The point is that there won’t be any audible “sonic boom” anymore, and afterburning engines won’t be used, so the engine sound and fuel consumption will be less of an issue. Boom technologies flew a technology demonstrator, the XB-1, at supersonic speeds earlier this year without a sonic boom being audible at ground level. The aircraft flies at high altitude at low supersonic speeds (Mach 1.1-1.3 for the XB-1) and the sound waves from the sonic boom get diffracted back towards the horizontal by the warmer thicker air at lower altitudes, so there is no audible sonic boom at ground level. The phenomenon is called Mach cutoff. Flying at supersonic speeds without the use of afterburner to cruise or accelerate to supersonic speeds is called supercruise. The plan™ is to scale this technology up for larger aircraft, such as 50-100 seater passenger aircraft like the Boom Overture concept (does not exist yet outside of CGI rendering). Even low supersonic speeds would decrease in flight time significantly. Cruising at Mach 1.35 is 50% faster than cruising at Mach 0.9 for example.
Is this realistic and commercially viable? I don’t know, it seems very expensive for a few luxury fast flights. But the technology is there, as long as the financial backing is there (the biggest obstacle to viability), it’s technically possible. Supercuise and Mach cutoff solve two of the biggest issues commercial supersonic flight had previously with the Concorde. Comac in China wants to do something similar in the future. The question then becomes how much people are prepared to pay for 50% shorter flights, and how much the cost of supersonic flight has been reduced by improved technology.
The question then becomes how much people are prepared to pay for 50% shorter flights, and how much the cost of supersonic flight has been reduced by improved technology.
My main questions center on how much extra fuel is required to provide all that additional energy? Idk enough about fluid mechanics to answer this on my own: how much more energy does it take to accelerate from mach 1.1 to mach 1.2 vs mach 0.9 to mach 1.1?
it’s not acceleration, it’s air friction vs plane geometry, supersonic airflow has different optimal characteristics both for engines and flight surfaces/wings (naive kinetic energy is just differences of speed squared though).
But performing the Mach-cutoff flight “burns more fuel on the same distance than both subsonic and supersonic flight”, says Liebhardt. That makes it less economically viable than a regular supersonic flight and “the worst speed to fly at for fuel economy”. He sees Mach-cutoff flights as being more of a niche use case for “supersonic business jet users”, rather than for commercial airlines.
seems like they get shit of both worlds tbh with fuel economy (not zoomy enough to just cross distance fast with godawful fuel consumption/not optimized enough for flight at those speeds via engine regimes/geometry (that part might be fixable, but depends on how long it spends on subsonic climb/descend part of journey)
The point is that there won’t be any audible “sonic boom” anymore, and afterburning engines won’t be used, so the engine sound and fuel consumption will be less of an issue. Boom technologies flew a technology demonstrator, the XB-1, at supersonic speeds earlier this year without a sonic boom being audible at ground level. The aircraft flies at high altitude at low supersonic speeds (Mach 1.1-1.3 for the XB-1) and the sound waves from the sonic boom get diffracted back towards the horizontal by the warmer thicker air at lower altitudes, so there is no audible sonic boom at ground level. The phenomenon is called Mach cutoff. Flying at supersonic speeds without the use of afterburner to cruise or accelerate to supersonic speeds is called supercruise. The plan™ is to scale this technology up for larger aircraft, such as 50-100 seater passenger aircraft like the Boom Overture concept (does not exist yet outside of CGI rendering). Even low supersonic speeds would decrease in flight time significantly. Cruising at Mach 1.35 is 50% faster than cruising at Mach 0.9 for example.
Is this realistic and commercially viable? I don’t know, it seems very expensive for a few luxury fast flights. But the technology is there, as long as the financial backing is there (the biggest obstacle to viability), it’s technically possible. Supercuise and Mach cutoff solve two of the biggest issues commercial supersonic flight had previously with the Concorde. Comac in China wants to do something similar in the future. The question then becomes how much people are prepared to pay for 50% shorter flights, and how much the cost of supersonic flight has been reduced by improved technology.
My main questions center on how much extra fuel is required to provide all that additional energy? Idk enough about fluid mechanics to answer this on my own: how much more energy does it take to accelerate from mach 1.1 to mach 1.2 vs mach 0.9 to mach 1.1?
it’s not acceleration, it’s air friction vs plane geometry, supersonic airflow has different optimal characteristics both for engines and flight surfaces/wings (naive kinetic energy is just differences of speed squared though).
from new scientist
seems like they get shit of both worlds tbh with fuel economy (not zoomy enough to just cross distance fast with godawful fuel consumption/not optimized enough for flight at those speeds via engine regimes/geometry (that part might be fixable, but depends on how long it spends on subsonic climb/descend part of journey)
oh that makes so much sense thank you!