Boom Supersonic Overture M1.8 SST

[TomcatViP]

That isn't a smoke generator at the wing tip, it's an exciter so they can test for flutter at lower speeds by exciting the wing for how it would react at higher speeds. It allows for a safer expansion of the flutter envelope.

That is correct.

This detail being revealed recently by Boom in their press briefing.

 

[TomcatViP]

Those aren't the tufts either, those are the pieces of tape holding the tufts (tufts are visible in a hi-res photo). If those were the tufts, they'd be indicating world-beating span-wise flow.(Which is what I first thought!)

I have no more that Falcon eyesight but still I can see some of them enough to have placed my earlier comment

It would be nice not be taken for an imbecile at face value.

And some updated graphics from link in post below:

 

[Flyaway]

View: https://www.youtube.com/watch?v=lQvQsvD4Ykw

The first ever look into Boom Supersonic, captured during last Friday's XB-1 flight 3 on S3. Get an up close look at XB-1, the moments before takeoff, and test pilot "Geppetto" re-opening the cockpit and sharing his unfiltered thoughts with Blake right after flight.

 

[aim9xray]

It would be nice not be taken for an imbecile at face value.

No disrespect was intended, my apologies. I made the imbecilic assessment at first, scratched my head, researched it, and thought I might share with others who might have the same initial misapprehension as I.

 

[Sundog]

Those aren't the tufts either, those are the pieces of tape holding the tufts (tufts are visible in a hi-res photo). If those were the tufts, they'd be indicating world-beating span-wise flow.(Which is what I first thought!)

I was going on what Blake Scholl, the head of Boom posted on Twitter. But with the tufting, smoke generators do make more sense.

 

[Scott Kenny]

Sure, but you could add an afterburner or cold stream burner for acceleration and then cruise supersonically more efficiently than with a smaller bpr like the F119. Of course you would have to integrate the larger fan into aircraft structure.

Oh, absolutely you could add an afterburner or PCB/cold stream burner to get supersonic. But even the mighty Blackbird (all hail the king of speed!) needed a small dive to break Mach 1 with the afterburners lit. So there's no huge reason to add the afterburners to a design if they don't give you massive acceleration. Just dive from 40k to 30k and then level out and climb back up once supersonic.

 

[Basil]

Oh, absolutely you could add an afterburner or PCB/cold stream burner to get supersonic. But even the mighty Blackbird (all hail the king of speed!) needed a small dive to break Mach 1 with the afterburners lit. So there's no huge reason to add the afterburners to a design if they don't give you massive acceleration. Just dive from 40k to 30k and then level out and climb back up once supersonic.

I was thinking of a military application of the "Symphony" engine. Depending on the situation and mission you sometimes want sudden acceleration without a dive. The SR-71 did the dive to preserve fuel for the reconnaissance mission.

 

[Scott Kenny]

I was thinking of a military application of the "Symphony" engine. Depending on the situation and mission you sometimes want sudden acceleration without a dive. The SR-71 did the dive to preserve fuel for the reconnaissance mission.

I'm not really seeing a military application for the engine, barring a slower blackbird or maybe a really large cruise missile (Hound Dog or SLAM sized).

It's just going to be a weird engine. Massively flat-rated so that it's not too loud on takeoff and with a really low OPR for supercruising.

 

[Basil]

I'm not really seeing a military application for the engine, barring a slower blackbird or maybe a really large cruise missile (Hound Dog or SLAM sized).

It's just going to be a weird engine. Massively flat-rated so that it's not too loud on takeoff and with a really low OPR for supercruising.

In case the engine is ever realized and works as proposed - I can imagine there would be several military applications for an efficient Mach 1,5 (or so) supercruise off-the-shelf propulsion system.

 

[Basil]

Some - related to this topic - considerations regarding civil supersonic propulsion - excellent by Bjorn as always:

Bjorn’s Corner: Supersonic transport revival, Part 10 - Leeham News and Analysis

October 12, 2018, ©. Leeham News: In the last Corner we discussed the challenges of the nacelle outlet for an SST (SuperSonic Transport). Now we will discuss SST engines and what are the key technical challenges for these... Read More

leehamnews.com

Perhaps we should move this to the Propulsion Section.

 

[NMaude]

cold stream burner

Are they like the front-nozzle plenum burners for the BS100 engine designed for the aborted HS P.1154?

 

[Kiltonge]

For comparison, tufting on the wing of a Skylancer ( NASA TN D-3071 ):

https://ntrs.nasa.gov/api/citations/19660003728/downloads/19660003728.pdf

The XB-1 appears much better.

 

[F119Doctor]

Some - related to this topic - considerations regarding civil supersonic propulsion - excellent by Bjorn as always:

Bjorn’s Corner: Supersonic transport revival, Part 10 - Leeham News and Analysis

October 12, 2018, ©. Leeham News: In the last Corner we discussed the challenges of the nacelle outlet for an SST (SuperSonic Transport). Now we will discuss SST engines and what are the key technical challenges for these... Read More

leehamnews.com

Perhaps we should move this to the Propulsion Section.

Bjorn is correct in stating that compressor exit temperature T3 can be a limiting factor, just like turbine rotor inlet temperature T4.1, low rotor speed N1, and high rotor speed N2.

The response of the engine control system when reaching one of these limits is to stop increasing core fuel flow, or reduce fuel flow as necessary to keep at or below the limit. This reduces the aerodynamic rotor speed of the engine, reducing airflow, pressure ratio, and thrust. In supersonic flight, increasing inlet temperature with increasing Mach number causes all these parameters to increase until one of them hits its limit (called the Theta break), with increasing inlet temperature causing loss of engine performance beyond that point. The total propulsion system performance can continue to increase with inlet ram recovery multiplying the engine pressure ratio for greater nozzle pressure ratio, but the engine contribution decreases beyond that limit condition.

 

[TomcatViP]

And what about having a blown fan instead

 

[Scott Kenny]

In case the engine is ever realized and works as proposed - I can imagine there would be several military applications for an efficient Mach 1,5 (or so) supercruise off-the-shelf propulsion system.

Maybe? Most of the solid military supercruise applications seem to be either higher speeds (Blackbird) or need fighter performance.

Maybe a slower recon drone? I dunno.

Are they like the front-nozzle plenum burners for the BS100 engine designed for the aborted HS P.1154?

That is how I'm picturing it, yes. Just less weird/complicated plumbing upstream of them than needed to get the combustion happening in the corner in the BS100. Because there's no "corner" in the bypass ducts here.

Bjorn is correct in stating that compressor exit temperature T3 can be a limiting factor, just like turbine rotor inlet temperature T4.1, low rotor speed N1, and high rotor speed N2.

The response of the engine control system when reaching one of these limits is to stop increasing core fuel flow, or reduce fuel flow as necessary to keep at or below the limit. This reduces the aerodynamic rotor speed of the engine, reducing airflow, pressure ratio, and thrust. In supersonic flight, increasing inlet temperature with greater speed causes all these parameters to increase until one of them hits its limit (called the Theta break), with increasing inlet temperature causing loss of engine performance beyond that point. The total propulsion system performance can continue to increase with inlet ram recovery multiplying the engine pressure ratio for greater nozzle pressure ratio, but the engine contribution decreases beyond that limit condition.

Probably the very best example of this is the Blackbird, where at Mach 3 the engine was said to be dragging on the mounts (producing negative net thrust!) and the inlet and afterburner+ejector were making all the thrust to drive the plane at cruise.

 

[NMaude]

and the inlet and afterburner+ejector were making all the thrust to drive the plane at cruise.

That's why the J-58 is referred to as a turbo-ramjet.

 

[NMaude]

Scott Manley has just uploaded a video concerning Boom Aerospace's XB-1:

Boom Aerospace was founded 10 years ago with the ambitious goal of developing a supersonic passenger airliner. While Concorde was a commercial failure despite being a technological marvel, Boom believes that there's enough demand for supersonic passenger capability that there's a market worth addressing.

Right now the aircraft they have flying is a much smaller test aircraft - the XB-1 - a 3 engine supersonic jet intended to demonstrate some important new technologies and help the company acquire the skills needed to build the larger Overture passenger airliner.

https://boomsupersonic.com/

 

[TomcatViP]

Camera on the nose gear: how do they land with the gear up? If they have a malfunction here (not uncommon with an exp a/c) , the plane is at risk of a loss. I would have though that camera were affix to the fuselage.

 

[Moose]

With that schnoz I don't think trying a landing without a nose gear would be very appealing, but if they do decide to try it they'd likely use the chase pilot of coach the demonstrator in.

 

[Scott Kenny]

With that schnoz I don't think trying a landing without a nose gear would be very appealing, but if they do decide to try it they'd likely use the chase pilot of coach the demonstrator in.

Plus, with the size of the aircraft and guesstimated weight, you could legitimately have a mechanical extension instead of hydraulic. Or mechanical emergency extension instead of hydraulic.

 

[TomcatViP]

With that schnoz I don't think trying a landing without a nose gear would be very appealing, but if they do decide to try it they'd likely use the chase pilot of coach the demonstrator in.

Yes for the chase. Yes (they have also) for the LSO. But why would you deprive yourself of frwd vision for such low volume sensors?

@Scott Kenny : MLG retracts rearward. Front, forward.

Remember that there is no ejection seat. Any failure is a risk of loss of life.

 

[TomcatViP]

Test flight 4 as viewed from the cockpit, with Radio chats and off camera post flight comments.
Some here would be interested with the flutter test done with the external actuator, wingtips mounted, that experienced a failure during the test (just where the video below starts):

View: https://youtu.be/dAYEHuC0NgE?t=289

Enjoy!

 

[Scott Kenny]

Not gonna lie, the XB-1's shape is growing on me. Reminds me of an A5, especially the Vigilante interceptor version with triple engines.

 

[Hydroman]

Hopefully there will be more video updates showing the progress of XB-1. At least Boom is going about this in a logical development manner, cheers to Boom. On the other hand, Aerion was joke from the beginning, was just a money pit and an enrichment scheme for the main players.

 

[Sundog]

I think they said the next flight might be tomorrow (10-07-24). They're planning on expanding the envelop to M=.75.

 

[Archibald]

Hopefully there will be more video updates showing the progress of XB-1. At least Boom is going about this in a logical development manner, cheers to Boom. On the other hand, Aerion was joke from the beginning, was just a money pit and an enrichment scheme for the main players.

Be careful what you wish for: Boom XB-1 might be used as a "money magnet" when showed at air shows. For the same purpose as Aerion in the end. "Look, at least we have build that wonder plane."
(half joking)

 

[TomcatViP]

XB-1, on contrary to the plethora of Frankenstein prototypes churned out by other Startups, is certainly the least of them that can be called a trick. There is some points that are contestable, but at least the quality is on par with the best entrants of the aerospace industry before them.

 

[Dynoman]

Test flight 4 as viewed from the cockpit, with Radio chats and off camera post flight comments.

Hopefully, Boom continues to provide video from the cockpit and ops during flight test. This is an excellent opportunity to showcase private industry's ability to design, develop, and test advanced aircraft designs free of USAF, Navy, NASA, and other government entities.

 

[Kiltonge]

Hopefully, Boom continues to provide video from the cockpit and ops during flight test. This is an excellent opportunity to showcase private industry's ability to design, develop, and test advanced aircraft designs free of USAF, Navy, NASA, and other government entities.

Is it really any more advanced than the designs that the big bizjet manufacturers produce? A Global 8000 will sit happily at M0.94 for hours on end and it does it through aerodynamics, not thrust.

 

[Dynoman]

Is it really any more advanced than the designs that the big bizjet manufacturers produce?

Designing a supersonic aircraft is significantly harder than designing a transonic aircraft because supersonic flight introduces complex aerodynamic challenges, including high drag, shockwave management, and extreme heat generation, requiring specialized materials and advanced design techniques that are not needed for transonic flight; essentially, the physics of air at supersonic speeds are much more demanding to work with than at transonic speeds. And from a cost perspective, typically incremental increases in performance result in exponential costs in development. This has been a problem for Sukhoi, Aeronjet, and Gulfstream to move their supersonic bizjet ideas forward. Its exciting to see these developments at Boom, especially for a company that was created in 2014, developed a design in 2016, and are flying a supersonic prototype in 2024, all with private equity.

 

[Hydroman]

Be careful what you wish for: Boom XB-1 might be used as a "money magnet" when showed at air shows. For the same purpose as Aerion in the end. "Look, at least we have build that wonder plane."
(half joking)

I agree Archibald but at least Boom actually built a technology demonstrator and time will tell at least if the potential customers stay the course. As a note, I knew and had worked with some of the guys in the Aerion executive hierarchy at NGC and I am disappointed at what Aerion really was.

 

[Halcyon66]

Here we go again...............

Venus Stargazer M4 Hypersonic

View: https://www.youtube.com/watch?v=kmzGfU2U_b8


Regards,

 

[4decaa]

Venus Stargazer M4 Hypersonic

from the description:

Stargazer M4 is Earth’s first hypersonic, reusable aircraft. No one has ever built an engine that makes two-hour global transport cost-effective. Until now.

Built, you say?

 

[Halcyon66]

Do the flashy video and then hold out your hand for the $$$, start burning through the cash and then hold out your hand again.

Never ends.

Boom is going to need so much money going forward, the returns if they ever get anything in the air will be extremely low.

Anything airline these days is a race to the bottom, $500 for all you can fly in a year, over 7 hours in new configurations whereas no meals/reduced legroom.

You can see where the industry is going. Even if you can get from A to B in 15 minutes you still spend 3 hours each end at the airport

Regards,

 

[Scott Kenny]

Do the flashy video and then hold out your hand for the $$$, start burning through the cash and then hold out your hand again.

Never ends.

Boom is going to need so much money going forward, the returns if they ever get anything in the air will be extremely low.

Anything airline these days is a race to the bottom, $500 for all you can fly in a year, over 7 hours in new configurations whereas no meals/reduced legroom.

You can see where the industry is going. Even if you can get from A to B in 15 minutes you still spend 3 hours each end at the airport

Regards,

They've at least put a lot of money where their mouth is in terms of having a flying airframe. Yes, it doesn't resemble their current intended design, but it allows them to check the prototype performance against the computer models.

Which is a long way ahead of even Gulfstream and Sukhoi supersonic bizjets!

 

[Halcyon66]

So does NASA in the X-59, you can actually do more in the modelling these days without actually building anything.

The engine side will kill them you don't even have the largest aircraft companies making their own engines.

15 years ago, was in talks with a start-up SSBJ company as they were looking for funding and they had come up with a "new" engine design.

They talked billions of $$ with abandon like it was nothing, they finally abandoned the project.

They are still trying to get something going but money is not free anymore.

Regards,

 

[Scott Kenny]

So does NASA in the X-59, you can actually do more in the modelling these days without actually building anything.

You still need to verify the model.

Which is what Boom is doing right now.

 

[Halcyon66]

Correct, yet they are not verifying the actual end use airframe, they are verifying a single seat aircraft that has little in common with a 60 to 80 seat airframe.

They don't really have an actual final design only a concept of Overture. Doing the small steps with a single seat airframe just keeps them in the news and never-ending funding rounds.

You want to test the proposed airframe they have CFD/FEA and supersonic wind tunnels that they could easily test sub-scale models with very accurate results.

Yet as they don't have the final design or engines what is the point?

The others you did speak about did actually have the end designs and the numbers worked out yet realised they are going to cost billions and walked away.

Boom is thinking $5,000 for a New York-to-London round-trip, while the same on Concorde cost $20,000 adjusted for inflation.

You cannot even a current business class seat for that on efficient big slow subsonic airliners.

As said the company that I was talking about had the airframe worked out and yet no engines.

Best to start with propulsion before anything.

Regards,

 

[TomcatViP]

Propulsion and costs, in the dozens of thousands dollars, are not really relevant while flights remain scarce. Customers will savagely piles up on the front desk of the first handful of companies that offer safe supersonic travel anyway.

The new engine should be seen only as being there to safeguard the business model* on the long term (pioneering is great but scaling-up is much better!).

*Well, at least, it's my analysis and personal opinion. I am not sure that this is shared by Boom.

 

[Flyaway]

https://twitter.com/x/status/1849985452004307421

View: https://twitter.com/boomaero/status/1849985452004307421

BREAKING: XB-1 successfully completed its sixth test flight and continues to gain altitude, approaching supersonic flight later this year.
New max altitude: 20,000 ft
Flutter excitation system (FES) test at Mach 0.65
Demonstrated successful FES operation in flight

XB-1 Flight Test Program Live Blog

On October 25, 2024, XB-1 successfully completed its sixth test flight and continues to make progress in expanding the envelope for supersonic flight.

Flight six primarily targeted flutter and handling qualities testing at a higher altitude than previous flights. The FES, or Flutter Excitement System, is crucial in testing new aircraft to ensure there are no undesirable interactions between the airflow around the vehicle and the structure of the aircraft. Flutter is a phenomenon where the energy from the airflow can interact with the airframe vibration modes and cause structural failure. Modern aircraft design uses tools and predictions to develop aircraft that should not be susceptible to flutter, which we verify with testing. In this flight, XB-1 made significant progress towards validating a fully functional FES system.

Unfortunately, we did experience a degradation in GPS signal strength which impacted our ability to accomplish more in this flight. The team is currently troubleshooting this issue and as soon as the source of interference is identified and corrected, we will be on to Flight 7.