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Archive for the ‘airplane’ Category

Modern manufacturing technologies enable strange shapes and could produce unconventional pumps. What is good for small scale rockets if turbines and centrifugal pumps have too much tip losses?

Rotary engines have vastly better power to weight ratios and vibrate less than piston engines. They’re also expensive and hard to build (cue modern manufacturing again). Here is one demonstrated in a paramotor, Parajet Cyclone using a Rotron engine. Love the music.

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This is becoming an aerospace video blog. 🙂

The eighties

Versus the teens

Westland Lynx only reached 90 m/s while X2 is doing 130 m/s. The ability to let the rotor spin slowly since only the advancing blade needs to lift in a counter rotating rotor allows the X2 reach a high speed.

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Most people with interest in aerospace history know of Barnes Wallis’ geodetic structures, most famously used on the Vickers Wellington. He first invented them for the R100 airship, basically a weave of thin aluminum shapes going in different directions, forming a grid. No bulkheads or even wing spars needed, but it was quite complicated to build. Fabric was used as a cover, first linen and later thin steel wire mesh. It became outdated when airplanes were pressurized and moved to aluminium monocoque structures.

Vickers Wellington with some skin shot off

Well, now, airplane manufacturing technologies are changing again, after some 70 years of riveted aluminium sheets, bulkheads and spars. Composites laid by robots enable fancy shapes, and optimizing the strenght carefully in various directions. Boeing has been looking at a 737 replacement. So far, pressure hulls have had to be cylinder or ball sections – only that way the thin skin can be in pure tension, the only force it can really resist. Often a double bubble has been used, with the cabin floor dividing the lower and upper half into two circular sections and also keeping the left and right side together at the same time. A circular frame is not very space efficient for humans though, so Sankrithi et al at Boeing figured out how to put fibers in a grid to enable a roughly elliptical shape that is wider than it is tall. The advantages are not entirely clear to me from their description, since they seem to say the ratio of seats per circumference is similar to a circular frame, but it is nevertheless interesting. (Also, it’s strange that Free patents online shows that the patent was filed in 2009, yet Google shows it was filed in 2005, yet they seem the same at first glance).

Fiber reinforcement grid geometries for an airplane fuselage

This has some relation to the X-33 where they also attempted non-cylindrical composite pressure vessels. The technology has advanced since though.

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In a patent by the famous Barnaby Wainfan. EDIT: corrected the link. This patent was filed in 2006 and granted in 2008.

Enter, turn, boost, glide

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If you speak german, this video is nice. They show it driving, in construction and design.

Though it is complex, heavy at 450 kg and expensive at 62,000 euros. Uses a BMW motorcycle engine and sits two people in tandem and looks like an airplane cockpit. It could serve as an interesting datapoint if more fuel efficient non-mass transport vehicles are to be developed for single commuters. The E-tracer version has had success in the automotive X-Prize. It’s no small deal, since that includes handling tests.

Overview of the Monotracer in english:

Lane change handling test at automotive X-Prize:

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Too much to fit into one update. The leads could be

Communisms’ legacy

  • in the Baltic states
  • in East Berlin
  • in demographies
  • its relation to other genocides like the holocaust
  • a prison
  • how do the people live today
  • Ignalina and its replacement
  • (Peripherally a subject matter, the western powers’ somewhat interesting views on Finnish-Soviet wars and relations and their potential wagings of war against the reds – project Pike forum summary and the book here)

Russian forest fires

  • Beriev’s share price (A Be-200 appears on the video 15 seconds in, hat tip to Secret Projects)
  • organization of society and its ability to handle crises
  • the smoke in Helsinki because of that
  • should they care

Hot weather

  • Here, after the coldest ever winter comes the hottest ever summer
  • Is it largely just winds from the southeast’s continental hotness – when usually they blow from the more marine southwest?

Climategate blahblah

  • BBC has apologized and some NYT reporter has said the NYT should apologize on some small back page article.
  • Follow Michael Tobis for climate related news

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I didn’t have a camera with me but I was surprised at their impressiveness. From afar, they looked like old gas storage vessels (like in Suvilahti, Helsinki), but they really were dome-shaped seaplane hangars. Luckily Flickr has at least some photo as well as Panoramio here. The museum has home pages here.

I picked the wrong day to go there as it seems all of Tallinn’s museums are closed on mondays and tuesdays (The Kumu art museum was one potential destination too), but I couldn’t really choose the day anyway at that point. I could still tour the stuff that was outside. There was a lot of construction and renovation work going on. The domes were full of scaffolding for builders. Actually that would have provided for a really good photo opportunity since it divided the volume into cubes as a great visualization of the size of the thing, together with people for scale. The top was being sandblasted and you could see the rebar from many places. This is not a cheap project and will be ready by 2011.

They are not super-huge though. No Saro Princess could fit in them. They were built in 1916 and 1917 after all! I could also see the old first independence battle’s ice breaker Suur Tõll and the Lembit submarine, as well as an array of patrol boats donated by various countries to the young Estonian defence force in the nineties.

I will write other things inspired by the trip in other posts, there was certainly a large amount of thoughts that arose and observations that were made.

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