General Hypersonic Flight Related Topics

[Star One]

I did have a thread on here that was about using a hypersonic launcher but that was too specific & as there seems to be quite a fair bit of development going on in this area I thought it might be an idea to start a more general thread about it. This thread is for developments that are not related to Skylon. As a general point in relation to this forum I've added the thread as hypersonic research can include straddling the line between general aviation & space flight the hypersonic vehicles for example are often launched in the same way.

Anyway I start the thread with this article.

Waltham missile maker Raytheon Co. has just taken on a tall order from the Department of Defense: Create a cruise missile that could travel more than five times the speed of sound.

Raytheon is getting $20 million from the Defense Advanced Research Projects Agency, or DARPA, the Pentagon branch best known for having sponsored the invention of the Internet. This time, the agency wants a technology that weapons designers have dreamed of since the 1930s — a hypersonic missile that travels so fast there’s virtually no defense against it.

http://www.bostonglobe.com/business/2015/05/26/going-hypersonic-raytheon/Qnrg2YJUdMo2SXiVphoBaO/story.html#

[Star One]

AF Chief Scientist: Air Force Working on New Hypersonic Air Vehicle.

Presuming they are meaning a drone or aircraft here, not a missile.


Read more: http://defensetech.org/2015/06/01/af-chief-scientist-air-force-working-on-new-hypersonic-air-vehicle/#ixzz3bvjakFd4
Defense.org

[vulture4]

the cruise missile application continues to look like the most obvious to me:

"The new air vehicle effort will progress alongside an Air Force hypersonic weapons program. While today’s cruise missiles travel at speeds up to 600 miles per hour, hypersonic weapons will be able to reach speeds of Mach 5 to Mach 10, Air Force officials said. The new air vehicle could be used to transport sensors, equipment or weaponry in the future, depending upon how the technology develops"

[Star One]

What they could be talking about here is the HSSW.

http://www.lockheedmartin.com/us/products/high-speed-strike-weapon-hssw.html

I still wonder if REL's technology could play a part in something even more ambitious than the HSSW.

[docmordrid]

What they could be talking about here is the HSSW.

http://www.lockheedmartin.com/us/products/high-speed-strike-weapon-hssw.html

I still wonder if REL's technology could play a part in something even more ambitious than the HSSW.

With the former chief engineer of Rolls Royce taking the Managing Directors job at REL ISTM something's afoot. A sideways move before an acquisition? Or someone western govts can be assured can mature a possible defense windfall?

[TrevorMonty]

Unfortunately wars and weapons seem to drive technology development. The plus side is technology from a hyper sonic cruise missile should enable development of civil hyper sonic aircraft.

[Star One]

New article on the SR-72 with a very little more detail on its design in the text. Got a feeling the related magazine article might be more extensive.

http://www.popsci.com/inside-americas-next-spyplane

[jee_c2]

Here is an article about communicating with hypersonic vehicles in flight:
http://www.spacedaily.com/reports/Communicating_with_hypersonic_vehicles_in_flight_999.html

(about a method: how to overcome the craft surrounding, EM waves reflecting plasma layer)

[Star One]

Pulse detonation engine and continuous detonation wave engines.

Various bits & pieces of info.

http://nextbigfuture.com/2015/06/pulse-detonation-engine-and-continuous.html

Notice the PDE space plane.

[Star One]

German space researchers reboot effort to launch hypersonic space plane

The Deutsches Zentrum für Luft- und Raumfahrt (DLR), Germany's aerospace research center, has renewed decade-old plans for a suborbital passenger space plane that could fly from Europe to Australia in under 90 minutes. The rocket-powered SpaceLiner, originally conceptualized as a 50-passenger hypersonic airliner, has now been given new urgency and direction with a roadmap for flights within the next 20 years, SpaceLiner project lead Martin Sippel told Aviation Week at last month's American Institute of Aerodynamics and Astronautics' Space Planes and Hypersonics Conference in Glasgow. Sippel spoke at the conference, presenting on SpaceLiner's technical progress and the program's mission definition—which now includes potentially delivering satellites and other payloads to space.

http://arstechnica.com/science/2015/08/german-space-researchers-reboot-effort-to-launch-hypersonic-space-plane/

[john smith 19]

Unfortunately wars and weapons seem to drive technology development. The plus side is technology from a hyper sonic cruise missile should enable development of civil hyper sonic aircraft.

True.

Unlikely to be much use in building LVs.

Pulse detonation engine and continuous detonation wave engines.

Various bits & pieces of info.

http://nextbigfuture.com/2015/06/pulse-detonation-engine-and-continuous.html

Notice the PDE space plane.

The plane is interesting.

Especially considering how far a SCRamjet crew carrying vehicle remains

German space researchers reboot effort to launch hypersonic space plane

http://arstechnica.com/science/2015/08/german-space-researchers-reboot-effort-to-launch-hypersonic-space-plane/

And for only $33Bn.

IIRC that's just over 1/2 cost of the Shuttle programme in 2010+ dollars (the figure I saw was $60Bn).

Here is an article about communicating with hypersonic vehicles in flight:
http://www.spacedaily.com/reports/Communicating_with_hypersonic_vehicles_in_flight_999.html

(about a method: how to overcome the craft surrounding, EM waves reflecting plasma layer)

Neat idea. It's one of those "Why didn't anyone think of it before" notions.   

Reduce losses by impedance matching the plasma.

IIRC the Spring ABM did this to control the missile in flight but needed radar signals in the MW range to punch through the sheath.

The joker in this pack is of course how the plasma sheath thickness compares to the usual range of radio frequencies people use for comms.

It would be quite ironic if needed HF (relying in ionospheric reflection from the plasma there) to get through the plasma sheath around your M5 vehicle.

It would also mean all those GHz satcomms systems would be useless as well.

[clongton]

A hypersonic flight from New York to Los Angeles would take about 30 minutes but if that includes high acceleration at NY and high deceleration at LA then what kind of g's are we talking about? Could civilian passengers withstand that? And what would be the actual cruise time at altitude?

[A_M_Swallow]

A hypersonic flight from New York to Los Angeles would take about 30 minutes but if that includes high acceleration at NY and high deceleration at LA then what kind of g's are we talking about? Could civilian passengers withstand that? And what would be the actual cruise time at altitude?

Limit acceleration to 0.5 g, hypersonic is Mach 5+ so round off to 2000 m/s then it will take about 6.8 minutes to reach that speed. Total journey will be less than 3/4 hour. Unless the aircraft has to fly subsonic until it reaches the countryside.

[Rocket Surgeon]

In the eternal words of one of my uni mates at UQ: "Scramjets Suck"

In all seriousness, Scramjets are an incredibly difficult technology to make work across varying speeds as the entire engine needs to be designed around the bow shockwaves created by any leading edges. The problem is, these shockwaves change angle as you speed up and you lose efficiency and/or risk destroying your vehicle if the shocks don't contact the right points. Hence, you're entire vehicle (or at least the engines) need to morph as they speed up, and at hypersonic speeds, that's a tall order. At the University of Queensland, they were at one point investigating vehicles that would sweat COPPER in order to protect themselves form the hyper sonic heat. But, at a constant hypersonic speed for a short time, they are great (espeacially if they are...'disposable').

This has one very unfortunate implication for anyone working on scramjet research. It will really only have military applications, either as hyper sonic cruise missiles or hypersonic spy planes. As a space launch system where you have to constantly speed up and get out of the atmosphere ASAP, well as I said above, "Scramjets suck". 

[Star One]

Breakneck Speed: New Russian Jet Engine to Propel Aircraft to 9,000 Kmh

Read more: http://sputniknews.com/military/20150823/1026084410/russia-creates-breakthrough-jet-engine.html#ixzz3kCCLCbSi

[Star One]

China may have conducted test flight of world's fastest aircraft

China may have recently conducted a successful test of the fastest hypersonic aircraft in the world, reports Hong Kong newspaper Ta Kung Pao.

According to a report released Friday on the official website of state-owned aerospace and defense giant Aviation Industry Corporation of China (AVIC), one of its test flight centers has completed an initial test flight on an unspecified high-altitude, super-fast aircraft with a "unique flying style."

http://www.wantchinatimes.com/news-subclass-cnt.aspx?id=20150921000033&cid=1101

[Eric Hedman]

New article on Lockheed Hypersonic jet research:

http://www.ft.com/intl/cms/s/0/781f6c08-ead6-11e5-bb79-2303682345c8.html#axzz435BPHDRS

[Star One]

For a non-paywall version. Space flight actually gets a specific mention in this.

https://www.flightglobal.com/news/articles/lockheed-pushing-1-billion-mach-6-airbreather-423198/

[Star One]

DARPA revives turbine-ramjet concept for hypersonics

A turbine-based combined cycle (TBCC) propulsion system to enable routine hypersonic flight by a vehicle that can take-off and land from a runway is back on the agenda at the Defense Advanced Research Projects Agency (DARPA) after a five-year hiatus.

https://www.flightglobal.com/news/articles/darpa-revives-turbine-ramjet-concept-for-hypersonics-426735/

[john smith 19]

DARPA revives turbine-ramjet concept for hypersonics

A turbine-based combined cycle (TBCC) propulsion system to enable routine hypersonic flight by a vehicle that can take-off and land from a runway is back on the agenda at the Defense Advanced Research Projects Agency (DARPA) after a five-year hiatus.

https://www.flightglobal.com/news/articles/darpa-revives-turbine-ramjet-concept-for-hypersonics-426735/

It always amuses me when I see the term "integrated" in one of these announcements.

The most "integrated" way to do this is of course to ditch the ramjet part entirely, which is basically what SABRE does.

The problem then becomes how to keep the airframe from melting. An interesting  idea in this regard would be make it out of RCC with a refractory oxidation resistant metal. Atomic Layer Deposition produces multiple thin, highly conformant layers which could be very well matched to the underlying RCC, substantially reducing cracking and raising use temperature over current silica glass coatings.