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.

Comments

More important than the sonic boom

[Nutria]

Are modern engines as efficient at Mach 1.5 as they are at Mach 0.9?

NASA or NACA?

[fsagx]

This headline could have been from the 40's or 50's. This is the way supersonic flow has been visualized as long as it has been studied. The supersonic wind tunnel and the Schlieren setup at the university I attended appeared pretty ancient to me in the 1980s.

This will only be used on business jets, if at all

[Aviation Pete]

Supersonic flight adds a new source of drag, called wave drag, which comes on top of all other drag. It depends on the slenderness of the plane, but can easily double the total amount of drag. Optimizing the design for less pronounced shock waves will increase drag yet again, so fuel consumption per mile flown will make the cost of supersonic travel prohibitive. After all, the travel speeds of modern airliners (Mach 0.78 to 0.855) is typically a bit lower than the design speed of early jet airliners like the Convair 990 (Mach 0.87) or the Vickers VC-10 (Mach 0.89). That was half a century ago!

But there is a pocket of aviation where progress has been made in flight speed: Business jets! While the first generation flew more slowly than airliners (Lockheed JetStar, Lear Jet 25), the latest designs are quite a bit faster (Cessna Citation X, Gulfstream V) at up to Mach 0.935. Why? There is a peeing contest going on among their owners who is the fastest. A very small segment of mankind is licking their fingers at a new chance for showing off. A supersonic business jet would be a sure sell to this crowd, even if the operating cost per mile doubles.

Well, see it this way: This is a chance for the other 99.9% of mankind to lower the Gini coefficient a bit.

Re:This will only be used on business jets, if at

[Aviation Pete]

Where does the article even hint at wave drag disappearing at higher supersonic speed?

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.

Wrong. Why don't you do some basic fact-checking yourself before wrongly accusing others?