Edward M. Greitzer | Subsonic Civil Transport Aircraft For A 2035 Time Frame

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  • เผยแพร่เมื่อ 11 พ.ย. 2024

ความคิดเห็น • 10

  • @sergiomartinez7469
    @sergiomartinez7469 5 ปีที่แล้ว

    Excellent ! .... Turbomachinery is my passion

  • @noelanish
    @noelanish 6 ปีที่แล้ว

    Aurora is now a Boeing company.

  • @seaplaneguy1
    @seaplaneguy1 6 ปีที่แล้ว

    I am so far beyond this nonsense....

    • @seaplaneguy1
      @seaplaneguy1 4 ปีที่แล้ว

      @@acbulgin2 Lots of ways to skin a cat. These ideas are not the best way. My tech is much better. It has boundary layer, power on lift (not in their tech), Active drag reduction, post stall control, roadability, 70 mph crash protection, and much more. Over 30 things are needed for the future of transit. None this nonsense found in the video will apply in a door to door future. At the core of the turbine flaw is the...core flow... Compression ratio and boundary layer become major issue, as he alludes to. Won't work. Notice all these airplane concepts are for LARGE transports. Why? The core and the boundary layer ratio. My tech can be down to 1 kw and still be efficient. Fast and slow is the future, not 0.8 Mach at 35,000 feet. Airliners are OBSOLETE...

    • @seaplaneguy1
      @seaplaneguy1 4 ปีที่แล้ว

      @@acbulgin2 Don't misunderstand, a turbine is great if you want to fly .06-0.9 Mach at 35,000 feet in a large bus...Airbus or Boeing type airplane. 15 hp/lb is amazing power density. The problem for the industry is not from large, but SMALL, just like the electronic industry. Mainframe computers vs laptop/smartphone. When lots of small engines can be more efficient than one large one due to the 3/2 law, distributed power is enabled. Central power no longer has an advantage over many small plants. The grid is based on many motors working together in a distributed power set up. When power varies outside the range one motor can run efficiently, a distributed power system can shut down motors to maintain system efficiency. If a motor can vary torque from 50-100% efficiently, for example, by having 10 motors you can get to 1/10th /2 or 5% of torque, not just 50%. Turbines are more like 85-100%, or shut it down. Turbines cannot be started quick enough to make such a thing work on a vehicle. Grid, sure, due to size and inertia, but not in vehicles. Size matters...

    • @seaplaneguy1
      @seaplaneguy1 4 ปีที่แล้ว

      @@acbulgin2 Thanks for the line. Yes, the article points out where the problems are. Higher turbine inlet also lead to more NO2. They are at or near that limit now. Going to 4200 F would be a NO2 generator and would not work. A closed gas cycle (using CO2?) would be needed with no N2.
      The point I am trying to make is that blown wing (like x-57, but different), boundary layer control and other means can lower drags by much more than the engine can be made more efficient.
      Key issue is that airports must be eliminated due to costs and lack of distributed transit.
      This requires high short duration power and low power efficiency in the cruise for slower flight speeds. Turbines force the airplane to fly fast and high.
      For example, if an airplane must fly at .8 Mach (528 mph) at 36,000 feet, what if it could fly at less than 1/2 that speed, or 264 mph? The increase in economy could be ~4 times. This is important for cargo.
      My flying semi truck uses this advantage to allow 5.6 mpg compared to .7 mpg (cruise, with average of climb and decent is more like 0.45 mpg) for a 737, or about 8 times less fuel with a cargo ratio of 55,000 lbs vs 40,000 for the 737. 5.6/0.7 x55/40=11 x better economy per lbs of cargo at 250 mph vs 528 mph. This makes the flying semi equal to a road semi at 300+mph when direct door to door is used. A pilot can be paid more than a truck driver, yet costs drop per mile. Truckers make 45 c/mile. A pilot can fly over 4 times what a trucker can drive per year and work only 1400 hrs vs 2000 hrs.
      The semi is then made into a drone with no pilot at 25,000 feet. Fuel costs are 11 times less than a 737 and pilot costs are only on the takeoff and landing (RC) to send off the truck and retrieve it, which can be 5-10% of normal pilot costs. Eventually it can be all automated.
      A turbine will not be able to compete unless a very new design is made that allows 30:1 (50:1 as shown in video) or more compression ratios (mine are 81:1) in micro power range with distributed power. A hybrid electric could be made, but is very heavy.

    • @seaplaneguy1
      @seaplaneguy1 4 ปีที่แล้ว

      @@acbulgin2 NASA did a study of what the optimum speed is for private transit. They claimed 160 mph is that speed.
      My point is that if you can drive door to door and not need airports by using roads as landing and takeoff places clear of cars at 25-70 mph depending on posted speed limit (optimum traffic speed), the need for large transports is largely gone. Uber taxi becomes faster and less fuel than what a fully loaded airliner can deliver. That target is 100 miles/gallon/passenger. My two place airplane (50% scale of 19 passenger airplane) can get 1 person at 100 mpg at 154-184 mph depending on configuration.

    • @seaplaneguy1
      @seaplaneguy1 4 ปีที่แล้ว

      @@acbulgin2 Trains failed due to the invention of the rubber tire which allows no track and any vehicle to run in any lane.
      Roads are very expensive. Taxes on a 4000 lb car should be 4 cent/mile. This is what they were in 1990's $$$ (about 2 cents/mile = 4 today) and have not changed since. Roads are funded via debt and income tax, which should not be allowed. Add in tires at 2 cent/mile and road related risks and damage not found in the air, of 1 cent/mile and the total is 4+2+1 = 7 cents/mile to drive on the road before fuel costs.
      My tech could fly you at 7 cent/mile fuel at over 250 mph at 12k feet. This is like flying fast for FREE fuel instead of paying the costs of road tax, tires and brakes, etc. for a vehicle that averages 40 mph at best, 25 in large cities.
      When people realize that they can fly for "free" fuel compared to driving, the traffic will go to the sky. Local roads are all that is needed. Interstate roads are not needed.
      This changes everything in transit, just like the rubber tire made trains obsolete.
      People want PRIVATE transit, not public that goes on some schedule. Time is money and public transit is very expensive in both time and cost of capital (roads/tracks and vehicles). These airplanes can also be made drones at 250-350 mph much easier than road bound AI cars.