Great. Another hypersonic plane that's only 10 years away for the next 40 years.
Quote from: jstrotha0975 on 05/14/2019 12:50 pmGreat. Another hypersonic plane that's only 10 years away for the next 40 years.If you're lucky. No mention of the engine. If SEI is involved we will almost certainly find (surprise surprise) that some kind of SCramjet is essential to make this thing work.
It seems the most insurmountable hurdles back then were (a) the cost of the unobtainium skin required for sustained flight of such a large vehicle much faster than M2 and
(b) the furore over sonic booms - which eventually grounded the Concorde also. AFAIK, both remain hurdles to this day.In comparison to the other show-stoppers on this one, the engines aren't a problem.
I once red that paper about the LAPCAT derived from Skylon. The sonic boom remain such a problem, to go from Europe to australia they had to create a very "imaginative" corridor not to overfly landmasses. This instantly killed the concept, IMHO.
If we ever want ultrafast passenger transportation someday, then it will be through rockets and suborbital, ballistics hops - not through airbreathers and hypersonics. Elon understood this pretty well.
note that a 0.85 propellant mass fraction, kerosene / H2O2 rocketplane, with turbofans, rockets, and nothing else, would have a top speed of 6 km/s, plenty enough to make a 5000 mile ballistic hop with 100 passengers. Fly out of an ordinary airport on the turbofans, quietly, climb to 55000 ft, mach 0.95 and then light the rocket. Boom, suborbital hop, land at another airport on the turbofans.
I checked X-33, shuttle buran orbiters, skylon mass fractions, thanks: all of them 0.80 or more. Your beloved Skylon is above 0.80 too.
Efficient engine or not, NOT overflying landmasses (because no solving the sonic boom) is NOT viable. Way too much constraining. How do you reach Beijing Moscow Frankfurt Berlin without blasting everybody ear drums and windows ?
it is you that is wrong. Long duration hypersonic flight was and still remains a huge tricky thing. Kinetic heating is just horrible. Plus the awful sonic boom even at 80 000 ft or higher.
Boeing perfectly knew about titanium. They actually met Soviet engineers in Paris for further learning ( source Air Force space magazine) Once the L2000 rejected and Tristar underway, Lockheed and NASA ran the YF-12 fleet and some SR-71s right from 1970 to gather data.
Finally, the final 2707-300 design which ditched the VG was far better. Range was near 4000 miles, better than Concorde.
Concorde repeatedly blew tyres that smashed the tanks and intakes the undercarriage being ill placed. Despite Michelin best efforts it remained an unresolved danger (think sts-27 sts-107 foam losses) that finally doomed the aircraft.
Quote from: john smith 19 on 05/15/2019 07:22 amQuote from: jstrotha0975 on 05/14/2019 12:50 pmGreat. Another hypersonic plane that's only 10 years away for the next 40 years.If you're lucky. No mention of the engine. If SEI is involved we will almost certainly find (surprise surprise) that some kind of SCramjet is essential to make this thing work. In some rare spare time yesterday I happened upon a Youtube rendering of a TV programme about the failure of the Boeing SST programme way back when:It seems the most insurmountable hurdles back then were (a) the cost of the unobtainium skin required for sustained flight of such a large vehicle much faster than M2 and (b) the furore over sonic booms - which eventually grounded the Concorde also. AFAIK, both remain hurdles to this day.In comparison to the other show-stoppers on this one, the engines aren't a problem.
Well, Boeing SST - 2707-300 after 1969 - was to be build of titanium. Building Lockheed A-12 family out of that stuff was already extremely difficult. Well in order to pack 250 passengers the 2707-300 was to be extremely long - 300 ft. It would be even heavier than the XB-70 Valkyrie (which was build of stainless steel, incidentally). In the end the expense and flexibility issues just killed the beast. See attached document for more details.
Just a reminder that the heating levels of M5 have been referred to as being like continuous reentry. What can work for a 15 decent is unlikely to prove workable for hours of flight.
Hermeus' range is better than Concorde and that would open up more options. Concorde flew into Atlanta once to show off, but the FAA denied a London to Atlanta route because they were concerned about fuel reserves. Hermeus Corporation is based in Atlanta, so they'll keep additional Atlantic routes in mind.
A valid approach would be to insulate everything and use water to keep everything cool.
Good Luck Branson, you need it !This will be fun to see how this project will struggle with various problemfirst design, construction, if R&R is able to build the needed enginesnext to that finance issue and high operation costVirgin Galactic will have hell of with Fuselage to endure the heat during flight.For ComparisonSR-71 skin temperature during Mach 3 +316°C or 600 F° airframe active cooledConcorde skin temperature during Mach 2 +127°C or 261 °FConcorde fuselage expand 300mm during flightSR-71 Titanium fuselage expand 1016mm during flight
BTW a quick look at biz jets shows only the Embraer Lineage and Boeing and Airbus models have room for more than 10 passengers. Everything else is 10 or less. So in addition to being a FOAK passenger carrying M5 aircraft it is also a large FOAK aircraft in its class.
Umm, no. There are plenty of business jets that can accommodate more than that. The thing with business jets, particularly the larger ones, is that what they can accommodate, and what they are actually equipped for, are often pretty different, especially as you get into the larger sizes. If you come across a bizliner (one of those Boeing/Airbus ones, or the E-170/E-190 derivative Embraers) that's truly only equipped for 19 passengers, you're looking at separate full-size bedrooms, showers, and a lot of open floor space.
Someone mentioned 19 is the magic number so TSA doesn't require fancy inspections?
Hermeus got some kind of SBIR grant for some of their earlier work. Some time in the last 1-2 years I think. I wonder what the best way to look for what their submission would be? Company name? Principle investigators? [EDITHad a bit of a nose around the SBIR database and found this and thisIn contrast the Hermeus founders only show up on some awards for general hypersonic design study work. It looks like the key stuff is (or was) being done by "Advanced Cooling Technologies" PA for precooler design, who were going to license the tech to GoHYpersonic. May have done so. I'm not sure if there's a delay on releasing current year SBIR reports but I don't think so. I think REL might have a case for patent infringement based on the description of the precooler work as well. ]
Most of patents REL had were around frost control on designs which they aren't actually using anymore as they aren't liquifying the air anymore.
Came across an interesting interview with Gene Holloway of Aerion talking about biz jets, their supersonic plane, sonic booms over land and how they plan to deal with it. Dynamically modelling the atmosphere in front and using inversion layers to reflect the boom is something I've not heard of before..https://newatlas.com/aircraft/aerion-interview-as2-supersonic-business-jet/
The tail number N60304 is not assigned. A test vehicle would need a tail number registered with the FAA. Must be a mockup or something put together to impress the investors.
Quote from: RonM on 11/10/2021 02:05 amThe tail number N60304 is not assigned. A test vehicle would need a tail number registered with the FAA. Must be a mockup or something put together to impress the investors.Not assigned to an aircraft, but is currently reserved and assigned to Hermues' founder. Could simply be pending a database update.
Quote from: edzieba on 11/10/2021 10:43 amQuote from: RonM on 11/10/2021 02:05 amThe tail number N60304 is not assigned. A test vehicle would need a tail number registered with the FAA. Must be a mockup or something put together to impress the investors.Not assigned to an aircraft, but is currently reserved and assigned to Hermues' founder. Could simply be pending a database update.You can reserve an N number without assigning it to a specific airframe. I have a tail number reserved for my airplane but haven't yet registered it as I'm not done building it yet.
While this Quarterhorse prototype was not designed to fly, it is much more than just a showpiece. Building this vehicle was an exercise in multidisciplinary design, manufacturing, and the integration of complete systems.
"Hermeus Goes Full Throttle At Unveil Of Quarterhorse Prototype"https://www.hermeus.com/blog-quarterhorse-unveilQuoteWhile this Quarterhorse prototype was not designed to fly, it is much more than just a showpiece. Building this vehicle was an exercise in multidisciplinary design, manufacturing, and the integration of complete systems.
No shock diamonds? Didn't look too tied down either.
Quote from: webdan on 11/11/2021 09:18 pmNo shock diamonds? Didn't look too tied down either.I'm skeptical about the "prototype" claim as well, but to be honest, there are two heavy chains running to large concrete blocks behind the item.
Money...
I noticed a lot of Brass watching that unveiling.Clearly a major source of future funding and/or customers are the military.
You'd be surprised how many tubes we have to bend. Like, so many tubes. Luckily, our new tube bending machine is up and running, and the team is pretty stoked.
https://twitter.com/hermeuscorp/status/1576989113084960768QuoteYou'd be surprised how many tubes we have to bend. Like, so many tubes. Luckily, our new tube bending machine is up and running, and the team is pretty stoked.
“The Notre Dame facility allowed us to create conditions similar to what we’ll see in flight,” said CTO Glenn Case. “Completing this testing on the ground significantly de-risks our Quarterhorse flight test campaign which will begin late next year.”
Quote from: su27k on 11/21/2022 02:37 am“The Notre Dame facility allowed us to create conditions similar to what we’ll see in flight,” said CTO Glenn Case. “Completing this testing on the ground significantly de-risks our Quarterhorse flight test campaign which will begin late next year.”Well if they've actually got their engines sorted like they say, perhaps they'd be better off ditching Quarterhorse (what a stupid name for a fast aircraft) entirely and asking Lockheed-Martin if they can borrow one particular prototype they recently showcased?Seeing Darkstar actually fly would be very, very, cool indeed!!!
A movie prop is not going to be of much utility.
Quote from: edzieba on 11/21/2022 08:26 amA movie prop is not going to be of much utility.As a validated design concept / showpiece made by people who know what is required for hypersonic flight?? That movie prop is far more likely to fly than the mess that they trundled out at their big reveal.
Atlanta-based hypersonics firm, Hermeus, has just taken delivery of an F100-229 engine from Pratt & Whitney. Best known for powering USAF F-15 Eagles and F-16s, the F100 will propel Heremeus’ hypersonic Darkhorse aircraft to Mach 2.8 on the way to Mach 5.Hermeus announced receipt of its first Pratt & Whitney engine early this month. “We always knew that we were going to larger and more modern gas turbine engines with better thrust than the J85,” company CEO, AJ Piplica, told me.The need for a more powerful conventional powerplant for Hermeus’ turbine-based combined cycle engine (TBCC) falls into line with the company’s march from a small, remotely-piloted Quarterhorse test aircraft to a larger reusable hypersonic UAS called Darkhorse and, at some point in the future, to a 20 passenger hypersonic aircraft called Halcyon.
Got to witness a test of a turbo ram jet engine yesterday with @hermeuscorp. Absolutely wild experience. My favourite doc shoot so far. My dream company to work for.
Considering that the Chimera turbine-based combined cycle engine of the Hermeus Quarterhorse includes a vintage General Electric J85 turbojet, the decision by Hermeus to select the Pratt & Whitney F100 turbofan as the turbine portion of the Chimera II powerplant for the forthcoming Hermeus Darkhorse demonstrates the flexibility exhibited by Hermeus Aerospace with respect to using existing supersonic turbofan engines for the gas turbine component of its TBCC engines being developed for hypersonic aircraft designs.
Quote from: Vahe231991 on 07/14/2023 01:27 amblah blah blah....Someone please stop this AI crap
blah blah blah....
Quote from: 12345 on 08/10/2023 09:21 amQuote from: Vahe231991 on 07/14/2023 01:27 amblah blah blah....Someone please stop this AI crapAgreed. There have been numerous comments like yours about this poster. I go back and forth if it's AI, a non-English speaker with a bad translator Bablesfish, a young person trying to sound intelligent and/or important and getting their rocks off seeing their posts here and interactions with others, or an elder with time on their hands scouring NSF for old threads to revive as a hobby (and to annoy Jim). I've got them on IGNORE, but will look at their posts once in a while just to see what kind of drivel they posted that day. Once in a while they randomly make a decent post, but otherwise they're just an annoying mosquito. I've seen worse, but NSF could lose them without pain.
The post written by me in question isn't a product of artificial intelligence. I never wrote "blah blah blah" because I am both an English speaker and multilingual speaker. I was just commenting on the latest news on development of the Darkhorse because Hermeus Aerospace had to make a decision on what turbofan should be used for the gas turbine part of the Chimera II TBCC engine for the Darkhorse engine because it knows that the J85 turbojet that is part of the Quaterhorse's powerplant is technologically obsolete compared to the F100.
Quote from: Vahe231991 on 08/11/2023 03:25 pmThe post written by me in question isn't a product of artificial intelligence. I never wrote "blah blah blah" because I am both an English speaker and multilingual speaker. I was just commenting on the latest news on development of the Darkhorse because Hermeus Aerospace had to make a decision on what turbofan should be used for the gas turbine part of the Chimera II TBCC engine for the Darkhorse engine because it knows that the J85 turbojet that is part of the Quaterhorse's powerplant is technologically obsolete compared to the F100.What you wrote here and other places is equivalent to "blah blah blah" because it doesn't add anything of substance to the discussion. It is just filler.I mean did the "decision really demonstrate flexibility"? And if so, why is it necessary to point out here?
Quote from: Jim on 08/11/2023 05:54 pmQuote from: Vahe231991 on 08/11/2023 03:25 pmThe post written by me in question isn't a product of artificial intelligence. I never wrote "blah blah blah" because I am both an English speaker and multilingual speaker. I was just commenting on the latest news on development of the Darkhorse because Hermeus Aerospace had to make a decision on what turbofan should be used for the gas turbine part of the Chimera II TBCC engine for the Darkhorse engine because it knows that the J85 turbojet that is part of the Quaterhorse's powerplant is technologically obsolete compared to the F100.What you wrote here and other places is equivalent to "blah blah blah" because it doesn't add anything of substance to the discussion. It is just filler.I mean did the "decision really demonstrate flexibility"? And if so, why is it necessary to point out here?I'm emphasizing that Hermeus Aerospace had to make a decision of which jet engine should be used as the gas turbine portion of the Chimera engine, and that because the Chimera II is a bigger engine, it required a larger engine for its gas turbine component. Hermeus Aerospace opted for existing jet engines to serve as the gas turbine components for the Chimera and Chimera II TBCC engines in order to save billions of dollars in research and development costs and years of schedule, and since the Darkhorse design is slightly bigger and faster than the Quarterhorse, I'd imagine that Hermeus Aerospace was looking for an existing jet engine to act as the gas turbine component of the Chimera II that would have a powerful-enough thrust-to-weight ratio to propel the Darkhorse to its planned Mach 5 speed. If the Halcyon is ever built following flight testing of the Darkhorse, Hermeus Aerospace could optimize the Halcyon's TBCC engine to use as the gas turbine component either the F100 or F110.
Quote from: JAFO on 08/10/2023 06:17 pmQuote from: 12345 on 08/10/2023 09:21 amQuote from: Vahe231991 on 07/14/2023 01:27 amblah blah blah....Someone please stop this AI crapAgreed. There have been numerous comments like yours about this poster. I go back and forth if it's AI, a non-English speaker with a bad translator Bablesfish, a young person trying to sound intelligent and/or important and getting their rocks off seeing their posts here and interactions with others, or an elder with time on their hands scouring NSF for old threads to revive as a hobby (and to annoy Jim). I've got them on IGNORE, but will look at their posts once in a while just to see what kind of drivel they posted that day. Once in a while they randomly make a decent post, but otherwise they're just an annoying mosquito. I've seen worse, but NSF could lose them without pain.The post written by me in question isn't a product of artificial intelligence. I never wrote "blah blah blah" because I am both an English speaker and multilingual speaker. I was just commenting on the latest news on development of the Darkhorse because Hermeus Aerospace had to make a decision on what turbofan should be used for the gas turbine part of the Chimera II TBCC engine for the Darkhorse engine because it knows that the J85 turbojet that is part of the Quaterhorse's powerplant is technologically obsolete compared to the F100.
Quote from: Vahe231991 on 08/11/2023 07:50 pmQuote from: Jim on 08/11/2023 05:54 pmQuote from: Vahe231991 on 08/11/2023 03:25 pmThe post written by me in question isn't a product of artificial intelligence. I never wrote "blah blah blah" because I am both an English speaker and multilingual speaker. I was just commenting on the latest news on development of the Darkhorse because Hermeus Aerospace had to make a decision on what turbofan should be used for the gas turbine part of the Chimera II TBCC engine for the Darkhorse engine because it knows that the J85 turbojet that is part of the Quaterhorse's powerplant is technologically obsolete compared to the F100.What you wrote here and other places is equivalent to "blah blah blah" because it doesn't add anything of substance to the discussion. It is just filler.I mean did the "decision really demonstrate flexibility"? And if so, why is it necessary to point out here?I'm emphasizing that Hermeus Aerospace had to make a decision of which jet engine should be used as the gas turbine portion of the Chimera engine, and that because the Chimera II is a bigger engine, it required a larger engine for its gas turbine component. Hermeus Aerospace opted for existing jet engines to serve as the gas turbine components for the Chimera and Chimera II TBCC engines in order to save billions of dollars in research and development costs and years of schedule, and since the Darkhorse design is slightly bigger and faster than the Quarterhorse, I'd imagine that Hermeus Aerospace was looking for an existing jet engine to act as the gas turbine component of the Chimera II that would have a powerful-enough thrust-to-weight ratio to propel the Darkhorse to its planned Mach 5 speed. If the Halcyon is ever built following flight testing of the Darkhorse, Hermeus Aerospace could optimize the Halcyon's TBCC engine to use as the gas turbine component either the F100 or F110.Again, so what? Did the decision really demonstrate flexibility? Both the F-100 and F-110 are multiple decades old engines. The F-100 was contracted for USN and USAF usage in the F-14/15, both of which entered service in the 1970's.
Quote from: Hog on 08/16/2023 02:24 pmQuote from: Vahe231991 on 08/11/2023 07:50 pmQuote from: Jim on 08/11/2023 05:54 pmQuote from: Vahe231991 on 08/11/2023 03:25 pmThe post written by me in question isn't a product of artificial intelligence. I never wrote "blah blah blah" because I am both an English speaker and multilingual speaker. I was just commenting on the latest news on development of the Darkhorse because Hermeus Aerospace had to make a decision on what turbofan should be used for the gas turbine part of the Chimera II TBCC engine for the Darkhorse engine because it knows that the J85 turbojet that is part of the Quaterhorse's powerplant is technologically obsolete compared to the F100.What you wrote here and other places is equivalent to "blah blah blah" because it doesn't add anything of substance to the discussion. It is just filler.I mean did the "decision really demonstrate flexibility"? And if so, why is it necessary to point out here?I'm emphasizing that Hermeus Aerospace had to make a decision of which jet engine should be used as the gas turbine portion of the Chimera engine, and that because the Chimera II is a bigger engine, it required a larger engine for its gas turbine component. Hermeus Aerospace opted for existing jet engines to serve as the gas turbine components for the Chimera and Chimera II TBCC engines in order to save billions of dollars in research and development costs and years of schedule, and since the Darkhorse design is slightly bigger and faster than the Quarterhorse, I'd imagine that Hermeus Aerospace was looking for an existing jet engine to act as the gas turbine component of the Chimera II that would have a powerful-enough thrust-to-weight ratio to propel the Darkhorse to its planned Mach 5 speed. If the Halcyon is ever built following flight testing of the Darkhorse, Hermeus Aerospace could optimize the Halcyon's TBCC engine to use as the gas turbine component either the F100 or F110.Again, so what? Did the decision really demonstrate flexibility? Both the F-100 and F-110 are multiple decades old engines. The F-100 was contracted for USN and USAF usage in the F-14/15, both of which entered service in the 1970's.This decision in some ways demonstrated flexibility because Hermeus Aerospace had to decide whether to use the F100, F110, F119, or a brand new turbofan for the gas turbine portion of the Chimera II TBCC powerplant to be used for the Darkhorse and Halcyon, even though the F100, F110, and F119 have greater power-to-weight ratios that the J85 that is part of the Quarterhorse's Chimera engine. What was the rationale by Hermeus Aerospace for picking the F100 rather than the F110 as the gas turbine component of the Chimera II engine?
If Hermeus use MIPCC, then they throw oxidizer in front of the turbofan compressors to keep them cool and boost performance. Turbofan thinks it flies at Mach 2 when real velocity is Mach 4+ REL precooler use a helium loop, cooled by LH2.
Given that REL determined near-liquid air was good enough for their purposes, I wonder if that opens the opportunity for using a different cryogen for the heat exchanger, assuming Hermeus is not dumping either water or LOx directly into the stream...
Hermeus has selected Cecil Airport in Jacksonville, Florida for its hypersonic engine test facility. Named HEAT (High Enthalpy Air-Breathing Test Facility), this facility will be Hermeus’ largest and most technologically advanced test site to date and become a national asset for hypersonic testing. The site will also be the initial base for Hermeus’ high-Mach flight test capabilities starting in 2026, expanding cadence and affordability of the nation’s flight test infrastructure.We announced our plans for the new facility at a groundbreaking ceremony at Cecil Airport in Jacksonville. Hermeus executives and employees were joined by U.S. Congressman Aaron Bean (FL- 04), U.S. Congressman John Rutherford (FL-05), State Sen. Clay Yarborough (R-Jacksonville), Mayor Donna Deegan, Florida Department of Commerce officials, JAXUSA officials, and other community leaders. The HEAT facility will provide continuous high flow rate, high enthalpy and low-pressure conditions required for high-supersonic and low-hypersonic flight modeling. This capability will make the facility an important asset to more effectively test and field various hypersonic technologies – not only for Hermeus but also for the Department of Defense and its commercial partners. Hermeus will test a variety of engines and propulsion subsystems at HEAT – from the Pratt & Whitney F100 engine to Hermeus’ proprietary hypersonic Chimera engine. The facility will be built in phases with initial sea-level static engine tests starting before the end of 2024. Future phases of the facility will introduce continuous high-Mach vitiated air flow to simulate more flight-like high-Mach testing conditions on the ground.