151–160 of 283 posts
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.
From 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.
good supersonic performance and high subsonic efficiency are essentially opposing goals - a big wing that generates lots of lift is more efficient at slower speeds, but obviously becomes problematic at supersonic speeds. Also, drag is highest near the transsonic regime, and fuel burn is nonlinear, it's partially a function of time, so "getting there faster" can actually burn less fuel than having to run the engines for longer.
From 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.
If 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…
If 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…
Either way, it’s fairly obscene.
Earlier quoted context omitted.
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,…
Or maybe the military has technology we don't know about yet?
What advantage exactly does a B-1B have over a cruise missile? What advantage does it have over some UAVs sent on an autonomous mission? Bearing in mind that you can easily fire off a couple dozen cruise missiles just for the airframe cost of a B-1 let alone the training, etc.
A manned pilot is some better in some respects, but is it enough better to justify the additional cost, training, and the downsides that come along with a manned mission (political risk, etc)?
For certain missions, the B-2 and the B-52 etc have their merits, and close-air-support with a UAV in non-permissive airspace seems like a bad idea. But by and large the trend has been and continues to be using unmanned and expendable platforms to replace a lot of roles. The B-1 doesn't do anything that a cruise missile really cannot replace.
If 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.
They are also working on a deal to use carbon neutral fuel from a company called Prometheus https://www.prometheusfuels.com/
Earlier quoted context omitted.
Yeah, much more excited if there were talk of high-speed rail criss-crossing the U.S.
High-speed rail isn't high speed enough. Even with way faster than current tech and NO stops you'd still be looking at taking 12+ hours for what a plane can do in 5. That's ignoring the trillions it would cost. The US does not have the population density to make HSR viable.
Regionally it would make a ton of sense over absurdly short flights.
Most people are not flying LA to NYC so that is a minority use case anyways.
From 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.
The biggest time sink when traveling between continents is the jet lag. A faster jet doesn’t fix that, it only costs more and pollutes more.
The new 787 has made her lag a lot better with better air quality, timed, dimming cabin lights and a few other comfort trucks, it definitely takes the edge off.
Both the Boeing 787 and the Airbus A350 XWB have a lower (than previous airliners) cabin altitude of 1,800 m.
Note that some private jets do quite a bit better again: the Gulfstream G650 has ~1480 meters.