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voyagerB

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Everything posted by voyagerB

  1. Have answered your first question, I guess. Means that the FPPs rotate at a (reasonably constant) speed which is energy-efficient. One can imagine that the push prop will have variable blade settings. Low level ATC through V2V connectivity and GPS. Auto-piloting comes next. Vehicle autonomy is considered easier to implement in the 3D compared to the more complex '2D pane'. Energy efficiency is everything, particularly for battery power. The hope/expectations is for Next-Gen batteries with a much higher energy density. Notice the big pods. A high portion of the eVTOL's own weight will cons
  2. I assume they opted for FPPs for the sheer simplicity, low maintenance and low costs of them. Notice that the model (probably) features co-rotating blades (rather than contra-rotating). NASA found out that stacked coaxial co-rotators have a better efficiency contrary to what had been assumed until recently. Less noise too (which is a form of waste).
  3. Dunno. I just posted some of the promo material I found on the internet. I'll check... But IMO the more serious issue is that the TriFan only makes sense if it's reasonably point to point. But with those fans I don't to see the TriFan getting clearance to land close to one's destination. The TriFan will need to land at an airport. And that raises the question: why have such expensive VTOL capability?
  4. If you take the concept of a tri fan apart, slim down the parts and free up fan diameter for more efficient disk loading (front ones swivel to operate in fwd mode), you might end up with something like this. Lower CG will also benefit stability. You might even envisage a detachable cabin which constitutes a car if it is lowered onto a chassis...
  5. https://aerospace.honeywell.com/en/news-listing/2017/october/honeywell-to-power-groundbreaking-trifan-600 Honeywell's HTS900 engine is gonna power the TriFan.
  6. It's a nice design. I once did the numbers though, and came to a disc loading that's more than double that of an Osprey, making flying over and landing/taking off in the built environment virtually impossible.
  7. Don't be so quick to dismiss the whole eVTOL phenomena. Many projects are underway; some from reputed builders. And it is a particularly hot topic with the American Helicopter Society AHS. Below an overview of well-known eVTOL projects.
  8. I've been to that particular conference, what a coincidence. Here is an overview of all known eVTOL projects, the U.S. proudly leading.
  9. No, it won't. Besides the 'fact' that most experts think it will be easier to implement '3D auto-piloting' than '2D AP'.
  10. https://www.cnbc.com/2018/03/13/kitty-hawk-cora-larry-page-backed-firm-unveils-autonomous-flying-taxi.html
  11. It's why some seek a combination of rotorcraft and small aircraft. Throw the car into the equation, and you get something like this:
  12. Everything with eVTOLs stands or falls with the battery technology. If it's substantially better than today in let's say 3-4 years, I see eVTOLs take off so to speak big time. For now, range shortage can be compensated for by using hybrid drive, so, have a potent ICE onboard that can either provide necessary boost during takeoff, extend range and/or help to recharge the batteries. There might even be a way to combine a lightweight electric car and an eVTOL.
  13. Curious what the solid state battery technology might bring in 3-4 years... https://cleantechnica.com/2017/10/31/toyota-exec-solid-state-battery-tech-game-changer-evs-arent-backing-away-hydrogen-fuel-cell-vehicles/
  14. I totally agree! But I checked different sources. Original estimates for the period 2015-2024 have already been dialed down from 24K to 22K, mainly as a result of the crisis in oil and gas exploration. But I did not expect that the number of helicopters sold for passenger transport use is under 500, worldwide. I guess that new sales can feel flattered by the number of preused sales.
  15. Found this. Which means that the number of helicopters sold for passenger transport is less than 500 each year, worldwide.
  16. I read somewhere that it's in the neighborhood of 22,000 sold/ordered in the period 2015-2024. So, 2200 each year. Less than a quarter of that last number solely for the purpose of carrying people, private or corporate. But perhaps someone here has more accurate statistics...
  17. I tend to agree with you. The most astonishing example of winning over investors with a flawed idea (according to experts) is Lilium that received a $90 million infuse recently. See my earlier posting.
  18. That's the Volocopter recipe (German). The Passenger Drone (that's what it's called) is Swiss engineered and made, Peter Delco (interesting name) being its founder.
  19. So, how come German Lilium recently received 90 million USD from investors? Experts I talked to mentioned the same reason (too small thrusters) to make it fly for any interesting range, with enough batteries and people onboard. I calcaluated that the disk loading must be around 378 lb / ft2. 14 times as much as the Osprey's. Don't know about the downwash, but it must be one helluva screamer!
  20. New battery technology will be decisive, sure. Below a sort of checklist. IMO, there's terrain that can be gained on the conventional chopper. It's a debate or say prospect that bears similarities with that of the conventional gas-driven cars vs self-driving EVs.
  21. Chris, you wrote: "Since 550 ft. lbs./sec is equivalent to one horsepower"... Does that mean: 1 hp to lift one lb 550 ft up in the air per second? I am still in the subject of how to calculate the amount of hp or kW needed to lift a certain weight based upon the aircraft's disk loading (lb per ft2). I came across this: http://www.heli-chair.com/aerodynamics_101.html Where an "empiracly defined formula to calculate the thrust loading (after McCormick)" was introduced. TL [lb/hp]= 8.6859 * PL. Thrust loading is defined as lb per hp = 8.6859 x disk loading (power / disk area)... It speci
  22. Erh... no. Yeah, that is the PAL-V's party piece. If it is patented (and I think it has been) it can also be found at the U.S. patent office. Or google for PAL-V foldable rotary wing. Or so.
  23. Yeah, as a Dutchman I am familiar with those guys. As a matter of fact, I visited them once. IMO, they're presenting the first truly viable flying car. It's a three-wheeler for road legality reasons (not that different in the U.S.). It uses a push prop. The overhead rotorblades are meant for use as an autogyro. So, if there's a power fauiure, it autorotates towards the ground. The setback is its price of $450,000 and the fact that you always need a runway. The trend nowadays is VTOL.
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