Reaction Engines plan Mach 5 Airliner 221
What is? writes "A British company has designed an eco-friendly airliner that could make a trip from London to Sydney in under five hours. Reaction
Engines has received funding from the
European
Space Agency to design the plane as part of the
Long-Term
Advanced Propulsion Concepts and Technologies project. The
A2
airliner would be capable of carrying 300 passengers at speeds of up to Mach
5."
Nothing New (Score:5, Interesting)
Noise and price issues? (Score:5, Interesting)
The issues boiled down to two things that no amount of tech could alleviate: Noise issues (property owners near the airports got highly vocal about having to replace cracked windows from the occasional sonic booms), and price ($25k 1st class from NYC to Paris? And now you get to suffer the indignities of airport security too? Sounds like a masochist's dream come true...)
Unless/until they solve at least those two issues (in spite of public pronouncement, it doesn't look like they have IMHO - yet), they're going to have a hard time with it's initial public image, fuel economy be damned.
Sure the economics of volume may drop the price, and sure the noise problem can be solved through strict pilot discipline (e.g. no cracking the sound barrier until you're x miles away and at y altitude), but that won't change public perception that Concorde planted firmly in the public mind back during the 1970's).
OTOH, the tech is cool, and I can see a very solid use for it for trans-pacific passengers... Seattle to Tokyo in 3 hours instead of 12? Frickin' awesome...
Re:Oh, won't somebody please think of the math (Score:5, Interesting)
I just don't think there is a commercial viability for supersonic flight. The need to decrease flight times from 20 hours to 5 hours is just not enough of an incentive to cover all the associated investments and pitfalls of implementation.
Re:Oh, won't somebody please think of the math (Score:3, Interesting)
I think the objective is to cruise in very rarified or no atmosphere while flights like the concorde cruised @ 18kms
this would be close to 70-80 kms or near the karman line. The dynamics would be vastly different.
the engines would have to be hybrid between a rocket engine and ram assisted engine rarified and atmospheric operation.
Although i can still see a problem in "reentry" hopefully they figure out a way to slow down and somehow expand the
wing area to sustain low speed flights.
Technical risks are high but it is possible.
-Sundara
Thunderbirds are go! (Score:4, Interesting)
Re:Oh, won't somebody please think of the math (Score:3, Interesting)
You joke, but I've often considered the idea of creating super-sonic mass-transit systems between cities. The idea that I visualize in my head is having a vacuum-sealed tube through which magnetically driven cars pass. Each mag-car would act as a ferry for one or more conventional vehicle. You'd drive your car into the station, drive onto the open mag-car platform, the mag-car would be sealed and pressurized, then moved into the launch queue. When your turn comes up, the mag-car moved through an airlock into the transit tube. The tube is kept in a state of low-pressure (perhaps even a near-vacuum) to allow the cars to move at high speeds with lower energy expenditures.
As soon as you're through the airlock and into the transit tube, the mag-car is driven on the magnetic rails to high speeds. You are blasted to your destination in as little as a few minutes to an hour. When you arrive, the mag-car slows, moves into an airlock, exits the tube, unseals, and you are free to drive your vehicle off the platform. The platform is then replenished with air tanks and sent back with a new passenger from whence it came.
Rather than having every city connect to every city, large cities would be connected to the nearest large city. Which would have commuters changing over from tube to tube at each city in order to reach farther cities. When they reach the city nearest their destination, they exit the station and drive the remainder of the distance. Total travel time for even the longest car trip would be cut by hours if not days.
That being said, it's just a sci-fi dream. It's possible, but there are some very real engineering and market forces working against such a project.
British Technology Never Flies (Score:5, Interesting)
The last major triumphs of British engineering to actually get built were Concorde and the Advanced Gas-cooled Reactors.
Ever since then the can't-do-won't-do attitude of Britain's "financial service economy" curtails any great technological projects. The only things that get built are science projects, with meager government funding.
Reaction Engines/Bristol Spaceplanes have some very interesting engine designs like SABRE. These are the people who designed the RB545 for Hotol (another great British triumph of procrastination over achievement).
Mark my words, this will sit firmly on the drawing board and will probably be reinvented in 20-30 years by the Chinese. The American's won't have it since they didn't invent it.
It sucks to be British unless you're in Banking or Insurance. Still, mustn't grumble. At least we're not French or German or foreign. Time for a nice cup of tea and a sit down.
Re:Oh, won't somebody please think of the math (Score:5, Interesting)
Your point about electric cars I don't really get. Sure you have a longer tailpipe with an electric car, but if your thermal efficiency and CO2 or whatever pollutant you care about per mile is less, you are still winning. There are other technical challenges for electric cars, and a lot of people might not see that you have to look at the bigger picture, but even when you do EVs look pretty good.
reference on EVs here [evworld.com]
and yes I recognize that is an EV advocacy site, but their point is correct. IC engines have a thermal efficiency of about 15% or less. It's not hard to beat that with a stationary plant.
Now, about the present article - I'd like to see some analyses that say that you can actually fly a supersonic plane a good distance on hydrogen, and how the hell you think you can make that economical.
Re:Noise and price issues? (Score:3, Interesting)
So noise becomes a moving target, driven forward by your own advances to try to reach it.
This is discussed in detail in Erik M. Conway's terrific book, High Speed Dreams [amazon.com].
Re:Use Both Traditional and Ramjet (Score:2, Interesting)
Re:Use Both Traditional and Ramjet (Score:4, Interesting)
Over some 20 years, I met one, count 'em one candidate who correctly coded a Shell sort without blinking in an interview.
My question is basic, "Code a routine to sort a set of objects of any type of your chosing, based on a means of ordering them (comparison function). Use the language of your choice. The routine should be correct, and you be able to describe it's worst-case performance in O(n) notation. It need not be the most effective way of doing it."
Unfortunately, the candidate above made the fatal interview mistake of expounding on his personal school project "FTP server with dynamically loadable file-type handlers, based on requested file extensions" (to dynamically generate content based on extension), as a "servlet-supporting FTP server" to a different interviewer -- with a marketing backround -- who, for some reason, was trying to conduct a technical interview, when he should have been getting a feel for the candidates business sense.
This other interviewer dismissed the candidate as a fraud because "everyone knows" that web servers use servlets and ftp servers "don't".
Sadly, we had a policy where every interviewer had to "green light" a candidate for them to be hired.
And people wonder why so much software is crap.