This article is typical of reportage on supersonic transports. The explanation of shock waves is terrible (subsonic aircraft compress air in front and reduce density behind as well), and the focus is on the boom, which ignores the cost elephant in the room, which is wave drag, which reduces range below the vital trans-Pacific market, and puts ticket prices through the roof.
12 thoughts on ““Son Of Concorde””
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Eh, I think you’re being a bit too picky; I’ve never seen a good nontechnical explanation of a supersonic shock wave (and no newspaper is going to publish a couple of chapters of, say, Anderson’s or Emanuel’s compressible flow books), so I’m willing to cut them some slack. And the popular press always focuses on the boom because that’s the elephant in the room for overland flight – say, NY-to-Tokyo, or LA-to-London.
I haven’t done the math on supersonic transports because they are of no interest to me, but is the wave drag really more important than the induced drag? I would expect SST induced drag to totally suck (pun partially intended) because in the classic parabolic drag polar, induced drag is inversely proportional to aspect ratio and Oswald’s efficiency factor, both of which are small for the typical SST platform.
is the wave drag really more important than the induced drag?
It is, actually, yeah.
I would expect SST induced drag to totally suck (pun partially intended) because in the classic parabolic drag polar, induced drag is inversely proportional to aspect ratio and Oswald’s efficiency factor, both of which are small for the typical SST platform.
That’s why you don’t want to use a typical SST platform, which is why, with such stultified thinking, it will always remain a niche market at best.
If you can get rid of the delta wing, you can put the wing tips outside the mach cone, and induced drag is essentially non-existent. 🙂
I disagree about SST remaining a niche. IMHO, VR telepresence is going to eliminate pretty much all demand for travel on Earth which doesn’t require someone to get from A to B ASAP. Fifty years from now, there’ll probably be electric vehicles for short-distance travel, and hypersonic aircraft and rockets for the few who have to travel long distances, or want to get off-planet.
I’m not sure I fully agree, but I do agree quite a bit. In fact, I think VR and other telecommunication devices will decrease the need for office space and daily commutes.
Still, there are jobs that require full presence to get the work done.
I was kind of wondering where they would get the engines. Then I read it was supposed to seat 50 passengers. Even then need to scale up the X-2 Shinshin engine. The Olympus used in the Concorde had like over 3x the thrust for 128 passengers.
Hey Rand, what do you think supersonic airships, powered by microwaves? The microwaves could be from an SPS, or LSP. The supersonic airship would have no fuel tanks. It would need a rectenna large enough to power the supersonic airship. I read about supersonic airship in a book called The Future of Flight. It was written by Dean Ing, and Leik Myrabo.
I remember when Leik presented that at Princeton in 1981. I like Leik, but c’mon.
Ok, I was going to say that the reason that flying on the Concorde was expensive, was because of the price of fuel, and the plane could only hold about 100 passengers. But I just read on Reason, that the FAA banned SST, from flying over land back in the 1970s. I didn’t know about that. I do think that research into beamed propulsion should be done. Perhaps as prizes.
Elon Musk plans to build a colony on Mars, and while you could do it with chemical rockets, it would be best to use something like VASIMR.
The articles states that their test vehicle produced a shock wave 30% smaller than an equivalent-sized model of the Concorde.
Would this reduction scale up very well for a full-size version?
…And if they’re really interested in quick international junkets such as the cited trip between Tokyo and Singapore, wouldn’t it be less challenging in terms of engineering to develop something like Lynx or Skylon, but using a ballistic path?
Point-to-point suborbital (New York-Tokyo) turns out to be a special case of orbital travel. So rather than scaling up a Lynx, you pretty much have to build a fully-orbital system, then land before you complete the first orbit. You get all the rocket equation challenges, and all the em-vee-squared challenges, and all the thermal protection challenges, only to wind up where a 787 could have gotten you with a modicum of patience.
It’s not impossible, but I don’t expect it to happen until human access to orbit is routine and very, VERY cheap.
I think some have the idea that a ballistic intercontinental trajectory would need less delta-v than a fractional orbital one, neglecting to consider that entry deceleration would kill any passengers.
Picky picky. Do the passengers want to live forever?