I’m perusing a story on CNN about a vehicle that can fly at Mach 6, or more than 4,500 miles/hr. While that seems like a crazy speed, my response is, what took so long?
I think about that almost every time I board a plane these days. It took the same six or so hours to fly across the US 20 years ago that it does now. I know that the cockpits have changed significantly, and other improvements have been made, but flight times haven’t budged. And yes, I’m aware of the whole Concorde thing, and it’s really a shame that the program had to be cancelled.
Back to the story on CNN. Does it mean that we’re actually going to see faster commercial airplanes? Not likely, or at least not anytime soon. The Pentagon’s X-51A Waverider hypersonic flight test vehicle is just that -- a test vehicle.
Later today, the 25-foot-long vehicle will be dropped off of the wing of a converted B-52 bomber off the California coast. It will attempt to fly for five minutes at Mach 6. Remember, Orville and Wilbur’s first flight only last a few seconds. According to the story, “The technology could eventually bring missiles or airplanes to the other side of the planet in minutes instead of hours.”
If successful, the test plane will simply fade into the Pacific Ocean and not be recovered. The Air Force claims that it’s prohibitively expensive to try to recover the planes. The cost of the program was not disclosed.
From my understanding, faster speed = high fuel consumption. During the days of the Concorde, high fuel consumption wasn't seen as a problem. Today, consumers and the market are more focused on things that, at least, appear to be good for the environment.
Exceeding 660 miles per hour above sea level creates the boom. Once an aircraft breaks the sound barrier, it creats an extended boom that is heard by anyone who is near the supersonic craft. So it isn't just one single boom -- it's continuous as long as the craft is exceeding the the sound barrier, even if those on the ground experience it as a single boom. So, on a flight from L.A. to N.Y that exceeds the sound barrier, everyone on the ground between the two cities would experience the window-shaking (and sometimes window-breaking) boom.
NASA, however, is looking at strategies for taking the boom out of high speed aircraft:
OK, that explains a lot. When I read the article -- which didn't address sonic booms -- I wondered whether the small size of the craft negated the sonic booms. Maybe they just take the boom over the ocean and move on.
Yes, Rich, I also saw that CNN article, andI too was surprised. I was under the (perhaps mistaken) impression that speeds exceeding 600 mph would cause sonic booms that would be unacceptable to residents. And thus, there was a wall against faster speeds. Yet at 4,500 mph, why no sonic booms?
What's getting in the way of speed? Is it just cost or is it, like usual, government regulation? Even in its heyday, the Concorde was only allowed to fly at its advertised speed over open ocean. I think it was "illegal" for them to fly a New York to LA route at those speeds.
At the Design News webinar on June 27, learn all about aluminum extrusion: designing the right shape so it costs the least, is simplest to manufacture, and best fits the application's structural requirements.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This radio show will show what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.