Project Sol'R

http://www.projetsolr.info/

This group in France will be trying to fly the English Channel, they are in flight test mode at this point it looks like.  They flew their ship (Nephelios) for up to an hour so far.

The ship is 22 meters long, 5.5 meters in diameter.  Cruise expected 40 km/h  at 2.4 kW

They went with three props for propulsion, with a pretty minimilistic control seat.  I went to the French site to their blog and did the translation of the page using the right click of the mouse option:

http://www.microsofttranslator.com/BV.aspx?ref=IE8Activity&a=http%3A%2F%2Fwww.projetsolr.info%2F

This might be a short clip of it flying:

http://www.dailymotion.com/video/xcuzdz_nephelios_tech

If someone can post the video direct that might be better....

<<<Cruise expected 40 km/h  at 2.4 kW>>>
I know it's hard to get the right info from a website but the 2.4 kilowatt stat is misleading. This is a VERY important number because it is so challenging to get enough electrical power in an UL airship to navigait the winds.  I must open it to debate since it can cause heartbreak to erstwhile airship designers when they operate with faulty information.

I've looked into solar PV cells and found that flexy modules are relatively inefficient, about 6 to 8%, [Uni Solar brand, specifically] and modules of the size in the photo can only put out 100 watts max and they have maybe a dozen, so they'd get 1200 watts if the sun were shining perpendicular to all of them, which it can't, so they're getting about 60% output due to modules being curved over the top of the envelope and not all facing the sun.

So, they're probably getting about half a kilowatt of power, 600 watts and I doubt they can go 40 km/hr [25 mph] on that!

The misunderstanding might be because the overly optimistic 2.4 kw spec could refer to max battery output at takeoff  when fully charged. Very much different from assuming the solar power output is 2.4 constant kw's which I don't think is possible unless they're receiving some sorta multimillion dollar research grade modules from Siemens!!. 

I noticed a lot of advertising on the ship. How come it's ok for them, but Marvin got flack?
 I presume the rudders and elevators are movable, but the controls did not show.
You wonder why three props are necessary. His are movable like Rousson's, there's a lot of this ship similar to Rousson's.
Once away from the ground, I would think rudder and elevator control would be all that is necessary, directional props are just more weight and complications, and drag. Put plenty of power to an articulated prop on the tail, that's what I would do.

They may have more power than 600 watts. They have a good number of panels. As for advertising, they aren't in America, so the laws may be different. 

It's great to speculate on what their control philosophy is. Here's my guess. Being a sad, saggy and swelling blimp, it would normally need a ballonet to keep it firm and also to relieve some internal pressure when superheating and keep it from popping. All in favor of a dirigible, say "aye." But they don't want the complication of installing a ballonet inside their lift bag so they go with up/down propellers to compensate for the changing buoyancy of an uncompensated bag.

So then they decide to use the two up/downs as triple duty props. They make the individual motors capable of differential speed so they can drive one side more than the other, or maybe even reverse one side, who knows, and firmly turn the head of the craft without enough speed for steerageway by fin movement in the slipstream. 

And the third function of the props is simple forward motion, achieved by pointing both straight ahead and running them at identical rpm's.

So the extra weight, compared to a single pan-and-tilt prop at the stern, pays off in terms of versatility. 

I don't like their philosophy however. I think it simpler, safer and more elegant to go hybrid HTA/LTA and use aerodynamics to vary the lift rather than pointing propellers at the sky or ground.   Yuch..

All you gotta do is ignore the lighter weight of frameless envelopes and learn how to make a new dirigible. Also ignore the stinking complex Zeppelin frames. They were a century ago, people! Think lenticular umbrella frames. C'mon, French college boys, it's not that hard, think UP and you'll GO up. Lenticular rules! [if you let it]

About advertising, they are a non profit college and use sponsors up the yinyang  to pay for the research. Since they don't have a HUGE ad sign on the side, maybe they are seen as mere acknowledgements of helpers. You know they're not MAKINg money, just paying for expenses. 

Maybe we could get away with that ourselves?????????????

Whose products do we want, first of all???? Then let's ask them for donations.

I have contact info on from one of the team members that is willing to answer any questions we might have on their ship.

Maybe we should either put together a list, or invite him onto our conference if he has some time?

List of questions:
 
Envelope material and why it was selected.
What height (service ceiling) is the ship designed to fly to.
Ballonets how many and where located, unless it is as Nav thinks without.
Motors, how much hp (CV's) on each. Main uses. all three at once or just tail for main.
Water anchor?
Have more but have to go....

Ballonets can be seen inside the craft in some of the pictures. There appear to be two, one fore and one aft. 

Yep, those shadows on the envelope are probably ballonets. I didn't think the Solr had em because I saw no way of controlling them when airborne and I guess they adjust them on the ground and leave em that way for the short flight durations they are stuck with.

hmmm. Doesn't seem worth it from here. Woulda been simpler to move the gondola back and forth for trim. They don't hafta go over two hundred feet high so they don't have to worry about lift gas swelling and shrinking. Maybe they are to deal with superheating, I don't know enough about airship gas dynamics to judge why they bother. I just don't like'm.