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Archive for the ‘Transportation’ Category

The fenestron already improved helicopter noise problems a lot (less tail rotor and main rotor interference) but this new blade tip they’re working with at Eurocopter seems like a great advance!

If the power levels / flight situations are the same in the two examples but the difference in the annoyance level of the sound is striking.

Now something similar for airplane propellers!

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I just updated the blog title and again just watched the page and the blurb.

It’s when we start working together that the real healing takes place, … It’s when we start spilling our sweat, and not our blood.

It’s a quote of David Hume, my favorite philosopher. I haven’t read his books though. I was reading a Finnish translation of one but it seemed so tedious with the language that I couldn’t bother. So me favouring him is based on the works of others about him.

The quote reminded me of the conflicts that I’m witnessing. The subject line matter needs to be done. At the moment many parts of climate software seem to be science software – written by people in a hurry with little planning, and code that has seen different people adding bits and pieces here and there, making it a big mess. Fortran and supercomputers and all that. Well, most software is a mess. Twenty man years, said MT. That’s a small amount of money considering how much is at stake and even compared to the amount of huffing and puffing efforts around the subject. I am available.

What else needs healing and sweat spilling? Well, quite many things. Including stuff in my personal life.

There are lots of old (sometimes Fortran) code packages hanging around. Nuclear stuff, rocket trajectory calculations, rocket engine chemical/thermodynamics performance… You name it, anything a young man is interested in seems to depend on these archaic pieces of software. So there’s a lot of potential work here but it seems so big for just a lone person to do much on their own free time.

The blog title picture is just some hinge flapped NACA foils simulated with the vortex lattice method in QFLR5. That actually IS a free software project, mostly by Andre Deperrois and uses Mark Drela’s XFOIL for 2D calcs. In the picture, the front wing has NACA 4415 with 6 m span, 1 m chord, 25% chord 15 degree full span flap, and the tail is a NACA 0012 with 2 m span 0.5 m chord, 40% flap or elevator at -15 degrees. Flying at 5 degrees AoA (plus 4 deg to the front wing) and 18.9 m/s, lifting about 2000 N. Absolutely no guarantees about the results.

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It seems the US is getting onto private aviation bashing. No trailerable aircraft to airports or automobile gasoline for the engines. The former could be seen to be motivated by trying to prevent building bombs into aircraft, the latter is a bit more obscure, probably having to do with ethanol additives that some aircraft engines (or fuel pipes and seals) can’t handle. But it’s peculiar to outright ban auto fuel. The people can deal with this themselves. Probably you could easily produce ethanol kits for most auto fuel engine systems.

I’m reminded of Finnish automobile laws which are probably the strictest in the world. You can’t do this or that and even if you do something out of the ordinary within the very narrow limits, your new vehicle will probably be taxed to death. Even ordinary new or used imported cars have high taxes in Finland and gasoline costs over 1.3 euros per liter. The roads take a lot of effort to build and maintain because the harsh winters cause the ground to freeze, causing bumps in anything but very deeply and thoroughly based roads, the snow has to be plowed and salt is dispensed to melt it, lots of streetlights are used since the winters are dark, frequent repaving is needed because of winter tires grinding the asphalt etc. This money has to be taken from somewhere. That I understand.

But try to bring a used car from say Germany to Finland. It’s a disaster. A friend of mine spent the summer in central Europe and bought a decent smallish German car for 1500 euros. He drove around Europe a few thousand kilometers with it with the temporary registration and everything worked fine. I was on a trip too and joined him in Poland and we drove the car to Finland. It was a well working machine with no problems whatsoever, I’ve driven worse perfectly legal vehicles in Finland. It even had air conditioning which made the trip nice. But when he arrived in Finland, the problems started piling. First lots of customs payments, then he had to bring the car for checkup so it could be registered in Finland. Just that exact model had not been imported to Finland. The inspector demanded some changes to be made at a repair shop (changes that would not affect the car’s function in any way, may I add!), to make the car resemble more its ordinary sibling model. Yet when some were made at a great cost, it was discovered by another inspector the changes were actually wrong. It was made clear that the car could not be registered. My friend contemplated a lawsuit, but here they take so many years and so much money. In the end the perfectly good drivable and safe car ended up to be crushed. All because of stupid overstrict laws and an incompetent inspection system. This is not protecting road safety, it’s protecting local car dealers.

Vehicle changes and registrations are really a complex world here. There’s a group of people working on an “open source hardware” electric conversion of Toyota Corolla, sähköautot.fi. Even the prime minister has promised tax exemptions for electric vehicles but I think at the moment they’re taxed as harshly as diesel vehicles (which is much more than gasoline, but the fuel is cheaper – but for electrics the fuel is cheaper anyway!). Same with a guy who has a home made biogas facility at his cow farm in central Finland. The overregulation is strangling innovation and experimentation. Meanwhile in Sweden they are experimenting with all kinds of alternative fuels and give perks like free parking to less polluting vehicles. The Finnish car factory in Uusikaupunki that used to do Porsche Boxters is now changing over to electric vehicles to be on the leading edge. And none of them will be on sale locally, all for export, because of the tax system and regulations. Someone should wake up!

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Chevy Volt

Jay Leno testing one briefly. It’s a plugin series hybrid, the gasoline engine doesn’t “help” the acceleration like in the parallel hybrid cars produced so far, and it’s supposed to come out in 2010. But a 1.4 liter gasoline engine seems awfully big and probably increases weight of the vehicle – which is a lot, about 1700 kg. The car is so heavy because of the electric stuff though that maybe the large gas engine is necessary as well.

Why does 1.4 liters seem a lot? Well, since it’s a series hybrid, you only need to produce the average power, the batteries handle the bumps. Typically cars  use only a fraction of their available peak power. But in a series hybrid the gas engine can be tuned to being small and running at pretty high constant RPM to make it light and efficient as well. Many ordinary gasoline cars of 1000+ kg mass have 1.4 liter engines over here, hence it looks like a huge displacement for a series hybrid.

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Merry Christmas everyone!

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Photos of a certain large Soviet ground effect vehicle.

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http://vimeo.com/6382632 An old video.

The Burnelli “lifting body with wings” style transport and passenger planes might have been good. Too bad it’s pretty hard to pressurize compared to tube hulls that were just introduced when Burnelli aircraft were proposed.

I think the report has a problem typical of such short “documentaries”. They assert a lot that is not very well based. A very biased view. Where did they get their experts? Did they quote their most salient points?

There are other open questions left there. For example landing at slower speeds would probably mean more drag in cruise (because of large lifting surfaces). I’m not terribly impressed with the video report. If a lot of their other reporting is of similar quality, it’s no wonder that so many people have so weird opinions on a number of things, if they really believe what is said on TV…

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Or what you are going to call it, an unrealized proposal from Aerojet around 1984. PDF Found on NTRS.

The idea was to have two turbopumps (like on SSME), but instead operate on the expander cycle. Two heat exchangers, two turbines, two pumps. One for each propellant.

 

aerojet_cycle

Both propellants go through a heat exchanger and an expander driving a pump

 

This is a LOX-hydrogen engine. Also this means that since there is the same propellant on both sides of the axle, in the turbine and in the pump, no elaborate seals are needed. Original intent for these engines was for in-space reusable stuff, that needs to be operated many times and for a long time without maintenance. Size was in the RL10 class, about 70 kN. (RL10 has grown though.)

aerojet_margin
Simplicity and margin were claimed

Think for example if you let a fired turbopump sit in space for a long time. Will some fuel leak to the oxidizer side through the seals? This could avoid that. (You can use helium purges too though but then you’ve got one more fluids you need to tank.)

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Sandman

Armadillo flying to 600+ meters with a "mod". I say, it looks like the East German Sandman!

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Viking Line’s Mariella passenger and car ferry was drifting without steering capability between 00:30 and 01:00 (24 hour notation) near Utö in the Gulf of Finland on saturday morning 2009-09-19. YLE and HBL have more. There apparently was some spare power on so it was not a total blackout. This made the papers while the previous incident with Eckerö Line Nordlandia made it only to Hufvudstadsbladet (thumbs up to them!).

There was little traffic there then, but that’s just a matter of good luck.

This is dangerous, there are usually about a thousand people on board in these ships, and the Gulf of Finland is a busy traffic area, so vehicles without steering capability could collide easily.

Tallink / Silja Line sail still without such an incident.

Now would be the time to up the official supervision hugely – not after a real accident happens!

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