slowrotor,
I mention the weight because you must have a tight weight budget to maintain a disk loading of 1.0 Put all the weight you want to into your blades, but then you have to put more into the head to restrain the CF, and then the shaft to support the whole thing, etc.
As an example, the Djinn you mention had very very heavy blades because they had to withstand the tip thrust. The aircraft had a 240 Horse Power engine, so it lifted about 7 lb/hp, about four times worse than the aircraft you envision. Its disk loading was 1.7, even with those strong blades.
I suggest that you start a weight breakdown of the machine, and assign some numbers, then compare to that of other machines, using parametrics (lbs/hp, etc.) to try to put some credibility to your numbers.
The most supreme difficulty in ultra lights and man powered aircraft is to achieve adequate strength/safety while maintaining weight discipline. This is especially true of a whirling blade that must prevent aeroelastic instability while operating in a wide rpm band. Most successful solutions use more engine power, lower radius and higher disk loading because then the structural problems are more easily met.
None of this is an attempt to damp your enthusiasm, good luck!
Last edited by NickLappos; 7th Aug 2003 at 12:17.