[boost] Re: Unit library

From: Andy Little (andy_at_[hidden])
Date: 2004-01-12 16:10:12

"Deane Yang" <deane_yang_at_[hidden]> wrote in message
news:btud2l$jvr$1_at_sea.gmane.org...
> Andy Little wrote:
> > "Deane Yang" <deane_yang_at_[hidden]> wrote in message
> > news:btt06j$68c$1_at_sea.gmane.org...

>but I use my units library
> for software that is really used and licensed commercially.
> But I guess you physicists don't like doing things that are too practical!

I'm not a 'proper'  phycisist, but have had to learn it ever since I started
bunking off school to fly model aeroplanes. I always needed a bit more
speed, a bit more duration etc. I had to learn it.

>
> Seriously, I really do want to know. In fact, could everybody
> involved in this discussion who has actually used a dimensions
> library describe some of the specific applications? I have described
> what I use mine for in some detail, but I realized that I don't
> know what others use theirs for. Please don't hesitate to give
> the gory technical description; some of us are fairly comfortable
> with physics.

It started from this:
http://www.servocomm.freeserve.co.uk/Windpower/windrotor1/uber_frame.htm
 I got fed up with all the unit conversions and had requests for input in
inches etc. The rotor is one part of the system:
http://www.servocomm.freeserve.co.uk/Windpower/uber_frame.htm
 The more complicated part is getting the power into useable form. The
voltage from the  p.m.g is proportional to windspeed, while power is a
higher order function of windspeed. Wind is very variable. I need a
converter with a reasonable range to do the job of getting the power into
(say) a battery. In very high winds there is so much power available that a
furling mechanism is required. All in all there are a huge number of
problems. One day I hope I can model the entire system, while making it easy
for the user to create a design from very few params. Yet another problem is
design of the p.m.g itself... they are usually home
made. Currently the only way to find how much power you will get is to build
one and test it!(The whole thing is very D.I.Y.) Not an ideal situation...
However to do most of this I will have to get into much more complicated
sims than I am doing (mostly in excel). The wind rotor modelling could be
much better. Tip vortices ...
The p.m.g is made from permanent magnets, and coils of wire. There are a lot
of variables involved in getting best performance from that ...if I could
model it, and display the results...

Anyway I guess this is way off-topic
If you want to discuss small wind systems... go here
http://www.egroups.com/list/awea-wind-home

regards
Andy Little