On Fri, Sep 16, 2011 at 08:30:24AM +0200, Onno Meyer wrote: >that is certainly the case for sailing anywhere close to the >wind. But some early balloons had sails -- was that just a >misunderstanding of the physics?
Yes. >With time, the craft would probably accelerate to the speed >of the wind, and it would be at rest relative to the air >around it, if the speed and direction of the wind is >constant. What happens when there are gusts? The velocity vector will slowly (the heavier the craft, the more slowly; the higher its cross-sectional area, the more quickly) come to match the wind vector. It is likely to change facing while it's accelerating. Picture it as a keel-less boat, or a flat-bottomed model sliding across an icy pond. A vessel drifting in a single fluid will go where that fluid takes it. On Fri, Sep 16, 2011 at 10:48:05AM +0200, Nils Jan Richter wrote: >- There is a precedent for sailing "in just one liquid": interplanetary solar >sails. Radiation pressure doesn't work just like aerodynamic pressure. R _______________________________________________ GurpsNet-L mailing list <[email protected]> http://mail.sjgames.com/mailman/listinfo/gurpsnet-l
