please understand, i have no desire to be a "wet blanket" about your design idea,
and have no problems with alternative designs, however
i would direct you to do a google search for this book
Dynamo-Electric Machinery
a manual for student of electrotechnics
by silvanus p. thompson
various editions going back to about 1885 or so
in that book you will quickly learn that there is really nothing new in alternator/generator design, apart from materials used and modern design and engineering techniques that reduce the amount of ancillary materials used and in the process also make things that
are arguably less visually appealing.
in the book you will find sketchs/drawings/plates of all manner of generators and alternators, from the common radial designs to all sorts of axial designs, with steel/iron/laminate and "yes" even the aircore design that is so much in vogue with diy home built wind generators today.
the point being, the air core that is used today, that has become so popular was based on
existing designs that were successful over 100 years ago, but fell out of favor mainly because 99.99% of all alternators/generators were driven by water (wheels or turbines), steam engines, or what they refer to as oil engines (diesel and gas today). all such power sources are of more or less constant speed and stable power, unlike wind power.
had there been more need for wind power at the time, beit because petroleum oil had not
become widely available, or coal not available for steam production, water power limited
we might have today some really massive or at least widely used aircore alternators all over the place. Wind would have been more viable in a world where cheap fuels were not available.
basically no different that the cyclic interest in wind power over the years, before rural electrification here in the US, folks wanting power bought windgens, after the power lines made it to the farm they fell out of favor. fast forward to the 70's and the oil embargo
we had another spur of interest, and now in the new millenium there is another surge in interest.
at least this go round some very practical folks like hugh piggot, decided to take
another hard look at what had been done in the past, and what might work better today
given the new neo magnets that were not available in the 30's or 70's. Apparently he either rediscovered the 100 year old aircores, or learned of them in his research. Either way he from previous experience working with iron cores, radial and axial, likely had
and "aha" moment and could see that the air core removed some if not most of the problems associated with iron core alternators when used with a variable power source such as wind.
you seem to have much interest in building wind generators, for your local people and family to learn, and benefit from that power. therefore, i would strongly suggest
taking a hard look at the history of the alternator/generator and particularly how either
has been used with wind power.
there really is no reason to totally reinvent the wheel, far better to take someone else's
wheel design and work to improve it or alter it in such a way that works best for your application.
bottom line, if you are going to spend money on magnets and copper wire, one is best advised to use those resources in the most practical and advantageous way possible.
best of luck with your project
bob g