Thanks Jed. If the water alone recovers 1.3 watts with average drive drive, and more resides within the vessel, then you are in great shape.
If you have the chance, I would greatly appreciate it if you could ask Dr. Mizuno about the measured flow rate. My earlier calculation using 9 liters per minute clearly suggests that the skeptics made a major error by using the 5 mm pipe. As the calculations show, they will find that kinetic energy and thus power transport will be 16 times as much as seen had they used 10 mm pipe assuming the flow rate is constant. As you know I am discussing this aspect of their report and hope to resolve the issue soon. I am confident in my analysis. I have approached the problem from a couple of different directions and keep getting the same result. Dave -----Original Message----- From: Jed Rothwell <[email protected]> To: vortex-l <[email protected]> Sent: Sat, Jan 10, 2015 2:42 pm Subject: Re: [Vo]:"Report on Mizuno's Adiabatic Calorimetry" revised David Roberson <[email protected]> wrote: Jed, looking at figure 6, the Oct 21 data I calculate that the average power is 1.3888 watts. That is 20 watts * 500 seconds / 7200 seconds = 1.3888 watts. Yes, that is the answer I got, in Table 1. However, bear in mind that is for the water alone. Not for the reactor, which has a slightly larger thermal mass than the water, and much worse insulation. Estimating that, I get 3.4 W total, on average. Based on a very rough estimate of unaccounted for heat losses and Newton's law of cooling I guess the actual average power is about 7 W. In other words, the reactor metal plus the water are recovering about half of the heat. If Mizuno applies that amount of power continuously what would you expect the temperature to do? With 1.3 W input I expect to see nothing, as I said in the paper on p. 9. That is, in fact, what I saw when I did a similar test. There is too much noise, and the water recovers only about one-fourth of the heat, as I said. So I figure you would have to input ~7 W continuously to see this temperature rise. Mizuno hopes to do that kind of simulation but I do not know when. Actually, now that ambient fluctuations are reduced, you might see 1.3 W in the reactor. That would put ~0.5 W into the water I guess, about twice as much as the pump. It might raise the water temperature by ~1 deg C after an hour or two. It is hard to say. The only way to find out is to do a test and measure it. My gut feeling is that the temperature would increase along a constant slope once the transients are settled down. Well, it increases for a while, but at low power it then soon stops rising as the calorimeter goes from being adiabatic to isoperibolic. That takes 1.4 hours at ~0.2 W. I do not know how long it takes at 0.5 W or 3 W. At any power level it must eventually stop heating, when losses equal input power. Losses increase with the rising temperature, per Newton's law. Also, can you verify that the water flow rate is actually nominally 8 liters per minute? That's what Mizuno said. I suppose he measured it when dumping out the cooling water. He had to change out the Dewar reservoir a couple of times. I think that is what the pump spec. sheet says. There is hardly any resistance, and no grade, so I guess it should be close to maximum performance. - Jed
