Their parallax website is pretty entertaining... https://boomsupersonic.com/xb-1/build
Nice, anyone have some suggestions for quick ways to build parallax sites like this? Like themes, frameworks etc
Boom supersonic jet readies for rollout
161–170 of 283 posts
Re: Boom supersonic jet readies for rollout
#162Earlier quoted context omitted.
They are also working on a deal to use carbon neutral fuel from a company called Prometheus https://www.prometheusfuels.com/
Tried to read their FAQ but it is sort of handwavy. Do you have any links on the research behind this tech? I understand it uses CO2 from the atmosphere and solar + wind to build hydrocarbons? But what are the technical details there? How is this being done and why wasn't this done sooner?
Heaps of links in these comments: https://news.ycombinator.com/item?id=19842240
Re: Boom supersonic jet readies for rollout
#163If I recall correctly the Concorde used about 2 tonnes of fuel rolling on the ground alone.. I wonder how this new aircraft fares for fuel consumption? I believe the Concorde is a marvel. You could travel faster than the rotation of the earth in it! However I don’t think we need more environmentally unsustainable travel.
The reason for that is that the concorde used afterburners (basically, pump fuel into the high speed exhaust for extra thrust) which are incredibly inefficient. Great for a fighter jet where you need a sudden burst of extreme thrust, but not something you want a long-haul airliner to use. Boom uses turbofan engines to reach supersonic speeds which are much, much more efficient. In fact, many airliners could theoretic…
> The reason for that is that the concorde used afterburners (basically, pump fuel into the high speed exhaust for extra thrust) which are incredibly inefficient.
To put things in perspective, Concorde was using two Olympus engines designed originally in the 50s.
It was already a marvel that they can run for such a range at Mach 2.0 when designed 70 years ago.
A lot of things improved since. Most fighter jets can supercruise at supersonic speed without afterburners nowadays.
Re: Boom supersonic jet readies for rollout
#164Earlier quoted context omitted.
They are also working on a deal to use carbon neutral fuel from a company called Prometheus https://www.prometheusfuels.com/
Tried to read their FAQ but it is sort of handwavy. Do you have any links on the research behind this tech? I understand it uses CO2 from the atmosphere and solar + wind to build hydrocarbons? But what are the technical details there? How is this being done and why wasn't this done sooner?
Kerosene from fossil fuels is a lot cheaper than synthetic fuels.
Re: Boom supersonic jet readies for rollout
#165If I recall correctly the Concorde used about 2 tonnes of fuel rolling on the ground alone.. I wonder how this new aircraft fares for fuel consumption? I believe the Concorde is a marvel. You could travel faster than the rotation of the earth in it! However I don’t think we need more environmentally unsustainable travel.
The reason for that is that the concorde used afterburners (basically, pump fuel into the high speed exhaust for extra thrust) which are incredibly inefficient. Great for a fighter jet where you need a sudden burst of extreme thrust, but not something you want a long-haul airliner to use. Boom uses turbofan engines to reach supersonic speeds which are much, much more efficient. In fact, many airliners could theoretic…
> The reason for that is that the concorde used afterburners (basically, pump fuel into the high speed exhaust for extra thrust) which are incredibly inefficient.
Concorde didn't use afterburners "at speed". The afterburners were used for takeoff, and to go through the mach wall.
Concorde burned insane amounts of fuel on the ground because turbojets are very inefficient at low-speed. Not unlike the SR-71's really (though the SR-71 also had such extreme high-speed bypass it was basically using ramjets at speed).
Re: Boom supersonic jet readies for rollout
#166Earlier quoted context omitted.
The Boom plans to land at 185 knots/213MPH, comparable to a 737-800. They probably need a fraction of the distance to stop though, since the plane has about 1/3 of the seating capacity.
Wouldn't be so sure. Stopping depends mainly on how good the thrust reversers are. Wheel brakes will only take you so far (and being lighter doesn't meaningfully help you.. lighter weight means less traction.
Airliners are required to be able to land with reverse-thrust inoperative: reversers are useful for shorter taxi times and reducing brake wear but they aren't essential.
Re: Boom supersonic jet readies for rollout
#167Real question: have we solved the radiation problem yet? The concord's solution was to sample exposure with a cockpit Geiger counter and descend to 40kft if things got too hot.
This is an issue of altitude, not speed. If the Concorde’s solution was to fly at a lower altitude, I know of no reason that wouldn’t be possible for other supersonic craft.
Re: Boom supersonic jet readies for rollout
#168From my understanding a big problem with Concorde was the sonic boom which happened near takeoff and bothered urban residents. I've always wondered why they can't fly at normal airline speeds until over a rural area or an ocean before accelerating to sound barrier speeds.
> I've always wondered why they can't fly at normal airline speeds until over a rural area or an ocean before accelerating to sound barrier speeds.
Because geometry and engines which are efficient at very high speed are extremely inefficient at low speeds, so you want to avoid subsonic flight as much as possible.
Variable geometry (mostly variable-sweep wings) bridge that issue, but they're weak points, and significantly increase the weight and complexity of the machine, to the extent that Boeing's competitor SST (the 2707) abandoned variable-geometry mid-project as way too heavy and still not efficient enough, reverting to a more classic fixed delta.
Re: Boom supersonic jet readies for rollout
#169Earlier quoted context omitted.
In particular the sonic boom. There are ways to reduce that and they are trying to.
It's interesting... you'd think the military would have gone down this path already, and perhaps came up short? The ability to fly supersonic NOE (Nap-of-the-Earth) into enemy territory without leaving a trail of very loud sonic booms seems like it would be something of interest. B1-B Lancer's exist to do exactly this, but are quite noisy. Which either means I'm wrong and the military doesn't care about being quiet,…
> The ability to fly supersonic NOE (Nap-of-the-Earth) into enemy territory without leaving a trail of very loud sonic booms seems like it would be something of interest. B1-B Lancer's exist to do exactly this, but are quite noisy.
Wikipedia claims B-1B max speed at low altitude is Mach 0.96. High speed flight at low altitude consumes fuel like crazy due to the high density atmosphere.
Re: Boom supersonic jet readies for rollout
#170Earlier quoted context omitted.
You would leave a long trail of broken windows and reports from the moment you went supersonic in their territory, charting your trajectory. Threat detection is a network, not a single point. However, if you're moving fast enough and the target is close enough, your premise is valid. They would not have time to react. Cruise missiles tend to be used for those mission profiles.
Has it perhaps occured to any of you that flying at below radar altitude at supersonic or above speeds, would be dangerous and would have no benefit? If the enemy doesn't know you're there, you don't need to go fast.
Actually the US Air Force has had a period where NOE was used after rivals had operational high-altitude SAMs.
The current doctrine is to spend billions for radar-absorbing aircraft.