Thank You Pierre - no time to read a whole paper on related concepts and then try to guess how this ship propulsion idea is supposed to work. Iâll just leave it at the âpress-release breakthroughâ / âpublished-renderingâ stage, assume it will never be built, and if it is, that it will be abandoned as unworkable in some way. 
Here;s the latest EVTOL news = reminds me of Makani;s last flight:
[Second high-profile test flight crash rocks eVTOL industry (newatlas.com)](Second high-profile test flight crash rocks eVTOL industry
Latest ânewsâ on CoFlow Jet enhanced wings:
Coflow Jet CFJ-VTOL (concept design) (evtol.news)
And hereâs their co-flow website, advertising its âmillion fliesâ, same-as-the-rest, EVTOL concept for âurban mobilityâ designed, presumably, to get people to the airport faster! (like all the rest).
Home - coflowjet
On the one hand, this latest possible âProfessor Crackpotâ (?) is working with NASA etc. talking up a really heavy electric airplane for flying the near vacuum of Mars, at around 3000 feet altitude (even thinner air).
So the atmosphere in Mars has 0.00646 (only 6.46 thousandths!) of the air pressure on Earth. Thatâs by far less than 1% of the air thickness on Earth. If you consider the lower gravity on Mars, youâre dealing with about 1% of the ârequiredâ lift available on Earth.
Meanwhile, all they have are renderings and promises.
As Iâve pointed out in previous messages in this topic, IF they were serious, IF they really had something workable, WHY wouldnât they be winning STOL (short takeoff and landings) competitions NOW? It seems to me this would be the obvious place to prove what they have.
And before that, as Iâve also pointed out, what about RC models? If building a CoFlow Jet wing system for a mere Piper Cub is âtoo much workâ or âtoo hardâ or âtoo complicatedâ or âtoo expensiveâ for the good professor, why not build a prototype at RC scale?
This reminds me of AWE and âreplacing hardware with softwareâ - after 15 years, nobody has had time to write the software yet? To even have an AWE system working on a daily basis at RC model airplane scale? Why?
This âsyndromeâ never seems to end. Learned âprofessorsâ in their âivory towersâ talk of endless possibilities in aviation, but canât build even the simplest prototype to demonstrate their claims, while determined, enthusiastic individuals, most probably without even a college degree at all, build modified versions of Piper Cubs that win STOL competitions, leaving the good professor stewing in his endless renderings and outlandish(?) claims.
It is interesting to note if you go to the CoFlow.com website, they do mention the difficulty of even the basic concept of powering airplanes electrically (basically a flying battery pack, with no weight capacity left for passengers or cargo), but that doesnât stop them from combining (on paper only, of course) electric power, AND distributed propulsion (lots of small propellers) with their CoFlow jet concept.
This is one more instance (symptom) of âThe Professor Crackpot Syndromeâ: combining several new ideas together, but with the supposed focus on their one actual (supposedly, but not really) ânewâ idea, which serves to add just enough confusion and uncertainty about the whole combination to fool even the supposed âexpertsâ and decision-makers.
So you have the idea of âCoFlow Jetsâ to add to the lift capability of a wing. âAll-ya-gotta-do-isâ add slots, ducting, and compressors inside the wings to prove that your idea will work. But no, that would be too easy, right? You would âeasilyâ either prove, or disprove, your âtheoryâ that it is a good idea. But no, itâs the âdisproveâ part they seek to avoid.
How do they avoid disproving their theory? Add complication! Add more irrelevant details until the whole thing is suddenly way too complicated to ever build.
You COULD build an RC model, even electrically-powered.
You COULD build a Piper Cub style STOL airplane and win the existing competitions.
But no, that might put a quick end to your nonsense, since maybe you would NOT win the STOL competitions. Maybe your RC scale model would not really work so well. So they avoid that, and insteadâŠ
Talk about a difficult-to-build, very heavy, very expensive, full-size, passenger-carrying âflying batteryâ that would be believably too difficult to actually build, and require years of intensive âcertificationâ to ever be allowed to fly at all, let alone in âurban areasâ. That way, they NEVER have to PROVE any of what they are saying. This is âThe Professor Crackpot Wayâ: Make âthe storyâ so complicated that nobody could ever expect you to build one and run it.
And by the way, the whole âurbanâ excuse, is reminiscent of Professor Crackpotâs (often drag-based) vertical-axis wind turbines - always said to be âideal for urban environmentsâ since it âresponds to winds from any directionâ, and âspins in the slightest breeze!â Of course the implication is a wind energy systems at a low height, surrounded by buildings that block the real wind, or even at ground level in someoneâs back yard. This is where again, using trick words like âurbanâ, with all the political correctness and guilt trips that word alone entails, the promoters try to position their nonsense in such a way that nobody would dare question any of what they say, and since most people know nothing of wind energy anyway, being âresponsive to low windsâ and âturbulent windsâ from âany directionâ sounds great! It just makes no sense, but people not only âdonât knowâ, they âdonât know that they donât knowâ so they just âbelieveâ whatever nonsense is being promoted. âSounds great!â is what they think, and the good professor gets another round of funding!
Even more ridiculous, these CoFlow promoters are onto (talking about) flying one on freakinâ MARS!!! OK so let me get this straight, Professor CRACKPOT, you canât even build an RC model or a Piper Cub in the thick atmosphere of Earth, even using a gasoline-powered engine, but you TALK about flying an electric one on Mars, which would be literally 100 times as difficult as on Earth, or more when you consider the fact that Earthâs atmosphere supports being powered by a lightweight gasoline or jet fuel engine(s)!
They have renderings of a production model airplane weighing over a ton, and talk about its capabilities as though it actually exists (one more âsymptomâ of âthe syndromeâ), but they canât be bothered to build a demonstration powered by anything, at any scale, no matter how long the years roll on.
So anyway, like so many ideas, I love this one at first glance, but letâs see one working!!!
I think you may be wrong on this one @dougselsam. The compressor will increase the lift on MarsâŠ
Hi Tallak:
Iâm not seeing any fleshing out of your statement. What we call âLiftâ, treats air as an incompressible flow, and is relative to a certain ambient air pressure and density to even work. The vacuum above a wing is only effective relative to the remaining air pressure below the wing, which is what is actually lifting the wing, just as the relative air pressure is what lifts water in a drinking straw when you apply suction at the top to drink. In a vacuum, a drinking straw would not work.
Similarly, adding compressed air to blow over a wing in a near vacuum might be expected to push down on the wing rather than seeming to âpullâ up.
So, anyway, Iâm not sure what you mean by me being âwrongâ in expressing skepticism over the efficacy of a blown wing to somehow ârescueâ the concept of an electric airplane (a flying, heavy battery pack) on Mars. In aircraft design, light weight is the MAIN and most important design driver. This is multiplied by over two (2) orders of magnitude on Mars. So, if these bozos with their now-ancient concept of a blown wing, still barely even demonstrated in an atmosphere 180 times as thick as that of Mars, and still not being utilized even on Earth, have any confidence in this idea, Iâd like to know why.
Iâd feel sorry for any effort to combine super-heavy electric battery propulsion, AND distributed drive (many small propellers), AND the extra weight of ducting and âmini-compressorsâ, in what could only, legitimately, be described as a near perfect vacuum, equivalent to the nearly outer-space rarefied low density of air at 60 miles altitude here on Earth.
Sounds like more âall-ya-gotta-do-isâ thinking, which as we know from all the endless âpress-release breakthroughsâ, is endlessly celebrated, but seldom realized, forming the clickbait-oriented fake reality we find ourselves currently immersed in.
STOL contests may not be the only defining factor in aviation, but for any system purporting to generate so much extra lift, it would be the obvious starting point to prove their theories beyond any doubt - a starting place for establishing minimal credibility.
In fact, I could scarcely imagine developing such a theory and supposed âbreakthroughâ lift augmentation technology without ever trying it in a STOL competition, or at the very least, building prototypes, even at an RC scale, to prove how âgoodâ it âreally isâ. Anyone having a good way to augment lift to that degree would, in my mind, be inexorably drawn to building a STOL airplane, or even helping existing STOL competitors to incorporate such a system in their existing planes. As weâve noted here in this forum before, regarding the years of silence by most AWE efforts, we can often glean more information from what is NOT being done or said, than what IS done (or mostly just âsaidâ).
8 posts were merged into an existing topic: Slow Chat III
Hi Doug, please can you provide the link of the article?
The website:
Dr. Gecheng Zha seems to be the specialist in Co-Flow Jets.
Not impossible.
The air jets from the co-flow jets seem to have pushed the last comments out of the topic.
Letâs come back to it, for example with this website (which was already mentioned above), still under the leadership of Dr. Gecheng Zha:
Technical Characteristics
- CFJ Owl-01: the first CFJ eVTOL urban vehicle.
- Range: 356 km.
- Speed: 290 km/h.
- Four seats.
- Full electric distributed propulsion.
- Weight: 2122 Kg.
- Battery energy density: 300 Wh/kg.
- Low noise.
- High safety.
- High efficiency.
- Low operating cost.
See also the video on this website.