There has been a number of interesting threads here on the links between YKK and various items from WWII, such as the model names of the robots.
Something at the back of my mind rang a bell when I saw the Misago, the craft Sensei flew over the surface of the sea http://ykk.misago.org/Volume4/65, and the one Alpha laid to rest at sea later.
Now, look closely at the engine. Then take a look here: http://www.aardvark.co.nz/pjet/argusv1.shtml . Note the shape but also the mounting of the engine. There are several videos on this page that show the launch of the much feared V1 from WWII.
- C_P
Saturday, May 8, 2004
Yes it is this engine, but it's not all. The Misago craft is more or less similair to one of the german jet fighters from WW II - Heinkel He-162 "Volksjaeger". You can find info and photos about it anywhere on the net, for example here:
http://www.faqs.org/docs/air/avhe162.html
or here (more photos of the He-162):
http://www.luftwaffepics.com/lhe1621.htm
- Cornel
Saturday, May 8, 2004
The V-1 engine was later used on the Volkjaeger but this isn't the same engine as the one on the Misago. The Argus engine was a pulsejet with a combustion chamber fronted with flap valves. The explosion (the "pulse") in the chamber was ducted out the rear pipe to produce thrust and the partial vacuum sucked fresh air in through the flap valves. Fuel was sprayed in and another explosion pulse fired by a sparkplug arrangement.
In YKK the Misago is described as being built around a car supercharger (in fact something that size would probably have come from a truck and might have been a turbocharger rather than a supercharger as they are designed to withstand high temps unlike superchargers). With the cowling off in 066.jpg you can see multiple combustion chambers which is not a pulsejet design feature. In 069.jpg are the words "The scream of the turbine" -- again not a pulsejet feature.
Mr. Asashino is knowledgeable about aircraft and would not make those kinds of mistakes about a propulsion sysem. The earliest jet engines used a separate air compressor to feed the combustion chambers -- Frank Wittle's genius was to drive the compressor with the jet exhaust in an axial mode. The Misago's engine seems to be a separate-compressor type; it just looks superficially like a pulsejet.
Is that a younger Ayase standing at the control desk in the top frame of 067.jpg?
- Robert Sneddon
Saturday, May 8, 2004
Howdy,
Here is the page mentioned above:
http://ykk.misago.org/Volume4/67
But I don't think it's Ayase. If Ayase is human, then hey should be a little boy in this flashback. If he's a robot, then this research was done before the A7 prototypes were created.
Best,
Dave
- dDave
Sunday, May 9, 2004
It is true that the text describes turbine and supercharger. Neverthless the shape of the jet engine is that of a pulse jet; the wider chamber and a long narrow tube are charactertistic. A turbine engine is far shorter and, as you point out, the sound is very different.
I am puzzled about this discrepancy in shape and description.
- C_P
Monday, May 10, 2004
Remembering that a pulse jet requires an initial thrust (or air movement) to get it running, perhaps the turbine (which, being from a turbocharger, would not be producing that much thrust on it's own) was being used as the starter for the pulsejet.
Another alternative is that most bizarre of Italian inventions - the after-burning ducted fan. Although it must be said that the engine geometry is against that.
-Rob.
- Rob Masters
Monday, May 10, 2004
A pulsejet doesn't require an inital movement to start running, it only needs the first "charge" to go off successfully. The venturi shape of the exhaust tube causes a partial vacuum to be left behind in the combustion chamber. This vacuum opens the flaps in the front, sucking in more air to be mixed with the sprayed fuel before the next ignition.
The reason for the launching ramp system used for the V-1 was that until it is travelling through the air at a good speed the amount of thrust produced is not very great. The faster it goes the better it runs as air is forced into the combustion chamber rather than relying on a weak partial vacuum to suck it in. The Volksjaeger fighter required a long takeoff run to get up to speed and was cranky on landing as the motor's thrust dropped off uncontrollably as its speed dropped. It was, as I understand it, a difficult trick to abort a landing and "go around" because of this.
- Robert Sneddon
Tuesday, May 11, 2004
I always thought that the pulsejests needed an initial airflow, but could sustain a burn after startup - and that this was the major advantage over ramjets. Goes to show, I guess.
In anyevent, the same could still pretty much hold true - but using the output of the turbocharger to keep the airflow up during the lower-speed section of the run, instead of using it as a 'starter-motor'.
Or, OTOH, they might be using it as a cheap turbopump to deliver fuel to the combustion chamber. (Mind you, the fuel demands of a pulse jet don't really require the use of a turbopump!)
- Rob Masters
Saturday, May 15, 2004
Re: pulsejets.
there was a lot of film in the German archives of the development of many of their aircraft and rockets, and there's at least one piece of film I recall seeing which showed a static test of the Argus engine with the flaps rattling open and closed at the front of the engine.
We only ever see the front of the Misago's engine clearly in one of the frontispiece drawings, as I recall -- ah yes, "Sensei's Mark" at the beginning of Ch. 53, Vol. 6, 137.jpg, with a rather sexy-looking young Sensei draped alluringly over the Misago's engine. There's a rectangular box mounted over the intake with what looks like a motor on one side, probably a temporary starter unit as the attached cables aren't going to withstand the 620kph airspeeds the Misago reaches in its virgin run. I'm guessing the box contains the super/turbocharger gearbox which drives the compressor and the motor unit is used to spin it up initially but I could very well be mistaken as the tube connecting it to the Misago's hull seems the most obvious way to drive the 'charger.
What we can see down the intake is circular, indicating a compressor turbine disc rather than the Venetian-blind flap-valve system the Argus used.
Just had an idea -- the long jet tube might be for an afterburner. It's not very fuel-efficient but given the Misago's expected lifespan that would not necessarily have been a real problem.
Right, now I've had a chance to look at what I've written and cross-check it with the manga, there's a view of the front of the Misago's engine in Chapter 28 065.jpg which, of course, looks nothing like the drawing in "Sensei's Mark". Argh.
No box on the front.
Could it be the "Sensei's Mark" hydroplane is a different ship to Misago?
- Robert Sneddon
Sunday, May 16, 2004
Howdy,
The two craft are different. Sensei tells us that the second ship hasn't even sailed once.
http://ykk.misago.org/Volume5/77
Best,
Dave
- dDave
Sunday, May 16, 2004
You know, it's one of the delights of YKK that I can read through it and then forget about bits like "Early Morning" and "Sea Current" so that I can enjoy them for the first time again.
- Robert Sneddon
Monday, May 17, 2004
Sorry to revive such an old topic, but I thought there was something important to add...
From what I can tell, the craft flown by sensei are ekranoplans, as explained here:
http://aquaglide.ru/index_e.htm (click on history)
In short, they use ground effect to create a massive amount of lift off of their tiny wings. The lift created is so great, in fact, that there isn't really any limit to the size of an ekranoplan. For example, the Lun (the one with six missile launch tubes on it) had a maximum take-off weight of 400 tons!
The design is different from those in the pictures because the Misago was made for speed rather than cargo transport. The wings are blended with the tail of the craft in order to protect the engine, as well as to move the control surfaces farther away from the craft's center of gravity. Or at least, thats what I think.
- Michael Duitsman
Monday, May 16, 2005
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