Slashdot Mirror
NASA Has a Way to Cut Your Flight Time in Half (bloomberg.com)
An anonymous reader shares a Bloomberg Businessweek article: For almost a half-century there's been a clear speed limit on most commercial air travel: 660 miles per hour, the rate at which a typical-size plane traveling at 30,000 feet breaks the sound barrier and creates a 30-mile-wide, continuous sonic boom. That may be changing. In August, NASA says, it will begin taking bids for construction of a demo model of a plane able to reduce the sonic boom to something like the hum you'd hear inside a Mercedes-Benz on the interstate. The agency's researchers say their design, a smaller-scale model of which was successfully tested in a wind tunnel at the end of June, should cut the six-hour flight time from New York to Los Angeles in half. NASA proposes spending $390 million over five years to build the demo plane and test it over populated areas. The first year of funding is included in President Trump's 2018 budget proposal. Over the next decade, growth in air transportation and distances flown "will drive the demand for broadly available faster air travel," says Peter Coen, project manager for NASA's commercial supersonic research team. "That's going to make it possible for companies to offer competitive products in the future." NASA plans to share the technology resulting from the tests with U.S. plane makers, meaning a head start for the likes of Lockheed Martin, General Dynamics, Boeing, and startups such as Boom Technology and billionaire Robert Bass's Aerion. [...] NASA is targeting a sound level of 60 to 65 A-weighted decibels (dBa), Coen says. That's about as loud as that luxury car on the highway or the background conversation in a busy restaurant. Iosifidis says that Lockheed's research shows the design can maintain that sound level at commercial size and his team's planned demo will be 94 feet long, have room for one pilot, fly as high as 55,000 feet, and run on one of the twin General Electric engines that power Boeing Co.'s F/A-18 fighter jet.
But.. the fuel cost is really high and when the oil price shot through the roof, there is no way commercial super sonic transport could become a success. Supersonic transports are coming back, this time as small 20 seater or smaller targeting the super rich. There was an Airbus concept a couple of years ago. Now an American trial balloon.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
I'm pretty sure I don't want busy restaurant background level noise going on continuously. That would suck. I don't even want quiet restaurant background noise going on continuously.
And I'm an American, but isn't it really time we started using metric for all things tech? Thirty miles is about 50km. It's just not that hard.
I'm also curious how much more fuel this uses than subsonic commercial airliners.
As a general rule of thumb, fuel consumption goes up as the square of the speed. Double the speed, and you quadruple the fuel consumption.
But there are a lot of other considerations. For instance, faster planes can fly higher, where air density is much lower, and jet engines can be designed to work better at high speeds and high altitudes, but with the tradeoff that they work worse during the low speed take-off and landing.
On the other side, big planes are much more efficient per passenger-mile than small planes. The Concorde had a narrow body, and just couldn't carry enough passengers to make it cost effective. But it is questionable if there is really a mass market for fast and expensive air travel. Would you pay an extra $2000 to shave 3 hours off a trans-Atlantic flight? I certainly would not. I'll just download an extra book to my Kindle.
I recently took a ~4 hour flight, and spent almost 6 in the airport tween TSA sloths, the cattle car of an airplane being loaded, delays on the runway, getting my luggage at baggage claim, and waiting for a fucking bus to go to the car rental place
Then to top it off, it doesnt matter how early or late my flight is, or where I am going, I always get there at either morning or afternoon rush hour
An interesting fact mentioned is the use of the engine from an F-18. Fighter jet engines aren't very fuel efficient, they are fast. (Not an aeronautical engineer, but) I have read that the reason commercial jet engines are so large is because they are fan jets. They suck in a huge amount of air and bypass the main engine. The more air you suck through the main engine, the more fuel you can burn and you go faster. The large bypass allows slow jet planes to cruise along at 500mph while sipping gas.
So with all that in mind, is the barrier to selling a lot of supersonic jet tickets really the sonic booms? The Concorde didn't go under because it was annoying too many transatlantic tanker crews with sonic booms. I may not be fully informed, but this seems like a dumb business plan if you are just trying to solve the audio problem.
An interesting alternative: It is NASA, they do work with the military on occasion. Perhaps this is a research project that can apply to supersonic military aircraft in an effort to make them more stealthy. If you are invisible to radar, but everybody hears you once you punch the throttle, you have wasted a lot of green on stealth technology. So, for maximum stealth, you need to fly slow. This type of tech would solve that, and I can see the military spending hundreds of million on R&D to solve that problem.
An F-18 engine is exactly the sort of engine I would test with if I planned on introducing this technology to next generation military aircraft.
HA! I just wasted some of your bandwidth with a frivolous sig!