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Supersonic Flight Without The Sonic Boom
fname writes "Here's a story from Spaceflight Now about a new test aircraft that can travel at supersonic speeds without triggering a sonic boom. The technology works by modifying the shape of the plane. Although it's been believed to be possible for a long time, this is the first actual flight test, barring black box projects I suppose."
What does Guile think about these developments?
It makes it more practical to have supersonic travel in and around cities, which are notoriously noise sensitive. In the past, the routes for such planes were quite limited. Now, if the cost drops, perhaps we'll see them more in the mainstream.
Oh, and there are likely military applications, as well. Anything to reduce chances of someone hearing you coming can help (although, most times, these planes take off far from their mission).
There's supposed to an Earth shattering kaboom?!?!
It seems it merely muffles the sonic boom. The technology doesn't completely silence it.
This is important because the main reason super sonic airplanes are not used more often for civils is because of the sonic boom. The sonic booms can be very loud and disturbs urban areas. The Concord, for example, had to wait to be very far away from populated areas before getting into super sonic speeds. This rwas costly, since the Concord was design to have optimal fuel efficiency at super sonic speeds.
"There is no teacher but the enemy."-Mazer Rackham
It just modifies it so it isn't as annoying. (Spreading the force over a larger area.)
Very useful, yes, but you would still hear it going overhead. (Though I suppose the 'boom' fades as you move away from the plane, and this could speed that up...)
'Sensible' is a curse word.
> Just think. Los Angeles to New York in 3 hours.
What!? I've been getting about 120ms average.
The unofficial
On the contrary, my guess is these low-noise jets will be even bigger gas guzzlers than normal supersonic jets, for three reasons.
1 - Fuel efficiency wasn't mentioned in the article. If it were better, I figure they'd be bragging about it.
2 - Apparantly the main advancement that they did was to have the air heat up near the nose of the aircraft, to make a smooth pressure gradient. Now that heating must come from friction, which takes energy (quite a bit when the air is rushing by at Mach 2).
3 - Current aircraft are designed with loads of computer aerodynamics modelling, with the main design goal being low drag (ie., high fuel efficiency), so if reducing the sonic boom reduced drag, it already would have been discovered and implemented long ago. In subsonic aircraft, design improvements of 0.01% are fairly typical and worth going after, as this is a very mature field of engineering.
I guess we can forget about those 4 hour NYC to Tokyo flights for the time being.
This is simply the most amazing thing I have ever seen. A bunch of civi's were on a naval ship when a hotshot pilot buzzed the ship at supersonic speed. One of them happened to get some amazing video of the pressure wave.
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