Rossi Lugano/early demo's revisited. (technical)

  • LDM ,

    If we, for sake of discussion, suppose that the recursive method did exaggerate the dummy reported rib area temperature, and so reduce it to the temperature it might have been without the exaggeration, might then re-calculated output and reported input become much closer together? I propose about 380 C, rather than about 450 C, simply by looking at table 2, and comparing to the value demonstrated there when using an emissivity of 1.0 . (The temperatures of the other parts can be left the same for now).


    As I already stated when I presented the results, this is indeed something I planned on doing.

    However such a recalculation does not make sense if we don't have a good explanation for the large increase in convective energy of the finned area.

    I need to know if there is an error in that calculation or not.

    What I already see is that there is a large difference between my convective heat transfer coefficient and that in the report.

    So I have to investigate this first before doing that next step.

    But I have to go slowly since my concussion is playing up.

  • - What mass should I use for the metal and other solid parts in the Ecat? Heat capacity?


    Oh, we don't need to know these data. For the moment we are only interested in computing the trend of the sum (Emet+Evap) by subtracting from Ein (already known) the sum of Eout (known as well) plus Ewat (1 L at Tout with the usual cp) plus Edisp (please, follows the hints I already gave to you).


    Quote

    - In general, how should temperature for those parts be expected to behave compared to the water?


    We have very few experimental data. For the Ecat device, we have only the temperature of the outlet water Tout, measured by a probe inserted on the vertical arm. So, we are obliged to make very rough approximations, assuming that all the water inside the Ecat is at the temperature measured by the above probe, and referring all the other temperatures to this only value.


    For the metal, we can think that the horizontal pipe - heated by the external band resistors - is hotter than Tout, and that the vertical pipe is at about Tout, apart during the rapid cool down after the starting of flooding. Anyway to perform the required calculations we don't need to know the specific temperature of the metals or other solid parts. We can use Tout to roughly estimate both Ewat and Edisp. In this last case, we know that the heat going to the ambient depends on the temperature of the external surface of the device, and that this temperature is far from being uniform. Anyway we can assume, in very first approximation, that this outer temperature is proportional to Tout so that the heat transfer coefficient I suggested before (1 W/°C) is referred to this value, more specifically to the difference Tout-Tamb.


    Ask me again if needed.

  • Is this correct? Is this what you're looking for?


    Yes. Very good and quick work. Thanks.


    However, I suggest you to update this first set of graphs with the following modification:


    - The title of the upper graph should be "Power (W)" and all the quantity labels should be modified from Ex to Px.


    - You probably computed the thin violet curve (Pmet+Pvap) by differentiating the corresponding (Emet+Evap) curve of the second graph, obtaining in this way wide and disturbing oscillations. I would suggest you to first smoothing the energy curve, and then differentiate it.


    I'll tell you later how to split Emet and Evap on the basis of the updated curves.

  • It isn't the final graph, so I haven't gone into putting the finishing touches yet.


    But more than this, personally I don't find reasonable that the mass of the metals and other solid parts (Emet) reach equilibrium in almost half as much time as the water, given the initial assumption of large thermal inertia.


  • But more than this, personally I don't find reasonable that the mass of the metals and other solid parts (Emet) reach equilibrium in almost half as much time as the water, given the initial assumption of large thermal inertia.


    I didn't say that the thermal inertia was large, I only said that it should be taken into account in evaluating the timing. It's not so strange that the metal reaches its equilibrium faster than water, because most of the electric heaters (4 on a total of 5) were band heaters placed at the external of the pipe.


    As for the calculation of (Pmet+Pvap), a much more simple way to compute it is just doing the same as for energy, that is (Pmet+Pvap) = Pin-(Pout+Pwat+Pdisp).


    Eta:

    Even using the above formula to obtain (Pmet+Pvap), you need to compute Pwat by differentiating the numerical series Ewat. So, you will get the same wide oscillations as before. To avoid them, you should use in any case a much more smoothed numerical series of Ewat.


    If there is any problem, the best thing to do is avoid to draw the Pwat and (Pmet+Pvap) curves in the Power graph. They are not necessary for estimating Evap.

  • Ascoli65

    Speaking of Tout, why would it be changing like that during the initial part of the experiment? This could be showing an important behavior characteristic of the system, it's not good to remove it by using artificially smoothed out data.



    It's even more spiky in the original photo, which means I haven't done a sufficiently good job at digitizing the data in my initial attempt:



  • The spiky look suggests the system is producing regular small bursts of XS heat - that would be typical of some types of LENR.


    There are very many ways in which waveforms look "spiky" which are not LENR.


    For example: the input power waveform is spiky (very obviously so). Is this LENR? No, it is some no doubt identifiable, but unidentified for us, mechanism.


    For this system, that has heated water in tubes, there are all sorts of nonlinear mechanisms to do with bubbles forming and breaking away that lead to apparent output temperature spikes.


    For other system, there will be other mechanisms. Spikes are indicative of some low-level unstable nonlinearity in the system and you can get them from almost anything.


    Beware of apophenia when looking at real-world experimental results. It is easy to see patterns in data that are not there, or due to some unexpected and unidentified low level mechanism.

  • Speaking of Tout, why would it be changing like that during the initial part of the experiment? This could be showing an important behavior characteristic of the system, it's not good to remove it by using artificially smoothed out data.


    That's the normal behavior due to the turbulence in a water flux, when the tip of T probe is wetted by eddies at different temperatures that flows through it. You can see that the oscillation are small until t=11s because the water temperature is still quite uniform. Then, up to t=15s, the rising trend stretches the oscillations making them less visible, but they become more evident as the mean temperature approaches the equilibrium value. After the stopping of the flow, they almost disappear because of the stillness of the water.


    So, don't worry, those oscillations don't show any special characteristic of the system. These are typical fantasies of the LENR world.


    So, it is my opinion that a properly smoothed Tout curve better represents the average temperature of the water, and its derivative provides a good and intelligible trend of Pwat, the heat exchanged between the metal and the water.


    In any case, as already said, this is not essential. Don't waste time in doing that. The graph with the curves of the cumulative energies, that you already provided, already allows a reasonable esteem of Evap. I'm just waiting its final version to suggest you how to do.

  • That's the normal behavior due to the turbulence in a water flux [...]


    Have you tried checking out in practice exactly how much is a ~3.73 g/s water flux?


    The Ecat system tested in December 2010 was presumably filled with water and used standard-sized water piping. I think water would be coming out at very low speed from it.

  • Have you tried checking out in practice exactly how much is a ~3.73 g/s water flux?


    The Ecat system tested in December 2010 was presumably filled with water and used standard-sized water piping. I think water would be coming out at very low speed from it.


    The water speed at the probe location depends on the local cross section and on how the tip of the probe was inserted inside the pipe. Furthermore, as reminded by THH, in that configuration we can expect the early formation of vapor bubbles, which rises much faster in the vertical pipe, inducing an additional turbulence.


    But tell me, please. Do you really think that those oscillations measured by a probe placed half a meter downstream of the alleged "nuclear core" are indicative of "an important behavior characteristic of the system"? Do you think that a temporarily increase of Tout means that all the water inside the device is becoming hotter at the same extent and at the same time? How would you explain what happens in the periods during which the Tout decreases?


    Anyway, as I told you, the smoothing of the Tout curve is not necessary for going forward with the estimation of Evap. You can keep the present curve of Tout, if you like, but be conscious of its real meaning.

  • [...] Do you think that a temporarily increase of Tout means that all the water inside the device is becoming hotter at the same extent and at the same time? How would you explain what happens in the periods during which the Tout decreases?


    A more believable and much simpler non-LENR explanation to me would be that heating power to the water wasn't well monitored and that the system wasn't that well insulated either.


    You can in part also see this in the previously posted Pin / Tout graph: it looks as if the temperature spikes are located close to the power spikes, or at least they have a similar periodicity.


    I'm not sure what the Watts Up Pro ES meter can reliably measure, but it seems to me from the graph provided in the report that it didn't capture correctly all those power spikes.


    Furthermore, since from Krivit's interview Levi didn't appear to be entirely sure in retrospect (or perhaps Krivit's questioning got him confused) that input power to the Ecat got truly removed during the period where some power (10-15W) to the control box still remained, one could argue that power to the heating resistors never really got entirely removed.


    If all of this is truly the case, then it means that the Ecat didn't really work during that test.


    It would also throw a big brick at your reasoning, which from this long discussion it's apparent that it doesn't accept significant changes from the initially forced assumptions/variables (not a good sign).

  • can ,

    I simply wondered (to myself, and was reminded by your comment) if the timestamps were adusted, that the bumps and dips might get more synchronized-looking. I don't really have any theory for why that might be, or if how the data was collected it was possible to get the data feeds out of sync.

    60 Hz clock running on 50 Hz on a measurement device?

    (If it were possible to send different rate timestamps from different measurement equipment, to be consolidated on one display, all sorts of strange things might seem to be happening.)

  • Paradigmnoia

    Levi did mention at some point during Krivit's interview (here from 00:42) that he didn't show all the data together in a single plot because it was sampled at different "clocks" from separate acquisition systems and that putting it all together (similarly to what I did) would have resulted in "artificial" data. Having, in a way, seen this in practice recently I think it has to do more with synchronization and sampling rate than differences in 50/60 Hz clock of the measurement device. For the calculations I had to interpolate and aggregate the different datasets to consistent timestamps, which I guess generates what could be considered artificial data.


    I had to align the data, but didn't find or notice whether the timestamps have been compressed. From the photos it appears that the data shown comes from the logging software that comes with the devices used.

  • It would also throw a big brick at your reasoning, which from this long discussion it's apparent that it doesn't accept significant changes from the initially forced assumptions/variables (not a good sign).


    Sorry, I don't understand which forced assumptions/variables are you talking about. I provided you my interpretation of the curves on the screenshot of the December 2010 test. You correctly raised the issue of what happened to the water during the boiling period (1). I'm just trying to answer your question about how much water remains inside the Ecat.


    I asked you to help me, because of your skill in dealing with numerical series and drawing nice and clean graphs. We are almost at the end of this effort. I am just waiting the final touch on the graphs you posted yesterday (2). If you don't want to use a smoothed curve for Tout, that's OK. Just remove, please, the violet curve from the first graph, modify the title, and substitute Ex with Px where necessary.


    After I have answered your previous question on the basis of my interpretation of what happened during Test 1, I will be glad to follow your own reasoning about that test, and answer all the other questions you raised in your last comments. But, please, one thing at a time.


    (1) Rossi Lugano/early demo's revisited. (technical)

    (2) Rossi Lugano/early demo's revisited. (technical)

  • Here's your plot.


    Thanks, so much.


    Well, now we can use the time evolution of (Emet+Evap) to estimate Evap.


    We know that Evap=0 until Tout is<100°C, that is up to the time tb=37 s. At this same time Emet is 370 kJ, therefore we can assume this value as the level of energy stored in the metal which allows the water to boil. Until the time ts=57 s, when the power is completely switched off, the curve (Emet+Evap) continues to increase reaching a maximum of 650 kJ, then it keeps decreasing due to dispersed heat. Finally, at time tf=57 s ca. - when the flooding begins - (Emet+Evap) is 610 kJ. By considering that at that time the water is still boiling, we can deduce that Emet is at least 370 kJ, so that Evap<610-370 = 240 kJ.


    As for the Evap curve, it can be approximated by a straight line which rises from zero (at t=37s) up to 240 kJ (at t=57s), and remains at this value thereafter. Emet can be obtained by difference.


    Does it sound reasonable to you?


    May I also ask you to include these two new quantities (Evap and Emet) in the energy graph? A curve representing (Ecool=Eout+Evap) would be also meaningful, because it represents the total heat carried away by the coolant. Thanks in advance.


    This last evaluation does finally allow to answer your starting question:

    - Roughly how much water do you think was still contained inside the device after the flow stopped?


    Assuming Evap=240 kJ, the heat of vaporization being 2257 J/g, it follows that the maximum mass of water which could have evaporated was 106 g. This is about 10% of the water inventory inside the Ecat, therefore at the end of the boiling phase, almost 90% of the water is still inside the device.

  • Why not like this?

    (honest question, that's how I tried to calculate it earlier today)


    Well done! That's a good way to esteem the Pvap at the onset of boiling, when the resistors are still powered on and Tmet is close to its maximum value.


    My estimation was instead about the maximum Evap along the entire 20 minutes of the boiling period. The value of 240 kJ corresponds to an average Pvap of 200 W, which gives the straight line I suggested before, if it is supposed to stay constant for the entire boiling period. But it was just a first order approximation.


    Our two methods can be joined in order to get a even better estimation, just drawing a line for Pvap starting with a value of 334 W a t=37s and decreasing to zero at t=57s, whose integral is 240 kJ.


    Are you able to do that?


    --------------- Eta:

    A simpler way to take into account both our estimations, is to assume a linear Pvap going from an initial rounded up value of 350 W (at t=37s) to a final value of 50 W (at t=57s), considering that there was still some boiling when the flooded started. The resulting average value would still be 200 W.

  • I'm generating the plots with computer code (I'm not using a spreadsheet) with as little "baked in" values as possible and also trying to limit complexity to keep it manageable and less prone to errors, so I ended up using your initially proposed method and dropping mine or the idea of combining both. Thus, below is the resulting graph.


    OK, that's enough. Thank you again.


    The average Pvap=200 W of my method is well confirmed by your initial 334 W, so it's not necessary to complicate too much your computer code.


    Just a few words of comment at the end of this work. IMO the final curves you posted above describe a realistic time evolution of what could have happened on the evening of December 16, 2010, in a warehouse in the periphery of Bologna. All the curves follows the expected behavior in accordance to the usual physics. The only strangeness is the little bump in the (Emet+Evap) curve, which in turn reverberates in the Emet curve, but it could depend on a misalignment of the other quantities used to compute (Emet+Evap). This model keeps valid as many as possible of the info provided in the Levi's report, but it adds the new basic assumption that the water tap has been closed at 17:47 (real time) and fully reopened almost half an hour later, at 18:14. The power to the electric heaters has been partially reduced at 17:58, and totally switched off at 17:03. The heat accumulated in the metallic parts close to the electric heaters in the period of no flow and power on has been sufficient to maintain the boiling temperature for 10-15 minutes more.


    This is a completely different interpretation of the Test 1 with respect to the one provided in the calorimetric report issued with the UniBo logo in January 2011, where the maintaining of the boiling temperature for about 15 minutes was presented as the effect of the generation of more than 9 kW of heat in self-sustaining mode by an alleged nuclear reactor based on controversial phenomena, denied by the mainstream science.


    So we have now two different interpretations. If you like to add a third one, I'm ready to examine and discuss it, otherwise I would like to know which one of the first two is more convincing for you.

  • This is a completely different interpretation of the Test 1 with respect to the one provided in the calorimetric report issued with the UniBo logo in January 2011, where the maintaining of the boiling temperature for about 15 minutes was presented as the effect of the generation of more than 9 kW of heat in self-sustaining mode by an alleged nuclear reactor based on controversial phenomena, denied by the mainstream science.


    So we have now two different interpretations. If you like to add a third one, I'm ready to examine and discuss it, otherwise I would like to know which one of the first two is more convincing for you.


    Ascoli,


    To be clear; you think there was nefarious and purposeful intervention with the water flow and power application, designed to skew the end results so as to appear overunity?


    Not choosing sides here. In fact you have been nothing short of masterful in getting this to where you did. And who can not be impressed with Can and his talents? Great job by both. Let the better science argument win I say. Wish I could judge who is right, and who not, but guess I will have to stick with my old appeal to authority. :)

  • Convective heat transfer correction


    As stated in my previuos post I saw a large difference between the convective heat transfer coeeficient presented on page 16 of the Lugano report for zone 5 of the rib area on page 16 and the one I calculated for zone 5.

    The Lugano report gave a value of 12.75 for zone 5 while i calculated (for the slightly lower corrected zone temperature) a value of 14.52.


    Since page 16 the Lugano report gives the values of all the parameters from which the convective heat transfer coefficient of zone 5 was calulated I could compare those with the values I used.

    Both are given in the following table :


    Coefficient-----------Lugano-------------Recalculation


    D-------------------------0.02----------------------0.02

    g--------------------------9.81----------------------9.81

    B--------------------------1.90E-3-----------------2.18E-3

    v--------------------------4.00E-5-----------------2.74E-5

    a--------------------------5.90E-5-----------------5.88E-5

    k--------------------------4.10E-2-----------------4.14E-2


    If we compare the values then it can directly be seen that there is a large difference in the values of the viscosity v.

    It turns out that I wrongfully used the tabulated values of the dynamic viscosity instead of the kinematic viscosity .


    From the values it can also be seen that the Lugano team used for the expansion coefficient the value 1/T (T being the film temperature) instead of the real tabulated values for air.

    As a third remark it can be seen that they used only two digits accuracy as can be seen by the trailing zeros of their values. As alreade mentioned in an earlier post these roundings can add up to inceased errors in the calculations.


    I now have to update, based on the kinematic viscosity, all convective heat transfer coefficients used in the Excel sheet of the Lugano dummy run recalculation.

  • [...] This model keeps valid as many as possible of the info provided in the Levi's report, but it adds the new basic assumption that the water tap has been closed at 17:47 (real time) and fully reopened almost half an hour later, at 18:14. [...]


    It's a big assumption. Is it entirely consistent with the observed trend of inlet water temperature?


    For example, what could have caused it to decline at an apparently accelerating pace before the water flow got interrupted?


    I've manually equalized the temperature steps for that part of the graph to make this clearer (assuming that in the original photographed plot every pixel on the vertical axis represented a fixed temperature step, which should have been the case).



  • It's a big assumption. Is it entirely consistent with the observed trend of inlet water temperature?


    Yes, indeed, very big. And IMO is entirely consistent with the experimental evidences and the outcomes of the above model.


    I called it "assumption", but I should have used "deduction", considering the clear evidences in favor of a water stopping. Not only because of the typical heating trend of Tin, which clearly indicates an asymptotic progressive warming toward Tamb, but also because it starts just when Tout begins to rise again.


    Quote

    For example, what could have caused it to decline at an apparently accelerating pace before the water flow got interrupted?


    I don't think that the decline phase can compromise the significance of the rising one. But your question is intriguing, so I tried to imagine a possible explanation. Here is my best guess.


    In the calorimetric report, we can read: "Before igniting the reactor the water flux was set and measured by collecting, and then weighting, an amount of water in a container in a given time. The measured flux was of 168 +/- 2 g in 45 +/- 0.1 s."


    The phrase "the water flux was set" suggests that there was a precise level of water flux to be set. In my opinion, this level was the flow that should have given a power out of 10 kW, assuming dry steam at the outlet. Considering a delta T of 85°C, as indicated in the report, and the evaporation entalpy of 2272 J/g, each g/s of water flux would have been equivalent to: 85 x 4,185 + 2272 = 2628 W/(g/s). Therefore a power of 10 kW would have required a water flux of 3,805 g/s. So, it was first necessary to open the water tap as much as necessary to get that flux, at the specific pressure of the water system at that time.


    Consequently, after the data acquisition system was turned on, the water tap was slightly opened and held in this position for a few minutes, until the water has started to escape from the end of the outlet tube. At that point, the water flux was measured by weighting the water poured into a container over a given period of time. If the weight was significantly lower than the target value, the handle of the water tap was rotated by a fixed angle, the container empted, and all the operations repeated.


    This way of working would also explain the reason why the time base used to fill the container was set to the strange and unusual value of 45 s. I suspect that a normal watch was used to measure time, and that a time base of 45 s would have allowed to complete a measuring step – filling, weighting, pouring and rotating - in a complete turn of the second's hand, facilitating in this way the control of the timing.


    Thus, it was established that the target value for the water mass was 3.805 x 45 = 171 g in 45 s. When the fairly close weigh of 168 g was measured, it was decided to switch on the heaters. It happened at t=7s of your graphs. Thereafter, the curve of Tin has two more downward steps with about the same length followed by a much longer lowest level, which is the expected trend for a cooling down at a constant flow.


    So, this setup procedure would explain both the accelerating pace of the downwards steps up to t=7s, and the subsequent decelerating pace.


    Is it reasonable for you? Any other objection?


    Going a little further. After switching on, it was expected that temperatures would rise on the PC screen, but it didn't happen, probably because of the wrong setting of the acquisition timestep. After a while, the time step was set at 10 s, and the first real point was plotted on the T graph.


    If you have time and possibility, it would be useful to have a graph with the experimental data (power in and temperatures) plotted in function of the real local time, and starting from the presumed time when the data acquisition system was switched on, with these actions marked on it.

  • To be clear; you think there was nefarious and purposeful intervention with the water flow and power application, designed to skew the end results so as to appear overunity?


    No, not in order to appear overunity. For this minor (if it can be called this way) goal, it was sufficient to declare that the exiting flow was dry steam, so that the water flow of 3,73 g/s (168 g in 45 s) was stated to be equivalent to 9810 W, versus an input power of 1120 W, with a COP of almost 9. Conversely, the intervention on the water flow and power application was intended to induce the convincement that the device was able to generate almost 10 kW of nuclear energy without the support of any external source, i.e. that it was able to operate in the so called self-sustaining mode (infinite COP) for about 15 minutes.


    Quote

    Not choosing sides here. In fact you have been nothing short of masterful in getting this to where you did. And who can not be impressed with Can and his talents? Great job by both. Let the better science argument win I say. Wish I could judge who is right, and who not, but guess I will have to stick with my old appeal to authority.


    Which two sides? Do you intend *can* and me? I don't think we are in competition. I did this work with a cooperative spirit, and I think the same was for him. He has been the best interlocutor I could have find, because, beyond his technical talents, he remains open to give credit to the protagonists of this story, so compensating for my negative bias on them. This relieves me from the burden to find by myself all the possible objections to my own hypotheses.


    For the moment, unless *can* provides a third explanation, the two sides corresponds to the interpretation of the December 2010 test contained in the Unibo report and the one described by the graphs plotted by *can* on the basis of my indications. The scientific authority is entirely on the first side. Does it means that you stick with the interpretation reported by UniBo?