Author Topic: Hermeus hypersonic plane  (Read 34484 times)

Offline Asteroza

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Hermeus hypersonic plane
« on: 05/14/2019 02:45 am »
So yet another supersonic startup decloaked. Apparently aiming for a hypersonic aircraft. Apparently got VC funding based on the strength of their hypersonic propulsion concept, which is unfortunately not disclosed.

https://www.hermeus.com/

Notable that the founders are ex-Generation GO members, which is part of the stable of SEI startups, and it seems like they bailed out after the X-60A announcement. Ordinarily with the hypersonic talk, I would have expected Dr. Olds of SEI to be an advisor, but he's notably absent...

Offline jstrotha0975

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Re: Hermeus hypersonic plane
« Reply #1 on: 05/14/2019 12:50 pm »
Great. Another hypersonic plane that's only 10 years away for the next 40 years.

Offline john smith 19

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Re: Hermeus hypersonic plane
« Reply #2 on: 05/15/2019 07:22 am »
Great. 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.  :(
MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 2027?. T&C apply. Trust nothing. Run your own #s "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Offline CameronD

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Re: Hermeus hypersonic plane
« Reply #3 on: 05/16/2019 03:59 am »
Great. 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.
With sufficient thrust, pigs fly just fine - however, this is not necessarily a good idea. It is hard to be sure where they are
going to land, and it could be dangerous sitting under them as they fly overhead.

Offline Archibald

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Re: Hermeus hypersonic plane
« Reply #4 on: 05/16/2019 04:17 am »
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.

https://en.wikipedia.org/wiki/LAPCAT

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.

It is also possible to "cheat" ballistics to get a longer range through ricochet trajectories - see the works of Preston H. Carter, the father of Hypersoar. He reworked Sanger skip-glide concept with modern tools and found it could work, although at a smaller scale.
Also this https://isulibrary.isunet.edu/doc_num.php?explnum_id=95
« Last Edit: 05/16/2019 04:24 am by Archibald »
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Offline john smith 19

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Re: Hermeus hypersonic plane
« Reply #5 on: 05/16/2019 06:44 am »
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
And you'd be wrong. Watch the programme. What killed the Boeing design was it's weight kept going up, partly due to the very complex (and heavy, and probably unreliable) all moving swing wing. Looked very cool on the presentations, actually a massive PITA to design and mfg.

Titanium was available but only Lockheed had the skills (inside the APD who built the SR71. And that's where they stayed, along with the understanding of how to build a M3 aircraft that didn't need variable geometry). OTOH North American had built a M3 aircraft 10x bigger than the SR71 (the XB70) out of stainless steel, because it was expected you'd need to build them by the 100, not the 10. While the XB70 was a bad idea as a bomber as a basis design for an SST it would have been quite reasonable.
Quote from: CameronD
(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.
What grounded the Concorde was the Air France crash that killed everyone on board.  :( Prior to that the design had flown for 30 years with a perfect safety record.

The problem with takeoff noise was the generation of aircraft Concorde was designed to compete with were turbojets. This was around the time of the shift to turbofans. It was expected that the engine and fuselage  improvements the makers wanted to introduce for the 17th copy (they'd worked out how to eliminate needing the afterburners. Concorde was a "supercruise" aircraft for 30 years without anyone thinking how astonishing that was) would have substantially reduced all noise.

At M5+ both the engines and the skin are problems. Modern M2+ aircraft (even the old F111) are actually low bypass ratio turbofans, not pure turbojets (like those of Concorde and the XB70). The fan blades at the front of the engine can handle around M2.2 airflow but not much above. Since it's likely to be a small production run you can't justify a custom engine just for this application. So at M5+ engines are a problem. AFAIK the lightest SCramjet had a T/W ratio of 2:1. The J58's on the SR71 (mid 50's jet engine tech) were about 5.5 with the nacelle doubling the weight (but absolutely crucial for M3.3 cruise). BTW keep in mind the SR71 SOP was to take off with just enough fuel to get to the tanker and on-load most  of it's fuel.  IOW it's actually a 2 plane system. Acceptable in a military context but no airline will put up with such a system.

So yes, at M5+ cruise the engines are going to be a problem.

M5+ is described as "continuous re-entry." So for hypersonic cruise it's very tough.

Sonic boom control might be the easy part of the problem to solve.

The American SST programme is something of a model of how not to innovate. The lesson was repeated (with the same results) for the X-33 programme. Different players, same failure.  :(
« Last Edit: 05/16/2019 07:06 am by john smith 19 »
MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 2027?. T&C apply. Trust nothing. Run your own #s "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Offline john smith 19

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Re: Hermeus hypersonic plane
« Reply #6 on: 05/16/2019 06:56 am »
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.
Unless you have a very efficient engine design. If you have the range you can still do the trip in a reasonable time.

BTW REL's design was the slow vehicle. The DLR proposed a Kerosene SCramjet that couldn't make the range target.

Quote from: Archibald
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.
That also needs an "IMHO".
Quote from: Archibald
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.
You might like to look up the mass fractions of actual aircraft to find out how tough that is, starting with Concorde and the SR71
« Last Edit: 05/16/2019 07:12 am by john smith 19 »
MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 2027?. T&C apply. Trust nothing. Run your own #s "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Offline Archibald

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Re: Hermeus hypersonic plane
« Reply #7 on: 05/16/2019 11:44 am »
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.
« Last Edit: 05/16/2019 11:55 am by Archibald »
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Offline Star One

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Hermeus hypersonic plane
« Reply #8 on: 05/16/2019 12:53 pm »
Thread link cross-posted into the existing hypersonic and flight thread.

https://forum.nasaspaceflight.com/index.php?topic=37698.msg1381522#msg1381522
« Last Edit: 05/16/2019 12:56 pm by Star One »

Offline john smith 19

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Re: Hermeus hypersonic plane
« Reply #9 on: 05/18/2019 01:34 pm »
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.
Perhaps you should read what I wrote again. Slowly.
The mass fraction is always going to be tough. SABRE is what makes it possible.

Quote from: Archibald
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 ?
The EU accepted REL's strategy so they thought it viable enough to fund REL for the LAPCAT II programme.
This is the relevant design as it's a M5 plane we're talking about. Still no word of how Hermeus plans to solve this problem. 
Quote from: Archibald
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.
As I've noted before "continuous reentry" How these guys propose to solve the problem other than "We'll build a really cool aircraft" still remains a blank sheet of paper.  :(
Quote from: Archibald
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.
Knowing about what you can do with a few sq ft of alloy is rather different to building nearly a whole aircraft out of it. The classic stories are that marking the alloy with a felt tip pen ate through the alloy, while Chrome Vanadium tools had to be pickled to remove one of the elements that also lead to Titanium failure. These are the lessons you learn when you work alloys for  the first time on a large scale. 

Quote from: Archibald
Finally, the final 2707-300 design which ditched the VG was far better. Range was near 4000 miles, better than Concorde.
And had it been the design they started with it might have gotten built.  :(

One of the key elements that made Concorde possible was the (very) subtle shape of its wings. The chines on the SR71 did something similar (and APD certainly understood how important they were). It allowed a fixed wing with adequate performance across the whole operating speed range. Even the Soviets, when they stole the design, did not realize this. It was only when they tried to build the design they realized they didn't know enough and had to resort to canards.
Quote from: Archibald
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.
Until Air France took off with a massive overload of both fuel and passengers and managed to kill them all.  :(

Those facts turned an unfortunate situation into a catastrophe.  :(

However none of this adds to my knowledge of how Hermeus plans to solve the design problem, either in materials or engine tech.

Other than demonstrating that M5 flight is harder than M2+ is there anything you know about their design?
« Last Edit: 05/18/2019 01:37 pm by john smith 19 »
MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 2027?. T&C apply. Trust nothing. Run your own #s "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Offline john smith 19

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Re: Hermeus hypersonic plane
« Reply #10 on: 08/08/2020 01:53 pm »
Yes it's necro but they have caught the eye of USAF section that operates the presidents flight.
MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 2027?. T&C apply. Trust nothing. Run your own #s "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Offline libra

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Re: Hermeus hypersonic plane
« Reply #11 on: 08/08/2020 03:51 pm »
Great. 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.

Offline john smith 19

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Re: Hermeus hypersonic plane
« Reply #12 on: 08/08/2020 06:33 pm »
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.
A bunch of things killed it. Staring with Congress deciding to cut funding.  Boeing scrapping their swing wing design (very cool and very complex and heavy) and basically replacing it with the Lockheed approach (more conservative and frankly more doable) cost a lot of money.

Personally reading that attachment suggests they didn't really have a deep grasp of just how much heat they were going to deal with.

However this is OT for the thread title.

Hermeus benefits from knowing all this already, and the 5 decades improvement in modelling.

Just a reminder that the heating levels of M5 have been referred to as being like continuous  reentry. What can work for a 15 min decent is unlikely to prove workable for hours of flight.
« Last Edit: 08/09/2020 08:05 am by john smith 19 »
MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 2027?. T&C apply. Trust nothing. Run your own #s "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Offline ncb1397

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Re: Hermeus hypersonic plane
« Reply #13 on: 08/08/2020 06:36 pm »

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.

You think this is going to run for hours? At Mach 5, New York to London is like 1 hour. What do you think the range is going to be? The example they give on their website is new york to paris, so I guess that is a bit longer. But I think they would be going slower over land.

edit: The website says 4600 miles at 3300 mph. That is 1.39 hours.
« Last Edit: 08/08/2020 07:13 pm by ncb1397 »

Offline RonM

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Re: Hermeus hypersonic plane
« Reply #14 on: 08/08/2020 09:08 pm »
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.

Offline john smith 19

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Re: Hermeus hypersonic plane
« Reply #15 on: 08/08/2020 10:53 pm »
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.
Wrong tense.

Hermeus has a planned range of 4000nm, which is better than Concorde

What it ends up being, if it gets built, is anyone's guess.  :(
« Last Edit: 08/08/2020 11:06 pm by john smith 19 »
MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 2027?. T&C apply. Trust nothing. Run your own #s "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Offline Robotbeat

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Re: Hermeus hypersonic plane
« Reply #16 on: 08/09/2020 01:36 am »
A valid approach would be to insulate everything and use water to keep everything cool.
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Offline john smith 19

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Re: Hermeus hypersonic plane
« Reply #17 on: 08/09/2020 07:48 am »
A valid approach would be to insulate everything and use water to keep everything cool.
The "Wet wall" was proposed for the X20 but only for the pilot compartment. "Sweat" cooling systems are fixed duration designs. BTW at the stated range of 4000nm (1nm being 1852m and M1 being 340ms) that's 2 hrs 1 min and 2 secs of flight.

Given the considerable scepticism when Virgin Galactic announced they are building an M3 aircraft of this size I'll just cross post some comments on what M3 designs face.

Quote from: Michel Van
Good Luck Branson, you need it !

This will be fun to see how this project will struggle with various problem
first design, construction, if R&R is able to build the needed engines
next to that finance issue and high operation cost

Virgin Galactic will have hell of with Fuselage to endure the heat during flight.
For Comparison

SR-71 skin temperature during Mach 3 +316°C or 600 F° airframe active cooled
Concorde skin temperature during Mach 2 +127°C or 261 °F

Concorde fuselage expand 300mm during flight
SR-71 Titanium fuselage expand 1016mm during flight
And this is for a company that has actually built vehicles of the kind of size and designed to carry passengers, with an engine partner (Rolls Royce) who knows quite a lot about engines for M2+ aircraft.

At M5 I think we can comfortably multiply those issues.

At M3 you have 2 known models of crewed aircraft design and construction (the XB70 in SS honeycomb being the other) you could "borrow" if you didn't want do come up with your own approach.

At M5 that narrows to just the X15. It would be interesting to see how much the X15 would have had to have growth to do a runway takeoff (or conversely how much it's 1500lb of test equipment and pilot would have had to have shrunk).

I'll also note that at Generation Orbit they spent 9 years building a Kerolox sub orbital rocket with a bought in engine and failed to launch anything.  :(

Now it's possible that that delay was due to complex internal management and funding issues that were nothing to do with their technical abilities and, unencumbered by such politics and better funding, their rate of progress will vastly outstrip their rate at GO.

I will wish them well and look forward to seeing what progress they make in what is a very bold goal.

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.
« Last Edit: 08/09/2020 08:21 am by john smith 19 »
MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 2027?. T&C apply. Trust nothing. Run your own #s "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Offline john smith 19

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Re: Hermeus hypersonic plane
« Reply #18 on: 08/09/2020 09:07 am »
In case anyone is wondering what a 19 passenger biz jet looks like. It looks like one of these
GTOW 54.5 tonnes.
« Last Edit: 08/09/2020 09:08 am by john smith 19 »
MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 2027?. T&C apply. Trust nothing. Run your own #s "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Offline libra

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Re: Hermeus hypersonic plane
« Reply #19 on: 08/09/2020 04:18 pm »
Before Flight International took their archive away, I downloaded all the stuff about Dassault own SSBJ. project (1998).

Offline gtae07

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Re: Hermeus hypersonic plane
« Reply #20 on: 08/11/2020 11:30 am »
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.

Something in the Global series or a large-cabin Gulfstream, for example, has plenty of room to fit 19 seats, and there are some equipped up to that level.  But you won't typically find them actually equipped for that; the largest models tend to fit other amenities like divans (basically a couch), extra-wide seats, credenzas with pop-up entertainment systems, separate pilot rest quarters, even bedrooms or showers.  More common is in the 12-16 passenger range, for aircraft in this size class.  You can see images of typical seating arrangements just searching by something like "(model) seating"; manufacturers will show examples and charter operators will often post their cabin configurations so their potential customers can see what the options are.

19 passengers is also one of those regulatory "magic numbers".   If you can carry more than 19 passengers, you're required to have a flight attendant.  That's why so many business aircraft are limited to that number, and it's why small commuters like the Beech 1900 have that limit as well.

Offline john smith 19

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Re: Hermeus hypersonic plane
« Reply #21 on: 08/11/2020 01:32 pm »

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.
Yes those are the 3 I saw that were up front about being able to do 19 passengers.

Otherwise that leaves the POTUS sleeping in his seat. Not really the image you want to project when people hear the phrase "Air Force One," is it?

It's a sub regional airliner but that's still huge for a FOAK M5 aircraft, given the next one down is the X15.

MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 2027?. T&C apply. Trust nothing. Run your own #s "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Offline Robotbeat

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Re: Hermeus hypersonic plane
« Reply #22 on: 08/11/2020 01:47 pm »
The Marine Force One (depending on model) helicopter only has like 12-20 seats. So being smaller isn’t a showstopper for Presidential use.
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Offline Asteroza

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Re: Hermeus hypersonic plane
« Reply #23 on: 08/12/2020 04:03 am »
Someone mentioned 19 is the magic number so TSA doesn't require fancy inspections?

Offline john smith 19

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Re: Hermeus hypersonic plane
« Reply #24 on: 08/12/2020 07:10 am »
Someone mentioned 19 is the magic number so TSA doesn't require fancy inspections?
Surely baggage inspection is for little people?

Although keeping nice things out of the hands of the Thieves Support Association is probably a good idea in general.

Still wondering how they will solve the cooling issues.

TA Hempellheimers book on hypersonics wasn't called "Surviving the Heat Barrier" for nothing.  :(
« Last Edit: 08/12/2020 07:12 am by john smith 19 »
MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 2027?. T&C apply. Trust nothing. Run your own #s "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Offline john smith 19

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Re: Hermeus hypersonic plane
« Reply #25 on: 08/14/2020 06:16 am »
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?
[EDIT
Had a bit of a nose around the SBIR database and found this  and this

In 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.  ]
« Last Edit: 08/14/2020 07:07 am by john smith 19 »
MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 2027?. T&C apply. Trust nothing. Run your own #s "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Offline Seamurda

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Re: Hermeus hypersonic plane
« Reply #26 on: 08/16/2020 01:02 am »
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?
[EDIT
Had a bit of a nose around the SBIR database and found this  and this

In 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.  ]

I don't think that the general concept of precooling will be protected and if it ever was those patents would have expired.

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.

Offline john smith 19

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Re: Hermeus hypersonic plane
« Reply #27 on: 08/16/2020 07:02 am »
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.
They never were.  Not liquifying the air was one of the major REL innovations about SABRE.

I'm actually thinking about the shape of the HX and the airflow through it.

MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 2027?. T&C apply. Trust nothing. Run your own #s "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Offline CameronD

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Re: Hermeus hypersonic plane
« Reply #28 on: 08/18/2020 07:31 am »
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/
With sufficient thrust, pigs fly just fine - however, this is not necessarily a good idea. It is hard to be sure where they are
going to land, and it could be dangerous sitting under them as they fly overhead.

Offline john smith 19

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Re: Hermeus hypersonic plane
« Reply #29 on: 09/21/2020 08:12 pm »
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/
To put this in perspective. M5 (with M1 at 340 m//s) is about 588 micro seconds/metre.
Now that's plenty of time for modern processors to calculate what changes would need to be made but then you have the mechanical time constants of how long any sort of throttle or flight control needs to react to make an observable change.

Obviously if you're looking at an air layer 100m in front of the nose, rather than 1m you have a great deal more time to do whatever it is they are planning to do.

Might work, might not. Time will tell.
MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 2027?. T&C apply. Trust nothing. Run your own #s "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Offline Asteroza

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Re: Hermeus hypersonic plane
« Reply #30 on: 11/09/2021 11:57 pm »
https://twitter.com/hermeuscorp/status/1458118805482266630

https://twitter.com/thesheetztweetz/status/1458119784185348103

Looks like Hermeus did a dog and pony show of their Quarterhorse vehicle. The showed what appears to be a dev engine running with a pretty afterburner shot, but the overall vehicle seems to be lacking certain parts like flight controls, so a partial mockup perhaps?

Offline RonM

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Re: Hermeus hypersonic plane
« Reply #31 on: 11/10/2021 02:05 am »
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.

Offline edzieba

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Re: Hermeus hypersonic plane
« Reply #32 on: 11/10/2021 10:43 am »
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.
Not assigned to an aircraft, but is currently reserved and assigned to Hermues' founder. Could simply be pending a database update.

Offline gtae07

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Re: Hermeus hypersonic plane
« Reply #33 on: 11/10/2021 07:07 pm »
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.
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.

Offline RonM

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Re: Hermeus hypersonic plane
« Reply #34 on: 11/10/2021 07:32 pm »
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.
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.

It's already past the renewal date (09/23/2020) and purge date (10/30/2021).

Offline SciNews

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Re: Hermeus hypersonic plane
« Reply #35 on: 11/11/2021 07:49 am »
"Hermeus Goes Full Throttle At Unveil Of Quarterhorse Prototype"
https://www.hermeus.com/blog-quarterhorse-unveil
Quote
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.

Offline Robotbeat

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Re: Hermeus hypersonic plane
« Reply #36 on: 11/11/2021 01:36 pm »
I noticed a lot of Brass watching that unveiling.

Clearly a major source of future funding and/or customers are the military.
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Offline CameronD

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Re: Hermeus hypersonic plane
« Reply #37 on: 11/11/2021 09:11 pm »
"Hermeus Goes Full Throttle At Unveil Of Quarterhorse Prototype"
https://www.hermeus.com/blog-quarterhorse-unveil
Quote
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.

{emphasis mine} They're also calling it a "full-scale prototype".  Even if they did only have "4 months" to build it, the build quality of that (better they call it a "mock-up" than a full scale prototype)..object is so stunningly poor I'm amazed they're not embarrassed to show it in public and especially to the military!   What did they make it out of?? Cardboard and tacks?!??  That thing must be an insult to aerospace engineers everywhere.  :o

Although I must admit it's the prettiest jet engine test stand I've seen in a while.
« Last Edit: 11/11/2021 09:28 pm by CameronD »
With sufficient thrust, pigs fly just fine - however, this is not necessarily a good idea. It is hard to be sure where they are
going to land, and it could be dangerous sitting under them as they fly overhead.

Offline webdan

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Re: Hermeus hypersonic plane
« Reply #38 on: 11/11/2021 09:18 pm »
No shock diamonds? Didn't look too tied down either.

Offline CameronD

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Re: Hermeus hypersonic plane
« Reply #39 on: 11/11/2021 09:22 pm »
No shock diamonds? Didn't look too tied down either.

Don't worry, if they bolted those hefty foot-pads to the concrete, that thing ain't going anywhere  ;D
 
With sufficient thrust, pigs fly just fine - however, this is not necessarily a good idea. It is hard to be sure where they are
going to land, and it could be dangerous sitting under them as they fly overhead.

Offline Rocket Science

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Re: Hermeus hypersonic plane
« Reply #40 on: 11/11/2021 11:36 pm »
They handed out hearing protection to the attendees but should have added "eye protection" due to the host's "loud" jacket... ;D
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Offline darkenfast

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Re: Hermeus hypersonic plane
« Reply #41 on: 11/12/2021 01:33 am »
No 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.
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Offline Asteroza

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Re: Hermeus hypersonic plane
« Reply #42 on: 05/19/2022 10:27 am »
Some retro-future pseudo vintage marketing art...

https://twitter.com/hermeuscorp/status/1526938601870831621

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Offline CameronD

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Re: Hermeus hypersonic plane
« Reply #44 on: 05/31/2022 12:45 am »
No 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.

Of course they have to put some kind of hold-back in place...  Folks really aren't that gullible.

Money...

Well.. maybe they are.  Well done, Hermeus! :o
With sufficient thrust, pigs fly just fine - however, this is not necessarily a good idea. It is hard to be sure where they are
going to land, and it could be dangerous sitting under them as they fly overhead.

Offline john smith 19

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Re: Hermeus hypersonic plane
« Reply #45 on: 09/24/2022 01:16 pm »
I noticed a lot of Brass watching that unveiling.

Clearly a major source of future funding and/or customers are the military.
Well yes, the USAF part that's putting up some of the funding for this is the part that runs Air Force One.

You could be looking at the new ride for POTUS in the future.  :)
MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 2027?. T&C apply. Trust nothing. Run your own #s "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Offline john smith 19

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Re: Hermeus hypersonic plane
« Reply #46 on: 09/24/2022 01:52 pm »
I'd been offliine so thought I'd just revisit this one. Taking a look around their website they like to say it's built on legacy tech. The J85-21 has indeed been around for a long time and it's civilian variant had powered quite a few lear jets.

I saw this page. It suggests they have tested the engine package (or someone has tested an engine package) of pre-cooler turbojet and ram burner to SR-71 speed, but only the ramburner above that.

Since it's been known that ramjets can fly to at least M5 since the 60's (if not the 50's) this is not exactly pushing the known (and known for a very long time) SoA.

I've also added Kelly Johnsons memoir of the SR-71 development process, along with similar one for the J58 at the end.

[EDIT. One thing Lockheed didn't seem to have was diffusion bonding of Titanium. That was being worked out by North American Aviation's LA site. That included the break-even point between hogging out and assembly in computer costing programs  and ways to reuse metal support bars between different evacuated tool assemblies. One obvious question was why didn't they use thinner metal to make the tooling packs out of. The didn't need to be very thick at all. This could significantly increase flexiiblity and speed of mfg since Hermeus say they are planning to make the full size one of Ti alloy. ]

The last attachment is a longer history and break down of some of the issues of SR71 design and build.

Remember Boom cut top speed to M1.7 to make the job easier, but Hermeus pushes it about 1.5x higher than the Blackbird.

One side point that Concorde engineers noted. Using tin/lead solder melted at 188c, meaning anything hotter than this would start to fall apart unless cooled. Yet another practical reason to keep the speed down.  Historically NASA have been weary of solder and use crimping and actual welding for wiring.  Modern lead-free solders melt at 217°C/422°F. Don't know if that's good enough for M5.

Hermeus are claiming their Quarterhorse test drone will do flight tests from 2023, but I don't think they've mentioned what speed it can reach.

« Last Edit: 09/29/2022 08:59 am by john smith 19 »
MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 2027?. T&C apply. Trust nothing. Run your own #s "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Offline FutureSpaceTourist

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Re: Hermeus hypersonic plane
« Reply #47 on: 10/03/2022 05:39 pm »
https://twitter.com/hermeuscorp/status/1576989113084960768

Quote
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.

Offline john smith 19

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Re: Hermeus hypersonic plane
« Reply #48 on: 10/03/2022 08:37 pm »
https://twitter.com/hermeuscorp/status/1576989113084960768

Quote
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.
I really wouldn't.  IIRC a CNC pipe bender was one of SX's first big purchases. It's a very sensible idea if you want to make repeatable complex 3d shapes reliably.

But if they are still going with a pre-cooler those pipes will have have to be a lot smaller than the stuff in the clip. The stuff in the Reaction pre-cooler has a wall thickness of about 0.001".

OTOH if they can make a pre-cooler work (which they seem to have de-emphasised on their website) then there is less of a need to use legacy, non air-cooled turbojets. The pre-cooler in front means (in principle) you could use any modern engine as the air at the compressor front face would be at standard conditions. On take off you would probably bypass the pre-cooler as the air is not especially hot, progressively routing more and more of the fuel flow through it before it got to the engine.
[EDIT. BTW that think they showed on the video is a non-flying version of Quarterhorse. Flight capable versions are supposedly coming in 2023. Not exactly sure what it's purpose is, or why it needs to be anchored by concrete blocks if it's non-flying.  :(  ]

I'll look forward to their first test flight.
« Last Edit: 10/08/2022 08:32 pm by john smith 19 »
MCT ITS BFR SS. The worlds first Methane fueled FFSC engined CFRP SS structure A380 sized aerospaceplane tail sitter capable of Earth & Mars atmospheric flight.First flight to Mars by end of 2022 2027?. T&C apply. Trust nothing. Run your own #s "Extraordinary claims require extraordinary proof" R. Simberg."Competitve" means cheaper ¬cheap SCramjet proposed 1956. First +ve thrust 2004. US R&D spend to date > $10Bn. #deployed designs. Zero.

Offline su27k

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Re: Hermeus hypersonic plane
« Reply #49 on: 11/21/2022 02:37 am »
https://www.hermeus.com/press-release-tbcc-milestone

HERMEUS COMPLETES HYPERSONIC MILESTONE WITH ENGINE TESTS

Hermeus has demonstrated turbojet to ramjet transition within its engine, Chimera. This is one of the most important technological feats to making operational hypersonic flight a reality.

Chimera is a turbine-based combined cycle engine (TBCC) – which basically means it’s a hybrid between a turbojet and a ramjet. The ability to switch between these two modes allows Hermeus’ first aircraft, Quarterhorse, to take off from a regular runway and then accelerate up to high-Mach speeds.

The cost and speed at which the Hermeus team achieved this milestone is notable. Hermeus designed, built, and tested Chimera in 21 months for $18 million.

“This achievement is a major technical milestone for Hermeus,” said CEO AJ Piplica. “But more than that, it’s a proof point that demonstrates how our small team can rapidly design, build, and test hardware with budgets significantly smaller than industry peers.”

The testing took place at the Notre Dame Turbomachinery Laboratory which provides heated air to simulate high-Mach temperatures and pressures.

“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.”


WHAT HAPPENS WHEN THE ENGINE “TRANSITIONS”?

At low speeds Chimera is in turbojet mode – just like any jet aircraft. But as the temperature and the speed of the incoming air increase, turbojets hit their performance limit. This happens at around Mach 2.

Chimera has a pre-cooler that reduces the temperature of the air coming into the turbojet. This allows Hermeus to squeeze out a bit more performance from the turbojet before transitioning to ramjet.

At around Mach 3, Chimera begins to bypass the incoming air around the turbojet and the ramjet takes over completely.

A ramjet is a simple propulsion system which “rams” the incoming high-pressure air to create compression. Fuel is mixed with this compressed air and ignited for thrust. Ramjets are optimal between Mach 3 and Mach 5.


“AIR-BREATHING” ENGINES VS ROCKET ENGINES

Hermeus’ TBCC engine is unique in the field of hypersonics. Most hypersonic platforms are powered by a rocket engine. But this approach makes reusability much harder and inherently more dangerous for passenger flight.

By making a full-range air-breathing hypersonic engine that does not require a rocket to accelerate, Hermeus is setting the stage for operational hypersonic flight – meaning aircraft that can be rapidly re-used.

An additional benefit of this engine design is that it accommodates existing transportation infrastructure. Hermeus aircraft are designed to be operational at traditional airports.

This is important not just for hypersonic testing, but critical given Hermeus’ goal of radically accelerating passenger travel through hypersonic flight.


BUILDING CHIMERA

An essential manufacturing principle at Hermeus is vertical integration.

Manufacturing in-house allows for a tight feedback loop between engineers and technicians which is key to the company’s ability to iterate quickly. Additionally, vertical integration eases reliance on outside vendors and allows for better control of the supply chain.

Another important factor in building Chimera is additive manufacturing. About 15% of the engine is 3D printed which enabled rapid development.


WHAT’S NEXT?

With mode transition successfully demonstrated, the Hermeus team is now racing to manufacture the first Quarterhorse aircraft that will begin flight testing in late 2023.

Offline CameronD

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Re: Hermeus hypersonic plane
« Reply #50 on: 11/21/2022 03:21 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!!!  :)
« Last Edit: 11/21/2022 03:26 am by CameronD »
With sufficient thrust, pigs fly just fine - however, this is not necessarily a good idea. It is hard to be sure where they are
going to land, and it could be dangerous sitting under them as they fly overhead.

Offline edzieba

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Re: Hermeus hypersonic plane
« Reply #51 on: 11/21/2022 08:26 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.

Offline CameronD

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Re: Hermeus hypersonic plane
« Reply #52 on: 11/21/2022 11:37 pm »
A 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.
With sufficient thrust, pigs fly just fine - however, this is not necessarily a good idea. It is hard to be sure where they are
going to land, and it could be dangerous sitting under them as they fly overhead.

Offline edzieba

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Re: Hermeus hypersonic plane
« Reply #53 on: 11/21/2022 11:45 pm »
A 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.
It was designed to look good on film, and be vaguely plausible. It is of no value as a scale demonstrator for an unrelated vehicle.

Offline Vahe231991

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Re: Hermeus hypersonic plane
« Reply #54 on: 07/14/2023 01:27 am »
Quote
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.

https://www.forbes.com/sites/erictegler/2023/06/08/hermeus-is-plugging-an-f-15-engine-into-its-hypersonic-test-aircraft/ [from June 8, 2023]

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.

Offline FutureSpaceTourist

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Re: Hermeus hypersonic plane
« Reply #55 on: 08/10/2023 07:03 am »
https://twitter.com/thebrianmcmanus/status/1689417362292793345

Quote
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.

Offline 12345

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Re: Hermeus hypersonic plane
« Reply #56 on: 08/10/2023 09:21 am »

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.

Someone please stop this AI crap

Offline JAFO

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Re: Hermeus hypersonic plane
« Reply #57 on: 08/10/2023 06:17 pm »

blah blah blah....

Someone please stop this AI crap

Agreed. 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.
« Last Edit: 08/10/2023 07:25 pm by JAFO »
Anyone can do the job when things are going right. In this business we play for keeps.
— Ernest K. Gann

Offline Vahe231991

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Re: Hermeus hypersonic plane
« Reply #58 on: 08/11/2023 03:25 pm »

blah blah blah....

Someone please stop this AI crap

Agreed. 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.

Offline Jim

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Re: Hermeus hypersonic plane
« Reply #59 on: 08/11/2023 05:54 pm »
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.

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?
« Last Edit: 08/11/2023 05:57 pm by Jim »

Offline Vahe231991

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Re: Hermeus hypersonic plane
« Reply #60 on: 08/11/2023 07:50 pm »
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.

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.

Offline Hog

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Re: Hermeus hypersonic plane
« Reply #61 on: 08/16/2023 02:24 pm »
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.

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.

Paul

Offline Hog

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Re: Hermeus hypersonic plane
« Reply #62 on: 08/16/2023 02:48 pm »

blah blah blah....

Someone please stop this AI crap

Agreed. 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.
emphasis mine
You state that you are an English and multilingual speaker, but is English your native language?  Your posts read like they are AI created.  Seriously, go back and try to read some of your posts out loud.  I bet you are left gasping for air due to the run on sentence structure so prevalent in your posts. 
If you have to go searching for info on a topic, perhaps you shouldn't be posting about that topic.  All us space "outsiders" have the same access to the web that you do.  There's a LOT of trash on the web, don't make NSF.com,
 your dumping ground, please.  If you honestly want to learn, ask questions, there's still quite a few people around who would help you.
Paul

Offline Vahe231991

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Re: Hermeus hypersonic plane
« Reply #63 on: 08/16/2023 03:24 pm »
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.

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?

Offline Jim

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Re: Hermeus hypersonic plane
« Reply #64 on: 08/16/2023 04:00 pm »
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.

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?

No, it doesn't.  They just picked the cheapest and available engines.

Offline jdon759

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Re: Hermeus hypersonic plane
« Reply #65 on: 07/25/2024 12:27 am »
What are the differences in approach to precoolers for Hermeus vs Reaction Engines?  (If anyone knows)
Where would we be today if our forefathers hadn't dreamt of where they'd be tomorrow?  (For better and worse)

Offline Spiceman

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Re: Hermeus hypersonic plane
« Reply #66 on: 07/25/2024 05:28 am »
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.
« Last Edit: 07/25/2024 11:32 am by Spiceman »

Offline Asteroza

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Re: Hermeus hypersonic plane
« Reply #67 on: 07/25/2024 07:07 am »
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...

Offline CameronD

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Re: Hermeus hypersonic plane
« Reply #68 on: 07/25/2024 11:13 pm »
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...

You have two choices: the fuel or the oxidiser.  To have to handle any other cryogen only adds weight and complexity and for that reason makes absolutely no sense.
With sufficient thrust, pigs fly just fine - however, this is not necessarily a good idea. It is hard to be sure where they are
going to land, and it could be dangerous sitting under them as they fly overhead.

Offline StraumliBlight

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Re: Hermeus hypersonic plane
« Reply #69 on: 09/13/2024 04:08 pm »


Quote
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.

 

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