I have an aircraft engineering background, and there are some fundamental numbers that you use no matter what type of aircraft you have. They come from experience with the tried and true. This tradition isn't as apparent with wind turbines, so whenever I get a chance, I try to find a few "basic" facts. The gust yaw rate may be like that, but some of you are already thinking it's proportional to mill size, so I'd have to qualify the numbers if they are to be useful for any prop other than this exact one.
I've found some "rules of thumb" for tail size and length recently, and I want to put a bit of research into that, too, though they do work well.
Willib,
If you look in my diary, you will find my entry on RPM measurement. I'm currently using a bike speedometer. I chose one with nice Max and Avg speed memory features, really handy. The speedo is not visible in the photo above. I built a second, similar mount, so stay tuned, a photo of it will inevitably appear soon.
From Flux: "Fortunately it is speed related and the big machines are much slower in yaw and seem less troubled by these things than some of the smaller ones."
Imagine how hard it is for the professional guys, who have to design for gust GRADIENTS that are stronger on the blades going through the top of their arc, and weaker on the lower blades. A recent peek at the NREL design requirements for the large types of mills really put me in my place!
PS: My windmill is simple enough that no analysis on any topic should be so complicated that it takes more than a page. I will try to keep it simple!
