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Shockwave Images Help NASA In Development of 'Quiet' Supersonic Jet (go.com)
An anonymous reader writes: NASA is working on developing a next-generation supersonic jet that can break the sound barrier with a soft "thump" instead of a sonic boom. They are using a technique called schlieren imagery to "visualize supersonic flow phenomena with full-scale aircraft in flight" with the sun as the backdrop for the photos. According to a NASA blog post, viewing shock waves and their density is crucial to the project so engineers can work on a design to minimize those reverberations. While the Quiet Supersonic Technology (QueSST) research aircraft is being developed, stunning images were captured of a supersonic jet flying at Mach 1.05 with the sun in the background. NASA says when QueSST is operational, it could "unlock the future to commercial supersonic flight over land," essentially ushering in a new era of aviation that could allow us to get from point A to point B faster and without the loud roar of the Concorde as it breaks the sound barrier.
No, which is what doomed the Boeing Sonic Cruiser. Airlines prefer cheap operating costs over aircraft speed. In fact, they typically run their current fleet slower than the aircraft are able to cruise, for fuel economy reasons.
Are modern engines as efficient at Mach 1.5 as they are at Mach 0.9?
No. The engine doesn't notice the speed, the intake takes care of that. But to create thrust, the exhaust flow must be faster than the intake flow, and making the exhaust flow faster lowers the overall efficiency of the engine. This is why subsonic engines have a high bypass ratio while for supersonic engines bypass ratio must be kept low.
You know it's time for the next revolution when your rulers' names end with roman numerals.
> Supersonic flight adds a new source of drag, called wave drag [wikipedia.org],
As the author of the article you are linking to (if you don't believe me, click History and look) I find it somewhat odd that you apparently didn't *actually read it*.
Wave drag is primarily and effect in the *transonic* from about M0.8 to 1.1 or 1.2, and then basically disappears at speeds above that. Jet airliners spend a significant portion of their flight time dealing with it, which is why it is important for modern air travel.
Supersonic aircraft do indeed use much more fuel than subsonic, but it's not due (primarily) to wave drag, and designing to lower boom does not necessarily upset it for the worse.
Actually, being able to get from point A to point B faster than a day's worth of travel will probably save countless billions in time and money for everyone from executives to a family going to Disney World, or Europe.
Bah humbug! YMMV, but for me, most of my travels are within 400-1000 miles or so (or 1 - 3 hours in the air). For those on the shorter end of that, it often takes less time to just drive it once you take into account time to get to/from the airports, screening, baggage claim, etc. While supersonic may provide a noticeable difference in some cases, they really need to reduce the end point issues if they want it to seem significantly faster.