DARPA/Boeing X-51A WaveRider

[Ian33]

Here are some drawings of the X-51 internals and 4 development craft in manufacturing - from a DARPA / Boeing Pdf.

 

[airrocket]

WOW X-51 very detailed awesome! And seems the Aussie Queensland just keeps rolling out 3D inward inlet hyper concepts. Those Aussies ever get real hardware funding they will rule the hyper region as they are hyped on hyper. Ever fly subsonic to Australia makes one appreciate a future 2 hour hyper hop. Been following Queensland hyper stuff from way back in the eighties. They just keep at it slow but sure. I wonder if some that hyper enthusiasm is due to the somewhat out-of-the-way worldly location the Aussies inhabit. Anyway we still have leg up on them with the X-51 when comes to hardware. But the X-51 is sporting 80’s X-31 tech 2D inlet technology. From I have been told the 2D inlets are easier to analyses for early on development.

 

[shockonlip]

WOW X-51 very detailed awesome! And seems the Aussie Queensland just keeps rolling out 3D inward inlet hyper concepts. Those Aussies ever get real hardware funding they will rule the hyper region as they are hyped on hyper. Ever fly subsonic to Australia makes one appreciate a future 2 hour hyper hop. Been following Queensland hyper stuff from way back in the eighties. They just keep at it slow but sure. I wonder if some that hyper enthusiasm is due to the somewhat out-of-the-way worldly location the Aussies inhabit. Anyway we still have leg up on them with the X-51 when comes to hardware. But the X-51 is sporting 80’s X-31 tech 2D inlet technology. From I have been told the 2D inlets are easier to analyses for early on development.

I appreciate your cheerleading efforts airrocket !! I will join my voice with yours !!
We are both nypersonic NUT cases, as are many others.

But I just wanted to say that designing a 2D inlets for a waverider, is not the same as designing
a 2D inlet in the past! This is not a critique of the older design process. I'm merely trying to point
out there are similarities between waverider design and inward turning inlet design.

Waverider design is an inverse design process, and so is the 3-D inward turning inlet design process !

Both begin with the designer generating a conical flowfield. There are also waveriders that
begin design with non-conical flowfields, but these are just manifestations of different flowfields
generated by the designer to use to generate the waverider for some useful reason. But let's assume
conical generated waveriders just to see the possible similarities easier.

And then BOTH design processes generate the surfaces of interest (waverider leading edge and underside
surface and upper surface) or (inward turning inlet surfaces) by tracing the streamlines generated by
said flowfields through the flowfield, forward to where they meet the cone shock to match the
desired characteristics of the waverider (surface area/volume) (accelerator/cruiser) or inward turning inlet
(inlet surface requirements), whatever the case.

For the waverider, adding (in this case) a 2-D inlet is another set of streamline traces from
where on the waverider underside the scramjet module is to be, back to the cone shock to
create the cowl and 2-D ramp.

So my point is, that there are interesting similarities between airbreathing waverider design
and inward turning inlet design, and to me, the 2-D inlet on the X-51 is not really the same thing
as a 2-D inlet in the past (again no slam against such things intended).

I don't think we have seen the end of inward turning inlets in the US!

They are taught in hypersonic design classes and there are even neat tools that help these days!

Plus there are algorithms to put inward turning inlets on waveriders as well.

One thing that blows me away about inward turning inlet design, is that there is a 1966 paper
that basically outlines the process. I have seen a modern powerpoint slide graphic on inward
turning inlet design that has EXACTLY (far as I can tell) the same graphic
as in the 1966 paper !! And that 1966 paper referenced Busemann's 1942 paper:
"Die achsensymmetrische kegelige Ueberschallstromung," Luftfahrtforschung 19, 137-144 (1942).

If anyone has a copy, please post if possible.

1942 !!

The modern inward turning inlet design process generalizes it some more by creating something
called the Radial Deviation Parameter (RDP) which generalizes to inward turning (RDP>0), 2-D (non-curved
shock) RDP=0, and outward turning (RDP<0) inlets using the process. Plus the modern process is on cheap
computers.

 

[DSE]

WOW X-51 very detailed awesome! And seems the Aussie Queensland just keeps rolling out 3D inward inlet hyper concepts. Those Aussies ever get real hardware funding they will rule the hyper region as they are hyped on hyper. Ever fly subsonic to Australia makes one appreciate a future 2 hour hyper hop. Been following Queensland hyper stuff from way back in the eighties. They just keep at it slow but sure. I wonder if some that hyper enthusiasm is due to the somewhat out-of-the-way worldly location the Aussies inhabit. Anyway we still have leg up on them with the X-51 when comes to hardware. But the X-51 is sporting 80’s X-31 tech 2D inlet technology. From I have been told the 2D inlets are easier to analyses for early on development.

The UQ hypersonics interest/involvement goes back to Dr. Ray Stalker and his collaboration with the Hypersonic Airbreathing Propulsion Branch at NASA Langley in the 80s/90s, as is mentioned in this UQ new release about the current NASA/UQ MOU, http://www.uq.edu.au/news/index.html?article=14533. The branch funded grants to UQ/Dr. Stalker for fundamental work that could be performed in the then unique T3/T4 expansion tubes. The initial REST inlet work was actually done by Dr. Smart beginning with his postdoc tenure in the branch. The design method went through several iterations/refinements and culminated in a freejet engine test. Some of this is summarized in the HAPB web page at http://hapb-www.larc.nasa.gov/Public/Engines/Rest/Rest.html. Work on the REST type inlet continues to date as part of the Hypersonics Project under the NASA Fundamental Aeronautics Program and is the subject of the aforementioned MOU as well as this UQ release, http://www.uq.edu.au/news/index.html?article=15425. BTW, Dr. Smart abhors the term "inward-turning" as applied to the REST concept, which btw does not utilize a true streamline-traced design technique. Details can be found in the references on the above mentioned web page.

In reality, there is no such thing as real 2-D flow in these "2-D" inlets. That was one of the fallacies of the NASP rogram. This was really proven out during the ground test of the Hyper-X Mach 7 flowpath, where three different width flowpath models were tested, DFX, HXEM and HXFE.

http://hapb-www.larc.nasa.gov/Public/Engines/Dfx/Dfx.html
http://hapb-www.larc.nasa.gov/Public/Engines/Hxem/Hxem.html and
http://hapb-www.larc.nasa.gov/Public/Engines/Hxfe/Hxfe.html

 

[bobbymike]

Some X-51 news from Defense News April 13, 2010:

Boeing Could Expand Hypersonic Follow-on Efforts
By JOHN REED
Published: 13 Apr 2010 18:07
Print Print | Print Email

COLORADO SPRINGS, Colo. - If all goes well with this year's four test flights of the hypersonic Boeing X-51A Waverider, the firm could add a rapid global-strike scramjet to its list of potential follow-up projects, said Steve Johnston, Boeing's director of Advanced Space Exploration.

The list already includes the X-51A+, which would test a scramjet's ability to change direction and splash down onto a targeted area at sea; and Rapid Identification and Prosecution of Targets in Denied Environments (RIPTIDE), which "would be more of an operationally representative configuration" that would include sensors and weapons, Johnston said during an April 13 briefing with reporters here. This, however, is several years away since funding for X-51A+ is not set to begin until fiscal year 2011, according to Johnston. Both RIPTIDE and the X-51A programs are funded by the Air Force Research Laboratory.

The upcoming X-51A tests, set to begin in a matter of weeks, are meant to test the engine, heat-resistant fuselage materials and guidance systems during a five-minute burn while flying faster than Mach 6. This is enough time for the aircraft to reach the hottest, sustained heat levels it is expected to experience as it flies through the upper reaches of the atmosphere at more than six times the speed of sound. Once this is done, the company will begin looking at how to tweak the engine and optimize the X-51A+ to carry precision navigation equipment necessary to fly complex flight patterns, Johnston said.

"The RIPTIDE program will be about further optimizing the airframe; taking weight out of it, making it more of an operationally representative configuration, while also starting to couple some payload style subsystems," Johnston said. "It's still a flight test program ... geared towards a weapons application." He did not elaborate on the specific payloads being carried on the airframe.

Boeing has also begun looking at how to build a hypersonic plane that has deployable wings and landing gear, a serious improvement over today's single-shot scramjets, Johnston said. Johnston could not provide a schedule for RIPTIDE development. He said the X-51A is a high-risk program, and he would be surprised if the company discovered no problems in the upcoming flight tests. The Pentagon is looking at what mix of missiles and aircraft it will use to spy on and strike enemies in heavily defended airspace.

Several areas being studied include a new cruise missile for the U.S. Air Force and Navy, and the Prompt Global Strike effort to allow U.S. commanders to hit a target anywhere on earth with a conventional munition within an hour.

 

[Ian33]

I thought the X-51A was precursor / technology testbed to the X10/100 scale upgrade, which was then to be a precursor to the combined cycle engines being perfected and mated to the scramjet technology - with the final far flung outcome being rapid returnable single stage runway to space access...

 

[CammNut]

From Guy Norris in AvWeek:

"Boeing says the first X-51A test may now take place in May, having twice seen scheduled attempts in March and April scrubbed due to reprioritization of the B-52 to other tests."

 

[flateric]

...

 

[sferrin]

Air & Space Mag put's it more pessimistically as not prior to the end of May. Can't seem to find the post now, but I know it's hanging outside my door at work.

Of course I find it after I posted this. http://blogs.airspacemag.com/daily-planet/2010/04/20/going-hypersonic/

Now reported as a go for the last week of May. Standing army would appear to be a real issue for the program at this point.

What stumps me is they keep putting it off due to "higher priority" tasking for the B-52 apparently. Anybody know what that might be? ???

 

[mkellytx]

What stumps me is they keep putting it off due to "higher priority" tasking for the B-52 apparently. Anybody know what that might be? ???

Scott,

As an alum of the 419th I actually worked on X-51 and some of the higher priority tests. When there's a limited number of jets, limited number of maintainers and a limited number of aircrew; the test that supports the war fighter goes first. That's the kind of decision they're making right now. Hope that gives some SA without telling too much of value .

Cheers

 

[mkellytx]

Well according to Craig Covault http://spaceflightnow.com/news/n1005/16waverider/

"The tests getting underway this month were to have begun in February or March but were delayed when initial B-52 captive carry tests found the coordination of chase aircraft and telemetry acquisition required greater definition, project sources said."

Though given spurious incorrect or non-relevant portions of the article , a grain of salt might be needed.

I spoke to the A/C and co right after the captive carry so I do have some SA as to what's happening. When it comes to a DARPA/AFRL science project or something that will allow the BUFF to support ongoing operations I think you know which they will support. As to confirming or denying any specifics...well I think you know where I'm going.

 

[bobbymike]

From the Air Force Association

Getting Ready to Scram: Air Force officials are preparing to conduct the maiden free flight of the first X-51A hypersonic air vehicle as early as May 25 from Edwards AFB, Calif. A B-52 will release the expendable X-51 over the Pacific Ocean. Spaceflight Now reported Monday that initial captive carry tests on the B-52 showed the need for greater coordination of chase aircraft and telemetry acquisition, thus pushing back the date of the historic first flight. The X-51 features a supersonic combustion ramjet engine designed to propel the vehicle to more than six times the speed of sound. These flights, if successful, would be the first practical demonstration of scramjet technology and could pave the way for new types of ultrafast-striking missiles, reusable aircraft, and even space-access vehicles. The Air Force plans four X-51 flights. (For X-51A background, see Game Changers from the archives of Air Force Magazine.)

 

[mkellytx]

From the Air Force Association

Getting Ready to Scram: Air Force officials are preparing to conduct the maiden free flight of the first X-51A hypersonic air vehicle as early as May 25 from Edwards AFB, Calif. A B-52 will release the expendable X-51 over the Pacific Ocean. Spaceflight Now reported Monday that initial captive carry tests on the B-52 showed the need for greater coordination of chase aircraft and telemetry acquisition, thus pushing back the date of the historic first flight. The X-51 features a supersonic combustion ramjet engine designed to propel the vehicle to more than six times the speed of sound. These flights, if successful, would be the first practical demonstration of scramjet technology and could pave the way for new types of ultrafast-striking missiles, reusable aircraft, and even space-access vehicles. The Air Force plans four X-51 flights. (For X-51A background, see Game Changers from the archives of Air Force Magazine.)

Wouldn't really surprise me, especially after the Falcon thing coming out of Vandy here recently. That chase scheme was pretty Rube-Goldberg. Not that I'd speak to specifics, but you run dress rehearsals (captive carries) to find and fix things before you spend real money. I've gone and made very expensive holes in the desert b/c the money folks didn't agree with the cost benefit stuff...until they became expensive holes.

 

[Steve Pace]

X-51A to fly 25 May according to Air Force Link news.

Steve Pace

 

[shockonlip]

I'm holding my breath !!

Boy, there isn't much left of the waverider surface at the front.
I guess it's enough though to establish the inlet flowfield, and enough
to test the flowfield on the upper surface.

X51 GO GO GO !!

 

[pesholito]

Is this pdf available on the internet or can you post a link to it? Thank you!
Best regards!
Peter

 

[pesholito]

This is perfect! Thank you!
Best regards!
Peter

 

[sferrin]

Any word?

 

[sferrin]

Don't they put out notices of "hey, stay out of this area between X and Y"? ???

 

[Matej]

Probably the violator was on the Z axis

 

[sferrin]

Probably the violator was on the Z axis

And full of Chinese. I wonder why they think a day would make a difference in that case? (If anything it would give more time for everybody to get a front row seat.)

 

[sferrin]

http://www.wired.com/dangerroom/2010/05/air-forces-mach-6-cruise-missile-makes-a-successful-splash/

"The Air Force has successfully launched the X-51 WaveRider hypersonic missile, bringing the military one step closer to a Mach 6 cruise missile that’s 10 times faster than current models.

An observer tells Danger Room the test was “mostly successful,” with over 200 seconds of accelerating powered flight. “Clean separation, perfect engine start, acceleration under power,” our source says. “Some hitches at the end of flight, but overall it’s a magnificent first flight.”

The X-51 is part of an effort to develop a new class of cruise missile that can handle hypersonic flight. The WaveRider — built by Boeing Phantom Works and engine maker Pratt & Whitney Rocketdyne — is built around a scramjet design, which employs a supersonic mix of air and jet fuel to reach extreme speeds.

This test was run from Edwards Air Force Base, Calif. As this embedded video shows, a B-52 had to carry the WaveRider 50,000 feet. After the bomber released the aircraft, an attached solid rocket booster was supposed to accelerate the WaveRider to about Mach 4.5. After the booster fell away, the scramjet was supposed to kick in, taking the aircraft up to Mach 6.

A first flight attempt was scrubbed yesterday, after a tanker ship sailed into the splash zone. We’re waiting for more details, but if all went to plan, this may be the longest-ever hypersonic flight powered by scramjet propulsion."

 

[Trident]

Congrats, must've come as a relief to all involved, after all those last-minute hitches.

 

[sferrin]

Where they were shooting for 300 seconds of powered flight though, getting only 200 seconds sound like more than "Some hitches at the end of flight". I wonder if there was a structural failure of some sort. ??? Hopefully it was something trivial though.


Now they need to get a successful HyFly flight.

 

[bobbymike]

sferrin - I'm guessing combustion problems as in the X-51 lost positive thrust of the SCRAMJET.

 

[sferrin]

sferrin - I'm guessing combustion problems as in the X-51 lost positive thrust of the SCRAMJET.

Where did you hear that?

 

[sferrin]

The next try will be the last shot unless an lot more $$ are ponied up to make some more hardware. The ground test program was cut short as they salvaged some of that HW after some issues fabbing some of the flight bits.

It's just a shame they'd junk the program without ever finding out if the thing worked or not.

 

[flateric]

X-51 Waverider makes historic hypersonic flight

5/26/2010 - EDWARDS AIR FORCE BASE, Calif (AFNS) -- An X-51A Waverider flight-test vehicle successfully made the longest supersonic combustion ramjet-powered hypersonic flight May 26 off the southern California Pacific coast.

The more than 200 second burn by the X-51's Pratt & Whitney Rocketdyne-built air breathing scramjet engine accelerated the vehicle to Mach 6. The previous longest scramjet burn in a flight test was 12 seconds in a NASA X-43.

Air Force officials called the test, the first of four planned, an unqualified success. The flight is considered the first use of a practical hydrocarbon fueled scramjet in flight.

"We are ecstatic to have accomplished most of our test points on the X-51A's very first hypersonic mission," said Charlie Brink, a X-51A program manager with the Air Force Research Laboratory at Wright-Patterson Air Force Base, Ohio. "We equate this leap in engine technology as equivalent to the post-World War II jump from propeller-driven aircraft to jet engines."

The X-51 launched at about 10 a.m. from here, carried under the left wing of an Air Force Flight Test Center B-52 Stratofortress. Then, flying at 50,000 feet over the Point Mugu Naval Air Warfare Center Sea Range, it was released. Four seconds later an Army Tactical Missile solid rocket booster accelerated the X-51 to about Mach 4.8 mach before it and a connecting interstage were jettisoned.
The launch and separation were normal, Mr. Brink said.

Four X-51A cruisers have been built for the Air Force and the (Defense Advanced Research Projects Agency) by industry partners Pratt & Whitney Rocketdyne and Boeing.
Air Force officials intend to fly the three remaining X-51A flight test vehicles this fall, Mr. Brink said.
Air Force officials currently plan to fly each on virtually identical flight profiles, building knowledge from each successive flight.

Hypersonic flight, normally defined as beginning at Mach 5, five times speed of sound, presents unique technical challenges with heat and pressure, which make conventional turbine engines impractical. Program officials said producing thrust with a scramjet has been compared to lighting a match in a hurricane and keeping it burning.

"This first flight was the culmination of a six-year effort by a small, but very talented AFRL, DARPA and industry development team," Mr. Brink said. "Now we will go back and really scrutinize our data. No test is perfect, and I'm sure we will find anomalies that we will need to address before the next flight. But anyone will tell you that we learn just as much, if not more, when we encounter a glitch."

Mr. Brink noted while development of the X-51A's engine and the test program are complex, controlling costs has been a key objective. The team has incorporated or adapted existing proven technologies and elected from the outset not to build recovery systems in the flight test vehicles, in an effort to control costs and focus funding on the vehicle's fuel-cooled scramjet engine.

Mr. Brink said he believes the X-51A program will provide knowledge required to develop the game changing technologies needed for future access to space and hypersonic weapon applications.

 

[sferrin]

Video or it didn't happen.

 

[bobbymike]

sferrin - sorry just guessing as it appears it was not a catastrophic failure it might be something like failure of constant ignition and loss of thrust (again just a guess)

Or it might have just run out of fuel - from the Air Force Association

Hyper Talk: The Air Force's maiden free flight of the X-51A WaveRider hypersonic missile from Edwards AFB, Calif., appears to have gone off well, according to an entry posted late Wednesday at Wired magazine's Danger Room blog. The Air Force had not issued a formal statement on the test by then. But Danger Room contributor, Nathan Hodge, citing one source, said the test was “mostly successful,” with more than 200 seconds of accelerating powered flight by the X-51A vehicle. The X-51 was to be carried aloft by a B-52 bomber out over the southern California coast and then released. Ultimately, its supersonic combustion ramjet engine was meant to ignite and accelerate the vehicle to speeds up to Mach 6 until its fuel expired and it splashed down in the Pacific Ocean. Edwards officials scrubbed Tuesday's flight attempt after a ship sailed into the splash zone.

 

[seruriermarshal]

Cool ! X-51A Range must than 300 km !

 

[sferrin]

Looks like somebody jumped the gun when they said it reached Mach 6. From Boeing's site:

"It was released while flying at approximately 50,000 feet over the Point Mugu Naval Air Warfare Center Sea Range. Four seconds later, a solid rocket booster from a U.S. Army tactical missile accelerated the X-51A to about Mach 4.5 before it and a connecting interstage were jettisoned. The X-51A's engine ignited on a mix of ethylene and JP-7 jet fuel. After a short period, the X-51A ran exclusively on JP-7 jet fuel. The flight reached an altitude of about 70,000 feet and an approximate speed of Mach 5."

http://boeing.mediaroom.com/index.php?s=43&item=1227


I must say, I'm disappointed. An ASALM test vehicle reached a higher speed (Mach 5.4) 30 years ago and it didn't have the massive booster X-51 did. Ah well, better luck next time.

 

[seruriermarshal]

Looks like somebody jumped the gun when they said it reached Mach 6. From Boeing's site:

"It was released while flying at approximately 50,000 feet over the Point Mugu Naval Air Warfare Center Sea Range. Four seconds later, a solid rocket booster from a U.S. Army tactical missile accelerated the X-51A to about Mach 4.5 before it and a connecting interstage were jettisoned. The X-51A's engine ignited on a mix of ethylene and JP-7 jet fuel. After a short period, the X-51A ran exclusively on JP-7 jet fuel. The flight reached an altitude of about 70,000 feet and an approximate speed of Mach 5."

http://boeing.mediaroom.com/index.php?s=43&item=1227


I must say, I'm disappointed. An ASALM test vehicle reached a higher speed (Mach 5.4) 30 years ago and it didn't have the massive booster X-51 did. Ah well, better luck next time.

ASALM

Speed Mach 4.5

http://www.designation-systems.net/dusrm/app4/asalm.html

 

[sferrin]

Yeah, that was the "brochure" speed. One of the PTVs reached Mach 5.4 at 40,000 feet in flight tests. From the link you graciously provided:

" In one of the PTV tests, the missile accidentally accelerated beyond the planned speed, and eventually reached Mach 5.5 at 12200 m (40000 ft)!"

(I posted Mach 5.4 because that's what the article at the Wright Propulsion Labs stated. That was probably ten years ago. If you go there now the link to their "Historical" section is grayed out. Which is too bad because it had some interesting stuff there.)

 

[Trident]

I must say, I'm disappointed. An ASALM test vehicle reached a higher speed (Mach 5.4) 30 years ago and it didn't have the massive booster X-51 did. Ah well, better luck next time.

How long did the ASALM PTV survive that experience though - 10 seconds? 200 seconds? If supersonic combustion and thermal equilibrium were achieved with the X-51 that would still be significant progress.

 

[sferrin]

I must say, I'm disappointed. An ASALM test vehicle reached a higher speed (Mach 5.4) 30 years ago and it didn't have the massive booster X-51 did. Ah well, better luck next time.

How long did the ASALM PTV survive that experience though - 10 seconds? 200 seconds? If supersonic combustion and thermal equilibrium were achieved with the X-51 that would still be significant progress.

Thing is though, the ATACMs booster burned out at Mach 4.5 (some reports say Mach 4.8) and after 200 seconds the missile only reached "approximately Mach 5" which means less-than in the media world (else they'd have said "over Mach 5"). So, in 200 seconds it accelerated between Mach 0.1 and Mach 0.5. Something tells me that even if they'd have gone the full 300 seconds they wouldn't have hit Mach 6. Hopefully I'm proven wrong.

 

[FutureSpaceTourist]

Video or it didn't happen.

Video of the launch and booster ignition, so not sure if this qualifies?

http://www.youtube.com/watch?v=VZUwKX3_uE4

 

[Trident]

Thing is though, the ATACMs booster burned out at Mach 4.5 (some reports say Mach 4.8) and after 200 seconds the missile only reached "approximately Mach 5" which means less-than in the media world (else they'd have said "over Mach 5"). So, in 200 seconds it accelerated between Mach 0.1 and Mach 0.5. Something tells me that even if they'd have gone the full 300 seconds they wouldn't have hit Mach 6. Hopefully I'm proven wrong.

Update, flightglobal reaffirms 200 seconds and Mach 5, indicating the flight performed as expected up to 140 seconds. Reported cause for the premature termination is - wait for it - loss of telemetry... again! Either this is good news because it would qualify as "something trivial" I suppose, or it is bad news because that failure mode is becoming a collective euphemism for more ominous hypersonic test malfunctions

http://www.flightglobal.com/articles/2010/05/27/342468/picture.html

Need to work on getting reliable telemetry sorted out, me thinks

 

[sferrin]

Just do like they did with Sprint and use a mega-jiggawatt transmitter to punch through the ionization layer. ;D Thing is though, telemetry aside, I'd have thought they'd have tracked it on radar so they should still know what the thing did shouldn't they? Or does it automatically self-destruct if telemetry is lost to avoid the possibility of the vehicle going where they don't want it to? (And might this have been the case as well with the HTV flight?) ???

 

[GeorgeA]

Well it might be like the apocryphal story of AJ Foyt (or other bad ass old-time race driver, it doesn't matter):

Reporter: What put you out of the race, AJ?

AJ: Electrical.

Reporter: Electrical?

AJ: Yeah, when the rod came through the block it knocked the alternator off.

Just sayin'.