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The Martin Fleischmann Memorial Project is a group dedicated to researching Low Energy Nuclear Reactions (often referred to as LENR) while sharing all procedures, data, and results openly online. We rely on comments from online contributors to aid us in developing our experiments and contemplating the results. We invite everyone to participate in our discussions, which take place in the comments of our experiment posts. These links can be seen along the right-hand side of this page. Please browse around and give us your feedback. We look forward to seeing you around Quantum Heat.

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TOPIC: Outside Glass Heating Time Constant

#205 7 years 3 months ago
Outside Glass Heating Time Constant

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Hello guys. Your reheating process had a tiny silver lining attached to it. I performed some analysis of the exponential rise time occurring while the 48 watts was being applied to the heating wire and obtained a reasonable estimate of the net system time constant. This information can be used as you analyze various drive waveforms while monitoring the outside glass heating response.

I was a bit surprised to see such a good fit between the actual glass temperature and my simple model. The direct IR path did not appear to have a dominate role in this situation. It is not evident why this is the case, but the numbers seem pretty valid.

The time constant I determined is 406.5 seconds, which is about 6.78 minutes. Perhaps it would be interesting to perform the same calculation when power is only applied to the LENR active wire, but this has not been done thus far. I am assuming that both would be comparable.

I used the data from your server that began at the following time: 11/14/2012 17:44.

If anyone would like to have further details as to how to apply this time constant to the temperature readings, just enter a request and I will explain my calculations.
Last Edit: 7 years 3 months ago by Dave.
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#220 7 years 3 months ago
Outside Glass Heating Time Constant

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Hello again. I decided to see if there was a large difference in the time constant associated with heating of the Mica versus that of the Glass Outer. I assumed that the mica would heat quicker since it is in contact with the heating wire and that seems to be the situation.

The mica heating follows an exponential curve with a time constant of 334.13 seconds which is a modest amount faster than the outer glass, but not as much as I was expecting. This corresponds to a time of 5.57 minutes.

I used the same time period as for the outer glass calculation for my data source. The chosen period is during the heating up phase.

This result leads me to believe that the main transfer of heat is by gas conduction and I do not see clear evidence of IR transfer in this test. It would be interesting to perform an experiment that would show the IR effect in an enhanced way to determine its characteristics.

I have thoughts of driving the heating wire with a variable duty cycle. If you could periodically apply power for 30 seconds and then remove it quickly for 30 seconds, the response of the outer glass would be a nice saw tooth waveform that we could calculate easily. Changes in shape might indicate the magnitude of the faster acting IR behavior.

I suspect that a duty cycle waveform of this nature might allow you to achieve an interesting wire heating profile. Another plus would be the ability to measure wire resistance during the non driven period and to monitor its behavior as the wire cools.

Keep up the good work.
Last Edit: 7 years 3 months ago by Dave.
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#234 7 years 3 months ago
Outside Glass Heating Time Constant

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I just completed the same operation on the T_Well data and found that it has a time constant almost identical to that of the mica.

I calculate a value of 330.0 seconds for this curve. This corresponds to a filter with a cut off of .482
millihertz . Any heating pulse applied to the inactive wire will be filtered as if a one pole filter were applied to it with the above cut off frequency. The curve fit is fairly accurate with an error of less than 1 degrees C over a large temperature range.

With the information supplied, you can simulate the temperature waveform at any of these three points when the power wire is subjected to various drive waveforms.
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