Fri Oct 09, 2015 10:03 am
The motor technology is already here, you can buy this stuff off the shelf. A custom (Cessna 180) size motor is easily do-able on a special order basis... the overall design, materials, and way to build it is already in use. It will be a long time before 300 pounds of battery will provide the same amount of power-hours as 300 pounds of gasoline. It's coming, and they're working on it as fast as they can, but it is not "just around the corner" like Popular Mechanics always says.
Some sort of Nobel-genius chemical fuel cell that extracts most all of the energy out of Hydrogen, or some little terrorist-proof, sealed, crash-proof, eco-disaster-proof suitcase nuke electric generator is also out there in the "someday soon" area.
The near-term things that may actually make a significant improvement are things like better technology car engines. Ben Haas' V8 project is a great start. The reason for this is that automobile fuel efficiency has doubled or tripled in the last 75 years, mostly because of advances in fuel delivery and ignition (and little black boxes that run the fuel and spark). We've had the same basic poppet valve, round piston, Otto cycle engine technology in cars for a long time, not HUGE changes in the basic design. And yet the amount of usable power, and the relative efficiency, have gone way up.
Today's high-end Corvette makes 2 or 3 times the power, and gets 2 or 3 times the gas mileage as the first Corvette. While making a small fraction of the pollution/greenhouse/carbon footprint stuff. By contrast, the power, torque, fuel burn, and emissions on an airplane built in the same year as the Corvette came out... and the engine on an airplane today... is close to the same. Of course this is because of certification cost, liability, huge lawsuits that should not have happened, shrinking aircraft market, etc. etc. But the fact remains that once you get the obvious details sorted out (torque and power band shifted down to prop RPM's, allowing for higher duty cycle in aircraft use), a modern automobile engine similar to today's Corvette motor would represent a huge jump in performance and economy.
This doesn't mean I'm not looking forward to an electric bush plane that can survive and prosper in the Alaskan Interior. It means that while we are waiting for that magic battery or pocket nuke reactor... we should be doing what we can do with today's tech.
In Austraila, a busy glider club installed a "crate motor" small block aluminum Chevy V8 in a Pawnee that they had been using as a towplane. They went through all the headaches of government approval (exp/restricted/test case), and figured out the cooling system, and all the other hard work. After all the effort, in a couple or three years they had saved enough money in maintenance and fuel to cover the cost to purchase a brand new European training glider ($100K). And make no mistake, glider towplane engines have a harder life than bush plane engines.
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