Tech Tuesday 11/15/18 “Lucy, The Sky Is Diamonds” Edition
[TT1] Boeing hangs the biggest turbofan to date on the 777X prototype. To give that some perspective, the engine is about the same width as the fuselage of a 737. Boeing is also showing off it’s ideas for a new transonic wing (a wing designed to cruise in the transonic range, ~Mach 0.8 – Mach 0.95). The challenge of transonic cruise is that it guarantees that some parts of the aircraft will experience supersonic airflow, while others are still subsonic. Any flow that goes supersonic results in shocks that impact performance and fatigue life, requiring that the design account for that. Long, thin wings are ideal for those cruise conditions, but a simple cantilevered wing that long and thin requires a lot of additional structure (read: weight). The trussed wing gives additional lifting area and support, negating the bulk of the weight penalty. From an Aviation Week article (login required):
The junction with the fuselage has been moved back and the main truss now angles up to meet the wing at some distance from the fuselage, presumably to reduce aerodynamic interference. There is a small jury member connecting the truss to the wing close to its junction with the wing.
The long-span wing folds just outboard of the truss junctions to enable the TTBW to use the same airport gates as a 737, which has a wing span of almost 118 ft.
The aircraft pictured appears to be conventionally powered, with turbofans mounted under the wing, but NASA is studying versions of the TTBW concept with hybrid-electric propulsion. These have electric motors integrated into the turbine engines. An electric-powered ducted thruster on the tail ingests the fuselage boundary layer and reenergizes the wake, reducing drag and energy consumption.
[TT2] Not to let Boeing have all the attention, Airbus is working on a “helicopter” that it thinks could hit 400 kph.
[TT3] Bell is putting it’s toes into the whole air taxi business. Once upon a time, Bell was hoping to market a civilian version of the V-22 Osprey or the V-280 Valor for urban air ferry services. Not sure if that is still a plan.
[TT4] LG says it has a production ready rollable OLED TV. This is not a big screen OLED on a rolling cart, it’s an OLED screen that can roll up like a newspaper for out of sight storage in a media cabinet or credenza.
[TT5] Ford says no to Wi-Fi, yes to 5G. Hammering out these kinds of protocols is kinda crucial to the development of fully-, or even semi-autonomous vehicles.
[TT6] The UK is testing a new kind of communications satellite, one that can be modified and reprogrammed while in orbit.
[TT7] China’s Far Side probe carried an extra antenna on it’s trip around the bend, one that will be able to listen to radio signals we haven’t really gotten to listen to since the 70’s. Also in radio-astronomy, the Canadians have a new telescope called CHIME (seriously, do people honestly brainstorm names that make handy acronyms?). Not only will CHIME help investigate the phenomena known as Fast Radio Bursts, it already answered one big question about them while it was basically booting up.
[TT8] Ya know how our ancestors thought the stars in the sky were gemstones in the firmament. About that…
[TT9] Stellar Cow gives birth to a black hole, or a neutron star. We think.
[TT10] Finally, we have a lead on why fake news propagates so readily. It’s the Boomers fault.
[TT11] A steam powered spacecraft. Call me skeptical. Intrigued, but skeptical.
[TT12] Broad spectrum Ebola protection in one single dose. That’s pretty fecking awesome.
So many questions and thoughts today…
TT[1-3]: I’m assuming these are all things that are possible now because of high-strength composites and glue. You know you’re old when it bothers you to think about just how much of the airliner you’re on is glued together rather than bolted or riveted.
TT4: I started following OLEDs professionally 20 years ago. It has taken a disappointingly long time for the vendors to solve the last few engineering problems.
TT6: What does it say that when I read a different article about this satellite last week, my first thoughts were, “How long would the approval process at the FCC (or European equivalent) and the ITU take to get an operating license for the use of different frequencies? Does Brexit mean that Parliament will have to create and fund a whole new agency for space things?”
TT10: Of course it is. It’s always our fault. Reminds me of the time in graduate school when a woman told me I personally was responsible for 90% of the evil in the world.
TT11: When in doubt, always check to see if Heinlein invented it first. He had spacecraft that used steam as reaction mass, heated to very high temperatures by passing through a nuclear reactor. IIRC, nuclear thermal rockets, at least on paper, are about twice as efficient as chemical rockets.Report
Your first comment reminded me of an old guy at Bell that I worked with way back when I was a new engineer. He insisted on referring to composites (my specialty) as ‘string and glue’. It was all in good fun though. He was a bright guy and understood the benefits, especially in terms of strength and fatigue life, but always tried to get a rise out of the composites guys with that.Report
To be perfectly honest, I don’t really worry that much about the composites and glue. I worry more about the fact that there’s real-time software doing much of the actual decision-making. I’ve written real-time software, and read other people’s. Most real-time programmers aren’t nearly paranoid enough to suit me.Report
It’s a good day when Mike finds more than one thing to comment on!
TT1-3: The composites and epoxy are truly stronger than steel and more resistant to fatigue than other metals, for the weight. What’s interesting is that regulators around the world, and older school engineers, are still figuring out how to analyze and certify composite structures that are designed to maximally leverage the properties of the composites. By that, I mean that often enough, the composite material is treated like ‘black aluminum’, and shaped into traditional beams and shells that we know how to analyze really well. The more complex structures that composites should be formed into require complex computer models to properly analyze, and the old guard still doesn’t fully trust such analysis.
tl;dr – it’s not just you.
TT4: Which problems are you thinking of?
TT11 – I remember those stories.Report
The two biggies were the blue OLEDs and oxygen. At that time, blue OLEDs were only about half as bright as red and green devices, and running them at higher currents to make up for it shortened their usable lifetime by a lot. All of the compounds used for OLEDs break down fairly quickly in the presence of oxygen, so the screen material and coatings/sealants had to be completely impermeable to oxygen and water (as well as not outgassing any oxygen compounds). For plastics, this turns out to be a hard problem.
The question I was trying to answer at the time was “When will displays large enough that people will demand high definition content become standard issue?” That was an important question for cable companies — where I was working — because HD requires quite a lot more bandwidth than standard def, and bandwidth was/is a scarce resource. I got the timing just about spot on, but was wrong about the technology that would deliver those displays.
We’ve reached another point where it’s difficult to say which technologies are going to be in wide use ten years out. [Techno-babble warning] Photo-reactive quantum-dot LEDs in place of the color filters in LCD screens are out now, if you’re willing to pay for them, and give a better picture. Ditto for OLEDs. Electro-reactive quantum dot LEDs are more than just lab curiosities, and several small companies are working on the scaling-up problems. So-called “pick and place” LEDs are still hideously expensive (for consumer devices), but are capable of insanely good images.Report
Tt7 – also according to official Chinese media, they are growing moon cotton on the farside probe.Report