good teacher.. Sailing content. Nothing like a mentor to look up too and learn from. aka like this list..and others Many thanks /ch

Alfred Poor wrote: > > > Don't we have some iceboaters on the list? I understand that they > routinely go faster than the wind, even off the wind. > Tacking downwind, yes. But to slow down; you head dead downwind. Then, friction limits you to true wind speed minus drag. Chris Campbell > > >