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Boom Supersonic to break sound barrier during historic test flight today

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Re: Boom Supersonic to break sound barrier during historic test flight today

#111

Post by notahacker »

agloe_dreams wrote: post #59
kachapopopow wrote: post #3

[flagged]

This whole 1% focus is just silly. The Concorde was expensive because everything around it was expensive, not just the nature of high speed flight. They built 20 planes total and never actually capitalized on large scale cost savings. The planes also used afterburner and burned a ton of fuel doing it. There is nothing stopping current transcontinential flights from being supersonic. Heck, the time savings can lead to…

> They built 20 planes total and never actually capitalized on large scale cost savings.

They never capitalized on large scale cost savings because there was no demand for large scale operation: most of the planes built were given away at nominal fees!

Boom's stated intent is to enable the aircraft to be profitable at business/first class prices, which is absolutely targeting the 1%. The engine will have better fuel efficiency than Concorde's afterburner-supported turbojet but that isn't saying much, and everything else about the operating economics (small capacity for long haul to major airports, niche type rating, clean sheet airframe and engine design from new OEM hoping to amortise development costs over a relatively small production run) screams expensive

Re: Boom Supersonic to break sound barrier during historic test flight today

#112

Post by rockemsockem »

kachapopopow wrote: post #73
rockemsockem wrote: post #39

Earlier quoted context omitted.

Are you unfamiliar with the work NASA is doing on sonic boom reductions? Or are you too cynical to care?

Very familiar, but even regular planes are loud as hell already since I happen to live between the airport and a holdover route.

Idk what altitude planes are at in a location like yours, but there is certainly going to be an altitude limit on supersonic flight over land.

Re: Boom Supersonic to break sound barrier during historic test flight today

#113

Post by rockemsockem »

kachapopopow wrote: post #58
rockemsockem wrote: post #43

Earlier quoted context omitted.

Large????

I'm assuming large here because that's what the tickets will cost for super sonic flight.

You have no reliable way to project the cost of supersonic flight 50 years in the future. It will come down. That's all I'm certain of.

I'm sure people told the Wright brothers similar things. You're simply being extremely short-sighted. Which is very ironic since you're also talking about climate change concerns around this post.

Re: Boom Supersonic to break sound barrier during historic test flight today

#114

Post by K0balt »

mmustapic wrote: post #95
JumpCrisscross wrote: post #57

Earlier quoted context omitted.

> Supersonic flight will never be more efficient than traditional flights Efficient by what metric? Fuel use? That’s the new master of our existence, our six-proton czar? If there is one way to kill sympathy and support for climate-change action, it’s by not only insisting but actually hoping that living standards don’t improve (or regress) because it reduces emissions. Instead of seeing a new super-premium air-trave…

> Efficient by what metric? Fuel use? That’s the new master of our existence, our six-proton czar? If it can be cheap at supersonic speeds, it will be much cheaper at subsonic, always. And use less fuel. The only advantage you get is speed.

Umm, this is not true. Supersonic speeds allow higher altitudes, which allows for higher efficiencies. This of course only applies if the aircraft is designed to take advantage of this, but I’m sure this one will be.

The limiting speed of subsonic aircraft is Mach .96 approximately.

For the u2, at its cruise altitude, this means about 100mph of airspeed… barely above its stall speed.

But if you go supersonic, you can break through that barrier and make use of the fact that there is much less air resistance at those altitudes. Not only that, but by riding past your shockwave, you can pick up a bit of recovered energy.

In some corners of the envelope, supersonic actually uses less fuel for the trip than Mach 0.9ish travel - which is where we fly our jetliners.

Also, we nasa has been experimenting with aerodynamic shapes that all but eliminate the sonic boom effect.

It’s not all bad.

Re: Boom Supersonic to break sound barrier during historic test flight today

#115

Post by hollerith »

K0balt wrote: post #114
mmustapic wrote: post #95

Earlier quoted context omitted.

> Efficient by what metric? Fuel use? That’s the new master of our existence, our six-proton czar? If it can be cheap at supersonic speeds, it will be much cheaper at subsonic, always. And use less fuel. The only advantage you get is speed.

Umm, this is not true. Supersonic speeds allow higher altitudes, which allows for higher efficiencies. This of course only applies if the aircraft is designed to take advantage of this, but I’m sure this one will be. The limiting speed of subsonic aircraft is Mach .96 approximately. For the u2, at its cruise altitude, this means about 100mph of airspeed… barely above its stall speed. But if you go supersonic, you can…

>nasa has been experimenting with aerodynamic shapes that all but eliminate the sonic boom effect.

Yes, they've been trying to do that since the 1960s. I haven't seen any signs that they've been what I would call successful.

Re: Boom Supersonic to break sound barrier during historic test flight today

#116

Post by K0balt »

hollerith wrote: post #115
K0balt wrote: post #114

Earlier quoted context omitted.

Umm, this is not true. Supersonic speeds allow higher altitudes, which allows for higher efficiencies. This of course only applies if the aircraft is designed to take advantage of this, but I’m sure this one will be. The limiting speed of subsonic aircraft is Mach .96 approximately. For the u2, at its cruise altitude, this means about 100mph of airspeed… barely above its stall speed. But if you go supersonic, you can…

>nasa has been experimenting with aerodynamic shapes that all but eliminate the sonic boom effect. Yes, they've been trying to do that since the 1960s. I haven't seen any signs that they've been what I would call successful.

The x59 would have a thing or two to say about that. The sound pulse at ground level with the aircraft at altitude is about the same as a dishwasher, below the level of street traffic.

Re: Boom Supersonic to break sound barrier during historic test flight today

#117

Post by ls612 »

zhoujianfu wrote: post #83
DanielHB wrote: post #70

As someone who travels cross-atlantic semi-occasionally my price threshold for a 50% shorter flight is 25% increased cost. This is coming from a relatively well off middle-aged software engineer. It is hard to think that this tech will ever be common besides a few "high status" (NY->London) routes like the concord was. It is my understanding that fuel costs increase as speed increases so there is no way this could ev…

I believe boom has suggested it would only cut about 30% of the time off, and cost 3x.. not to mention needing to refuel to cross the pacific. :/

CONUS -> Honolulu -> East Asia or Australia will be a very viable setup. Especially if the refueling stop in Hawaii is well optimized for speed.

Re: Boom Supersonic to break sound barrier during historic test flight today

#118

Post by matheweis »

crowcroft wrote: post #105

What engines are they using? I thought Boom was having to develop their own engines after everyone else pulled out, but assuming they haven't built their own functional supersonic engine yet?

The XB-1 prototype is powered by three General Electric J85 engines; mentioned in this writeup: https://boomsupersonic.com/flyby/xb-1-pilot-profile-tristan-...

Re: Boom Supersonic to break sound barrier during historic test flight today

#119

Post by mmustapic »

K0balt wrote: post #114
mmustapic wrote: post #95

Earlier quoted context omitted.

> Efficient by what metric? Fuel use? That’s the new master of our existence, our six-proton czar? If it can be cheap at supersonic speeds, it will be much cheaper at subsonic, always. And use less fuel. The only advantage you get is speed.

Umm, this is not true. Supersonic speeds allow higher altitudes, which allows for higher efficiencies. This of course only applies if the aircraft is designed to take advantage of this, but I’m sure this one will be. The limiting speed of subsonic aircraft is Mach .96 approximately. For the u2, at its cruise altitude, this means about 100mph of airspeed… barely above its stall speed. But if you go supersonic, you can…

> I’m sure this one will be.

If they are planning to make it more efficient than subsonic trips, it would be the first thing you would see in the website, or at least the FAQ. Supersonic flight is very cool, but for me this is just like Bugatti announcing a faster car for the rich, or an airline showing its first class luxury cabin: not very interesting.

Re: Boom Supersonic to break sound barrier during historic test flight today

#120

Post by K0balt »

mmustapic wrote: post #119
K0balt wrote: post #114

Earlier quoted context omitted.

Umm, this is not true. Supersonic speeds allow higher altitudes, which allows for higher efficiencies. This of course only applies if the aircraft is designed to take advantage of this, but I’m sure this one will be. The limiting speed of subsonic aircraft is Mach .96 approximately. For the u2, at its cruise altitude, this means about 100mph of airspeed… barely above its stall speed. But if you go supersonic, you can…

> I’m sure this one will be. If they are planning to make it more efficient than subsonic trips, it would be the first thing you would see in the website, or at least the FAQ. Supersonic flight is very cool, but for me this is just like Bugatti announcing a faster car for the rich, or an airline showing its first class luxury cabin: not very interesting.

I agree that this particular aircraft / project has limited potential. What I am most excited about is the potential for advancement of the field that could lead to realizing the potential benefits in supersonic transport.

It’s like props vs jets. Jet aircraft were less efficient but faster… until the altitude benefits made them more efficient and faster. Flying at the edge of space is the next step in that speed/ efficiency curve, and that is necessarily supersonic.

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