Posts by Daniel_G

    @Ascoli, nichrome wire resistance varies greatly with temperature. There is not any logical reason to expect control and active heaters to have the same resistance nor is it necessary for calibration to use the exact same heater. Resistance heaters convert electrical power to heat and the electrical power is measured easily. Calibration of a colorimeter do not require identical conditions or heaters to work properly.

    @SOT has reiterated my argument exactly. We both agree the postulated argument goes the wrong way but @THH is saying that if there is an adjustment based on the PSU inefficiency that then that could show up as excess power. I think Jed has cleared the this issue already as the power in is measured between the PSU AND also checked at the source as a “reality check” so no possible source for error here. QED.

    @THH, I have a question for you from a theme that seems to be popping up now and again after reading your posts. At multiple times you mentioned possible discrepancy about input power measurement of Mizuno not clear if its measured before or after the PSU. Yes, I agree it would be nice if input was measured after the PSU but 100% of all PSU's have a finite efficiency so even if it was measured at the line voltage outlet level, that would over-estimate (not under-estimate) the input power unless you think the PSU efficiency is over 100%. So, yes I agree that these things should be cleared up but in terms of any possible error that would under-estimate input power, this one is a non-starter. Can we agree upon that in principle? As Jed says, there is nothing easier to measure than input power.


    In terms of the flow velocity profile, if Paradigmnoia is having problems with mixing, I suggest stuffing a high-porosity sponge filter like what you can buy at K&N, etc. that will remove any vortices, etc. from the fan before the air enters the tube. These would have minimal pressure loss and should solve most of these profile issues being discussed.

    Just a little confirmation of physics and pardon me if I missed something here but the specific heat of air calculation you are using assumes dry air which I am positive is not the case. It would improve accuracy of the airflow calorimeter if RH was measured on the inlet and outlet, to get a better specific heat calculation. Has this been done? Even if both temp and RH were measured at one point together, one could calculate the actual specific heat with a psychrometric chart.

    I don't think the 0.3MPa is the reactor pressure. They say they inject 0.0002 moles of D2. If you assume a 3L vessel volume, that gives about 168Pa of pressure which is in the correct zone. The 0.3MPa seems to be a mistranslation.


    Anyway, the 0.0002 moles of D2 gives 57.2J of heat if burned (heat of combustion) so the 47,000J output from this experiment is 783 x the total chemical energy of the D2 injected into the device.

    That's good to know. Thanks. I think that's what the instrument company told Mizuno, which is why he selected the hot wire one.


    As I said, they recently ran a comparison with a vane type. The vane one results were a little higher. It is a little hard to compare them, but I think I am doing it right. It was maybe 16% higher, worst case. That would increase the excess heat. That can't be right, because a 16% increase would make some of the low-power calibrations show excess heat, which is impossible. They may have done some more tests with the new anemometer. I assume they did, but I don't have any additional data from it. I expect if they spent a week or two wringing it out, they could find out why it was a little higher, fix the problem, and reconcile the numbers. Maybe not. Maybe they would have to redesign the orifice? I wouldn't know. Of course you would have to re-calibrate and redo everything from the get-go if you did that.


    Even if the two anemometers do not agree completely, I am encouraged. There would have to be gigantic error to "explain away" these results. They would have to be wrong by factor of 6. A 16% error cannot begin to explain that.

    Jed, the 16% error is most likely due to the reduced area that the air has to flow around the center of the anemometer cowling. Since the air flow now has to flow through the annulus space between the cowling and outside piping, the air velocity can be slightly increased when measuring flow from small orifices like Mizuno's calorimeter effluent pipe. This is irrelevant when measuring larger HVAC diffusors/AHUs where these instruments are normally used. But when measuring flow from a small pipe, the path the air flow has to take can increase apparent velocity.

    Cydonia, the evidence is exactly the opposite of what you say. Where do you get such data? As countries develop and become richer they have fewer children. Poverty correlates with a much higher birthrate.

    Irregardless of what the current theories say, the data is quite clear. Lower pressure, more excess heat. Period. It is going to take a lot of time and money to understand the "why" but we clearly understand that "what" now.

    No, that is out of question. The reasons are given in the papers, and I addressed that question specifically in the presentation. Reasons:

    1. The bottom of the calorimeter is well insulated.
    2. A wide variety of reactors have been calibrated in the calorimeter, ranging from 50 kg down to 300 g. They all produced the same Delta T temperature in the air flow. You cannot tell them apart.

    Jed, this is very good science but you are including experience and issues that are not written in the paper. If it was my paper, I would make the argument about the calorimeter and DeltaT, etc. at various known input powers and run the statistics. My comment is not that the science that Mizuno is doing is not correct, its that the paper should be written to incorporate your experience and data so that the paper becomes more rock solid.

    Jed


    Why can’t you run calibrations with the resistance wire on joule heating at 50-300W levels, say every 50W or at the very least run one with an empty reactor but with 300W joule heating? That would remove a lot of doubt by having an accurate calibration at a level that the calorimeter is supposed to be measuring. Just a good practice to have calibration points outside the point of measurement.


    Daniel

    Yes I see my math was wrong and you are correct in the first point. Please accept my apology.


    As for the flow development I agree the difference from Umax to V is going to be less than 10%. If I had time to run this on FLUENT, I could give you an exact number but if you study the charts available, the development of the flow profile in 5xD is going to be very low and that's why I agree with the <10% figure. Perhaps if I have time next week I can run the simulation but the air coming out of the fan is going to be very turbulent and the measurement point at 5xD is not going to allow the flow to develop at all. I think based on this we can agree that the COP figure given in this experiment is still far beyond any possible error in the flow measurement. Right?


    Output heat was stabilized at 303W @ input of 50W so if we assume the worst case scenario, and multiply the 303W measured output by 0.815 we get 247W so the lower bound for the COP reading would be 247/50=4.94, still far and above anything that could be explained chemically, especially if this reaction continued for days as Mizuno is showing.


    Just for fun, if we assume that the flow is both laminar and fully developed, Avg. flow is going to be ½ of Umax and then the measured 303W (ignoring calibration) would become 150W, which still gives a COP of 3 which is still very good by LENR standards so I guess I don't really understand why we are spending so much time on this issue. The measured COP is so high, the result is still robust in light of all the possible errors is it not? Or am I missing some part of your argument?


    Oh and the empirically measured data all the way up to 3mm from the outside wall seems to follow the undeveloped flow theory so can we agree that this was a good exercise, but any such flow error would only reduce the COP from the reported 6 all the way down to 3, all other things being equal and although this is nowhere near being valid from the empirical data, even giving you the maximum benefit of the doubt, the COP is still far above anything that could be accounted for through such errors.

    @THHuxlynew, your calculations seem to be erroneous. Here is a copy of my fluid dynamics textbook:


    For Equation 36, you use f-(100Re)^(-⅛) and that gives the ratio of Umax to V of 1.24 but if you use the correct equation that reduces to only 4%. Also note one more important point. The pipe diameter is 6cm and length estimated to be about 30cm so about 5xD only so the flow is nowhere near being fully developed. Even the 4% figure which gives for something like 60xD or at least starts to get close there will be much, much less for a distance only 5xD from the entrance.


    In conclusion, the flow error due to Umax:V ratio is <<4% and probably <2%. To this you only need to add the uncertainty of velocity measurement from the actual anemometer used.


    QED

    1) the Shanetsu insulation used in this paper is rather poor relative to the state of the art insulation (Vacuum insulated panels). This product (https://www.turvac.eu/0/Products/WhatisVIP.aspx) gives extremely low thermal conductivity (3~10x the product Mizuno used) (3,5mW/mK), with just 20 mm thickness, U value less than 0,22 W/(m2K) can be reached. This would allow more precise calibrations at higher temperatures and more capture of the reactor heat in the air flow.


    2) for replicators with sufficient funding a mass flow meter such as this (https://www.sierrainstruments.com/products/oem-probes.html) would help put to bed about 70% of the discussions here. This device provides 1% accuracy in air mass flow and 0.2% in repeatability. This slight modification would leave zero doubt about velocity profiles and turbulent flow, etc. since it measures mass flow not velocity. Also the turndown rate is 1000:1 and dynamic range is 0 to 20,000 SFPM so this device should allow replicators to measure a higher power level at higher temperatures accurately all the way up to 3000W.


    If someone is successful replicating exactly as in the paper, if it were me, I would improve the air mass flow measurements and improve insulation with VIP technology and run the experiment again.

    When you google cold fusion investment right now google returns Woodford Fund goes bankrupt due to Rossi investment and the nature paper that fails to show any anomalous heat. First of all no real investment fund makes a single bet that will bankrupt the firm. Secondly thousands of valid peer reviewed papers are simply ignored. It’s a war out there right now. They are scared. Mizuno’s replications will be the key for this technology to make it out of the development stage and into the commercial stage.

    • Personally I most distrust the airflow measurements. Getting this wrong by 50% would explain these results. We do not actually know where the air speed was tested. Lack of data here means we cannot check this.
    • I think the middle of tube air speed, air temperature, can easily be determined. Airflow is more difficult because flow velocity profile will be non-uniform, reducing to zero at edges of a pipe and higher in the middle. Mizumo talks I think of checking airflow at different points around the reactor. that does not help, and also does not answer the velocity profile question. This could make the +50% apparent results, if ignored.
    • The other uncertainties seem well bounded by me and although we would need careful and detailed results I feel these are less problematic

    For about $20 I can buy a mass flow sensor from any modern car with a pulse or voltage output with a total uncertainty of around 1.5% (hot wire/hot film-type). Also, RTD measures a difference in mOhms in order to resolve temperatures, normally I use NTC thermistors coupled to an Agilent 34970A and we can get total uncertainty of temperature measurements to about 13mK when using triple point and gallium cell calibrated thermistors.

    Robert, just like an amplifier circuit, high gains give tendency for more instability than low gain circuits so I agree with what THH wrote.

    Accuracy isn't free. But again since its a mass flow meter not a anemometer that measures velocity, there is no issue about laminar vs. turbulent flow profiles, etc. Another idea is if people all buy the $20 car engine mass flow meters and multiple replicators could share the cost of the Sierra device to calibrate their $20 flow meters.

    You are welcome to look at the specifications of the manufacturer. Power cannot, by definition, be measured as voltage or current, alone as it is the product of both. I used to run an engineering company that is a global leader in caloric measurement and metrology. I have no interest in any instrument company. The $20 device, if you followed the discussion, was objected to about its calibration issues in different sized pipes than what it was designed for so I suggested the Sierra solution.

    Although I am new to this field I have been a long time anti-psuedoscience and and anti-pseudoskeptic proponent. Real science always accepts skepticism. Not only accepts but actually good skepticism actually causes real science to thrive and go forward. Just my observation that I see SOT's comments fair and balanced. Those on all sides of this debate would do well, for everyone's benefit, to treat skepticism with professionalism and not resort to sarcasm which is just a passive aggressive technique to belittle the skeptic. Address the scientific issues with professionalism. Resorting to sarcasm actually only belittles the person being sarcastic. Just my two cents...