3 ms·
How is the fuel efficiency of these? They go faster, but I assume they would also fly higher where the air is thinner. Does it cancel out?
by HPsquared 4y ago
How is the fuel efficiency of these? They go faster, but I assume they would also fly higher where the air is thinner. Does it cancel out?
- akmarinov 4y agoAdding to the supersonic questions - how will they deal with the sonic booms? I assume they're still banned over land, which significantly adds to travel time?
- nradov 4y agoThey will deal with the sonic booms the same way that Condorde did: by flying over water.
- rflrob 4y agoThe routes they mentioned in the press release (NYC-LHR, LAX-Hawaii) are almost entirely over water.
- skellera 4y agoAs the press release says, it’s specifically designed to replace over water routes. There are many international routes (some domestic, like Hawaii) that this can handle. So it won’t be doing anything like LA->NY.
- cjrp 4y agoI wonder how noisy they are even sub-sonic. Concorde was so loud on takeoff and approach, you'd stop and look up even living ~20 miles away from Heathrow. If you tried to introduce that now, there's no way would it be accepted.
- zip1234 4y agoOld jet engines are super noisy. Modern jet engines are much much quieter.
- solardev 4y agoWhat makes the newer engines so much quieter?
- HPsquared 4y agoThey have larger fan blades, for one. That means they move a large volume of air relatively slowly, instead of a small volume of air moving quickly. Consider the difference between a large shop fan, and a small high pressure compressed air nozzle commonly used in workshops for cleaning, with both sized to give the same "reaction force" (i.e. the same thrust). The high-pressure nozzle makes much more noise.
- chasil 4y agoThe metallurgy of the fan blades has also vastly improved. Monocrystaline fan blades have very different material properties from the polycrystaline blades that (I am guessing) were used on Concorde. https://www.americanscientist.org/article/each-blade-a-single-crystal https://www.americanscientist.org/article/each-blade-a-singl...
- solardev 4y agoThanks for sharing that link! It's amazing what people were able to come up with in the 60s, before computers and Wikipedia and 3D modeling... wow. One of the patents mentioned is how VerSnyder was able to grow a turbine blade in a monodirectional crystalline structure: https://patents.google.com/patent/US3260505?oq=versnyder+1966 https://patents.google.com/patent/US3260505?oq=versnyder+196... just using a special mold and a specific alloy. That would later form the turbine blades of the SR-71 Blackbird.
- chasil 4y agoI just reread it. All of it was familiar, but I had forgotten a few of the details. The first monodirectional blades were introduced to commercial jet engines in 1974, so Concorde definitely did not have this technology with the original engines.
- zymhan 4y agoSince no engine for it exists yet, no one knows.
- peteri 4y agoFor concorde the numbers are quite different. Stealing from truly epic concorde thread on pprune. https://www.pprune.org/tech-log/423988-concorde-question.html https://www.pprune.org/tech-log/423988-concorde-question.htm... At the beginning of the take off roll, each engine would be burning around 21 tonnes/hour. Anyway, back to some figues; at Mach 2, 50,000', the typical fuel burn per engine would be around 5 tonnes/hour, falling to around 4.2 tonnes/hour at 60,000'