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Clive are we talking about heat conductivity or electrical conductivity?

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Is the 1kV being applied to the device or is it generating it?

 

Andy

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Clive are we talking about heat conductivity or electrical conductivity?

 

Electrical Derek

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Is the 1kV being applied to the device or is it generating it?

 

Andy

 

To the device Andy

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I awake and discover you still haven't got this one! Anything to do with St Elmo's fire?

 

Yes I thought it would all be over on the first night.

 

Not St Elmo's fire as such but on a very very small scale there is a sort similarity.

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Is is possible to increase the temperature of cold air, thereby improving the efficiency of combustion...?

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Or part of some sort of high voltage ignition system for a piston engine:

 

A magneto has one spark generating system and a spark distributor which directs the spark to the appropriate cylinder. This spark distribution system relies on the air in the distributor as an insulator against ground and other plug lead terminals. At altitude the insulation value of air is reduced proportional to the reduction in density (first order). The electrons at the rotor evaluate their environment for the path of least resistance. The plug terminal adjacent to the rotor tip has a higher resistance than other terminals in the distributor because the sparkplug it is connected to is at the end of the compression cycle. From this it is clear that the altitude at which a distributor misfires is lowered if the cylinder pressures are increased, i.e., by higher compression ratios, increased ram pressure, extensive porting and turbo charging. Larger gaps at the plugs and worn electrodes also contribute. On the other end, the tendency to misfire in the distributor is increased if moisture is present, the insulation value of the air is reduced by heat, altitude or ionization (a result of arcing), or the available voltage potential from the spark generating system, be it a magneto or electronic source, is increased.

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Is is possible to increase the temperature of cold air, thereby improving the efficiency of combustion...?

 

That's not something I had not thought about RH. It seems a valid point but it is not related to this device.

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Is it an igniter for use in the case of a flame-out at altitude?

 

That's not the specific issue Terry that this is designed to overcome.

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Or part of some sort of high voltage ignition system for a piston engine:

 

A magneto has one spark generating system and a spark distributor which directs the spark to the appropriate cylinder. This spark distribution system relies on the air in the distributor as an insulator against ground and other plug lead terminals. At altitude the insulation value of air is reduced proportional to the reduction in density (first order). The electrons at the rotor evaluate their environment for the path of least resistance. The plug terminal adjacent to the rotor tip has a higher resistance than other terminals in the distributor because the sparkplug it is connected to is at the end of the compression cycle. From this it is clear that the altitude at which a distributor misfires is lowered if the cylinder pressures are increased, i.e., by higher compression ratios, increased ram pressure, extensive porting and turbo charging. Larger gaps at the plugs and worn electrodes also contribute. On the other end, the tendency to misfire in the distributor is increased if moisture is present, the insulation value of the air is reduced by heat, altitude or ionization (a result of arcing), or the available voltage potential from the spark generating system, be it a magneto or electronic source, is increased.

 

Well hunted down Terry http://www.lightspeedengineering.com/Technicalities/sport_aviation95.html

 

But this is not a high voltage system, but you are right it is ignition related but Degsy got there first.

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Is it creating a spark?

 

Yes well done Derek this is indeed a sparking plug!

 

The point is that it is a low voltage system. The problem being that at high altitudes the air density is decreased which causes problems in 10kV systems with the spark jumping the insuation in the plug itself or in the HT leads, especially after long operating periods.

 

In this plug the spark doesn't jump an air gap but "glides" along the surface of the insulation ceramic. This can be achieved with voltages as low as 400-1000 volts.

 

The source of this is the Combined Intelligence Objectives Sub-Committee File No. XXIX-53 15th August 1945.

 

Diagram to follow.

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AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAARRRRRRRRRRRRGGGGGGHHHHH!!!! :mad:

 

Alec

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Yes Alec it was amazing to see some of the complex thought processes going on but missing the ignition issue.

 

These tests were as the result of the activities at the Junkers plant in Dessau in conjunction with Siemens and Beru. The plug below was the Beru solution to the problem. This design also reduced the liability to oil-up after long periods of idling or aerobatics.

 

Tests over 26 hours with varying loads showed the plugs to be trouble free. Seems curious that this system did not catch on?

 

Scan0003a.jpg

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The only thing I've seen close are the Wankel spark plugs, although they are more to do with the lack of protrusion, there are distinct similarities.

 

Alec.

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Thanks Clive for a really interesting conundrum with really interesting science that lasted wayyyy longer than usual... Cheers Robert

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Yes well done Derek this is indeed a sparking plug!

 

The point is that it is a low voltage system. The problem being that at high altitudes the air density is decreased which causes problems in 10kV systems with the spark jumping the insuation in the plug itself or in the HT leads, especially after long operating periods.

 

In this plug the spark doesn't jump an air gap but "glides" along the surface of the insulation ceramic. This can be achieved with voltages as low as 400-1000 volts.

 

The source of this is the Combined Intelligence Objectives Sub-Committee File No. XXIX-53 15th August 1945.

 

Diagram to follow.

 

.

Thanks Clive. I was late in seeing this post by which time the answers were way over my head:???. The clues were there, I just couldn't see the wood for the trees.

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Yes I was fascinated when I came across these investigations & having been sitting on it until I had a reliable internet connection.

 

Equally fascinating is File No. XXIX-54 that investigated an alternative solution to the HT problem, not just reducing it but dispensing with HT altogether by means of "ignition oil".

 

Although the idea worked it failed due to problems with temperature especially cold starting.

 

Scan0005.jpg

 

Scan0006.jpg

 

Scan0007.jpg

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