Slashdot Mirror
Reaction Engines plan Mach 5 Airliner
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."
Terrorists can't threaten a country's freedom and democracy. Only lawmakers and voters can do that.
I've seen more computer generated designs for supersonic passenger aircraft than I can count.
Is this going to be a real commercial jet, or just another cock tease?
Lots of people have websites with cool drawings of fast planes. I scanned the material on their site and didn't see anything concerning a flux capacitor, so my cynicism is slightly abated.
I'd love to see how they can make an "eco-friendly" airliner that goes Mach 5. There are some really basic laws of aero and thermo dynamics that put the kibosh on most of these schemes. Look at the Concorde, XB-70, SR-71, for examples of how difficult and expensive it is to design, test, and operate anything going Mach 2 to Mach 3.3. And the problems just go up from there, often by squares and cubes.
Funny how they write about a Mach 5 airliner precisely when Slashdot crawls down to something like Mach 5e-55.
Terrorists can't threaten a country's freedom and democracy. Only lawmakers and voters can do that.
..they're buying the old Concorde airframes and launching them from the US Navy's new railgun?
for a nice crater.
MSBPodcast.com The opinions expressed here are my own. If you don't like 'em... Think up your own stuff.
Does that include the monkey and toddler hiding in the trunk?
First, those look like low-bypass engines (yes, I know they are "normal" jet engines), which means very high exhaust velocities. The small wing also means high wing loading and high takeoff velocities. Those two facts seem to suggest a very loud plane which might run afoul of EU regs.
:(
Second, I can't help but think that fuel costs will kill this idea. GIven rising energy prices (and no large-scale miracle hydrogen factories on the horizon), the fuel costs will tend to track oil and nat gas prices. Even "free" wind/solar power won't help because a hydrogen factory would need to pay a competitive price for energy, which will be tied to the rising cost of fossil fuels and the rising global demand for energy.
That said, I'd love to fly in this thing even though the artists sketch shows a lack of windows due to heat issues
Two wrongs don't make a right, but three lefts do.
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...
Quo usque tandem abutere, Nimbus, patientia nostra?
Good, now we'll finally use those little barf-bags on the back of airline passenger seats.
A British company has designed an eco-friendly airliner that could make a trip from London to Sydney in under five hours.
How droll. Soon, you will be able to travel from London to Sydney in less time than it takes to negotiate security at the airport. ^_^
____
~ |rip/\/\aster /\/\onkey
You can (essentially) only go supersonic over the oceans, so you need routes where you can actually use all that power, say New York to Europe or LA to the Pacific rim. Next, a ticket on this beast will cost slightly less than an average working stiff's annual mortgage payments. So we need to find 300 self-important assholes who are 1) richer than they are smart 2) in too big of a hurry to spend twice as much time crossing the ocean at 1/10th the price. And of course this model only works if there's regular service, never mind the fact that you only sold 4 tickets for Wednesday's LA to Shanghai run. There were how many planes in the Concorde fleet?? There is ZERO economic chance that this will ever happen.
No folly is more costly than the folly of intolerant idealism. - Winston Churchill
It looks like the plane Fireflash in one of the Thunderbird's shows. Okay, the engines are under the wings and not on the tail, but that's about it.
Popular Science wrote an article about this plane: Article
Yeah, it's a dual-mode engine. If you do a little research on them, you'll probably find that aerospace designers discounted such designs a long time ago. The problem they ran into was that rocket craft spend so little time in the atmosphere that the extra weight and complexity incurred through dual-mode operation ends up gaining very little over a BDB. (Big Dumb Booster)
The only time they really make sense is for nuclear engines. In the case of nuclear, you can use anything that can be heated and exhausted as fuel. This leads to three options that can be used to power a Nuclear Thermal Rocket:
1. Pass air through the reactor, heating it up and using it as rocket exhaust. This is relatively low thrust and would only be useful in combination with another booster or to maintain velocity in the atmosphere.
2. Pass air through the reactor, heating it up and using it as rocket exhaust. As the air exits the engine, add hydrogen fuel for a second reaction. This greatly improves thrust at the cost of fuel efficiency. Perfect for initial takeoff.
3. Pass a stored, lightweight material like hydrogen through the reactor, heating it up and using it as rocket exhaust. Thrust is good in this mode, but not great. Depending on the design of the craft, this could be used 100% of the time or while in space.
Creating such "Tri-Mode" engines is reasonably straightforward and has been done. (e.g. The Triton Nuclear Engine.) I'll leave it as an exercise to the reader to understand why they're not already in use.
Javascript + Nintendo DSi = DSiCade
Actually, the hole in the ozone layer is caused by CFCs, or chlorofluro compounds, and is currently shrinking.
Quis custodiet ipsos custodes?
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.
Stick Men
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.
In Liberty, Rene