"Grindintosecond" (Grindintosecond)
09/03/2014 at 00:09 • Filed to: planelopnik
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"Grindintosecond" (Grindintosecond)
09/03/2014 at 00:09 • Filed to: planelopnik | 6
| 6 |
...was from Germany during WW2. Why? Well, Somehow Junkers thought two crankshafts driving gears to one prop output was a good idea. It worked. 800hp from a 1,300 lb. engine is nearly the same power per pound we see in today's certified piston aero engines, but theirs were diesel and more efficient.
They supercharged it and if you look close, the pistons aren't exactly arriving in the middle at the same time. This was the piston port intake and exhaust at play and it greatly enhanced efficiency and cut the nasty smoky style of this method of breathing. One piston at one end uncovers the exhaust port for a bit before the intake port at the other end is uncovered and blows in the air charge. This was, in effect, an opposed-piston valveless, supercharged uniflow scavenged, two-stroke Diesel. That's quite a bit to say when you slide up to that woman at the bar and make her fall for you run away.
This two-stroke diesel with twelve pistons sharing 6 cylinders was tested in various uses. Fighters adjusted power frequently and at max power it was found somewhat fragile. The use of this engine was in a vertical location with an upper and lower crankshaft. 3/4 of the power was from the upper crankshaft, the lower used mostly to driveup accessories and pumps like fuel systems and compressors. In the end, although super efficient, it was only suitable for use in airships and long range or high-altitude patrol craft, like the BV-138
After the war, Napier of England built their own version. After testing, the design was tripled into a triangle shape and was installed in fast attack naval ships, where the engine itself was half the size of equally powerful engines but also one FIFTH the weight. Trains were next in the late 50's and 60's. They became the most compact and powerful diesel engine in the world, the Napier Deltic. Again, fantastic information to swoon the ladies with talk to nerddudes with at the next keg party.
Presently there have been some strides in Aero-diesel engine work but that was cut dramatically by recent wars, as the manufacturers were very capable but also very needy of income generating contracts for the defense departments. This makes only a few people left working on Diesels for aircraft and only one certified manufacturer, Theilert-Centurion, who is now part of the Continental engine group, which are heavily based on Mercedes-Benz engines, as well as the French SMA engine which is also license built by Continental motors.
Other future developments has Lycoming supplying the General Atomics MQ-1c grey eagle drone with the DEL-120 diesel and they are very quiet and uncommunicative on the project. Decent way to work out bugs before a civil program. Regardless, these are the only options at the moment to put an oil burner in the air without going with a very pricey and thirsty turbine.
So I wouldn't call the new stuff more successful just yet, it has it's teething trouble and it has yet to sell 900 examples like the Junkers Jum0 diesel series has; but you could count the DA-42 twin, that has sold over a thousand examples, and all of their 1.7 engines have terrible terrible service history. The new stuff is coming.
GhostZ
> Grindintosecond
09/03/2014 at 00:18 |
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How come diesel never took off for planes?
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Grindintosecond
> GhostZ
09/03/2014 at 00:22 |
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A combination of engine tech and markets. Why mess with gas. It's cheap, plentiful and easy to work with. Only now is it something to think about becuase AV gas is leaded and the efforts to clean it up are driving the diesel engineering. Motor gas can be used in planes but it has to be in lower compression engines. because of the different vapor properties of leaded vs. regular gas.
norskracer98-ExploringTheOutback
> GhostZ
09/03/2014 at 00:22 |
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Because plans don't fly, planes do.
Cé hé sin
> Grindintosecond
09/03/2014 at 04:45 |
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Oh, some love for the Napier Deltic! One of the weirdest engines out there.
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Grindintosecond
> Cé hé sin
09/03/2014 at 09:32 |
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Oh yeah. It's amazing how one invention can lead to something very unique. So weird yet absolutely wonderful.
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Cé hé sin
> Grindintosecond
09/03/2014 at 14:57 |
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Indeed. The Deltic, as well as being an example of the spawn of Satan was a diesel so starting one from cold was not the work of a moment.
As we see and hear here