Posted on 09/28/2007 10:34:42 AM PDT by Freeport
Sustained hypersonic flight above speeds of Mach 5 by vehicles using air-breathing, jet-fuel-powered engines could become achievable within the next dozen years.
Successful recent ground tests of jet-fueled, ramjet/scramjet demonstrator engines by Pratt & Whitney Rocketdyne and Aerojet represent important progress toward flight-testing of three separate hypersonic-vehicle programs.
In September, Pratt & Whitney Rocketdyne (PWR) completed 10 months' testing of a sub-scale combustor for a hydrocarbon-powered, dual-mode ramjet engine designed to operate over a wide range of Mach-number speeds -- that is, multiples of the speed of sound.
Using JP-7 jet fuel, PWR ran the combustor successfully at a variety of Mach numbers from Mach 2.5 to Mach 6.0, demonstrating "desired operability and performance" at each speed, the company said.
Under a DARPA/U.S. Air Force program, Boeing is making the X-51A hypersonic demonstrator aircraft, with the aim of making the first test flight in 2009. Pratt & Whitney Rocketdyne is making the X-1 JP-7 jet-fuel scramjet engine for the X-51A, which is also known as the WaveRider, because effectively it will surf the shock wave of compressed air that the aircraft creates in front of it as it flies at speeds well in excess of Mach 5. Credit: Pratt & Whitney
In April 2007, Pratt & Whitney's X-1 JP-7-fueled demonstrator scramjet engine completed a simulated Mach 5 flight of the X-51A WaveRider -- officially known as the Scramjet Engine Demonstrator - WaveRider, or SED-WR -- at the NASA Langley Research Center in Hampton, Va. The demonstrator engine, which has fitted with full authority digital engine controls and a closed-loop thermal management system that uses the fuel itself as a coolant, was designated the SJX61-1. Credit: Pratt & Whitney Rocketdyne
(Excerpt) Read more at aviation.com ...
Mach 5? What’s the New York to Paris time of that flight?
China Developing Scramjet Propulsion
Sep 2, 2007
By Craig Covault
China is starting to ramp up its scramjet propulsion work—an initiative that will benefit high-speed missile programs while also helping the country to develop advanced aerospace materials, greater computational capabilities and a cadre of young engineers who have matured as a result of cutting-edge engine and aerodynamic challenges.
Slightly longer than the Paris to New York flight time!
When the Auroroa is finally revealed, I'll bet it flies in excess of this speed. And we developed that when, fifteen to twenty years ago?
Yup.........thanks to Al Gore and Clinton.
When was the first flight? couple, three years ago? How is the Australian hypersonic program coming?
Assuming this type of aircraft flies at 50,000 ft., that puts the speed of sound at about 968 ft./sec. and NYC to London is 3460 miles. And assuming it takes about 100 miles to get up to and down from altitude and speed...
That puts the Flight Time around 50 minutes or so. That fast enough for ya?
No one’s flown a hydrocarbon engine yet.
about an hour
WHY 12 years ? The engine works . Build the airframe around it because the designs are already on the board . Should be functional in less than five years if they wanted it to . Seems like we are dealing with the Food and Drug Administration regarding times to use a new medicine .
Tests to date have been logged in seconds, not for hours and multiple cycles. I assume if you show up with a few billion more $ you could get one sooner...
Call Bill Gates & get and see about a loan... ;-)
All of this technology is wonderful....and we’ll never, ever see it in commerical airliners.
One, the economics just aren’t there. We could have had Mach 3 airliners decades ago. It’s cheaper to pack passengers in like sardines into big, fat, slow airplanes.
Two, environmentalists will help kill it. Too fast, too noisy, too poluting, etc.
Airliner performance has been essentially unchanged in 40 years. We’re still stuck in fat, tubular, slow cattle cars. And we’ll live out our lives and die before we see anything different. 787’s are nothing but 707’s with neat computers, plastic parts, and quieter engines.
All of this technology is wonderful....and we’ll never, ever see it in commerical airliners.
One, the economics just aren’t there. We could have had Mach 3 airliners decades ago. It’s cheaper to pack passengers in like sardines into big, fat, slow airplanes.
Two, environmentalists will help kill it. Too fast, too noisy, too poluting, etc.
Airliner performance has been essentially unchanged in 40 years. We’re still stuck in fat, tubular, slow cattle cars. And we’ll live out our lives and die before we see anything different. 787’s are nothing but 707’s with neat computers, plastic parts, and quieter engines.
This was being worked on eons ago (early 90’s) and was probably axed post Gulf War I and Clinton’s Military Cuts. I had a friend on the program in the early 90’s on the Military side of Pratt.
I don't know about Auroroa, but I've seen satellites as bright as the Shuttle that don't show up on any of the tracking programs and they aren't Iridiums. About three weeks ago I saw a pair of them about a degree apart. Quite a sight. They are in an orbital inclination that makes me believe they belong to the USA, not Russia or China.
Constructing an air frame that can withstand that kind of stress is not exactly easy. Ever read up on what happens to the SR-71 during its flights?
Recon aircraft are a little different breed than others. For instance, the SR-71 operating procedure was to let tanks LEAK all over the place on the ground, and when the aircraft got up to its cruising speed, the tanks would seal up due to heat expansion. Well, at least that’s what I’ve heard. So, just because we had the Aurora operational as a recon aircraft (and probably other recon craft that are still black), doesn’t necessarily mean its technology would be able to filter down to the mass market or even regular military market.
Where the heck did they get a mach-6 wind tunnel?
Interesting report. Thanks...
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