On Wed, Jun 29, 2011 at 8:21 PM, Mark Iverson <zeropo...@charter.net> wrote:
> ** > > I did as you suggest and searched for '2-phase flow', and even refined it > by adding "steam quality" to the search terms... I'm sorry to disappoint > you, but it only took the first two references I looked at to satisfy me > that your explanation here is very unlikely, if not a total guess. > Not a total guess. The paper I had looked at is: Wang et al., "Photographic Study on Two-Phase Flow Patterns of Water in a Single-Side Heated Narrow Rectangular Channel", J Eng Gas Turbines Power 133 (2011) 052907. These are vertical channels (like the chimney), and they identify 4 stages within the 2-phase stage: "*Four discernible flow patterns, which names dispersed bubbly, coalesced bubbly, churn flow, and annular flow are observed."* * * Conditions are not the same as the ecat, but the paper was enough to suggest to me that a mist is reasonable. The photos of annular flow, at vapor speeds not that different from the ecat (with 1 inch tube), show droplets entrained in the flow. We don't know what is inside that chimney. It could be coiled tubing with a small diameter, which would produce higher speed of vapor, and a greater percentage of entrained drops. Or maybe he has concealed some kind of atomizer in the chimney. Or maybe a vertical chimney with a larger diameter produces more entrained drops. Who knows. What we do know is that liquid water has to get out of the chimney if it is not completely vaporized. Even if most of the liquid is along the walls, it's not clear what we would see at the output of a small opening. The gas speed through a 1 inch opening would be several hundred cm/s (depending on the degree of vaporization), and if the valve at the top of the chimney has a smaller opening, the speed would be even higher. The gas would expand at the exit and might entrain the water right there to form a fine mist. You can produce something approaching mist from 100% liquid by holding your thumb at the end of a hose, or with a suitable attachment. Most importantly, when they open the valve at the top of the chimney to examine the steam, they don't close the valve to the hose, which is vertically lower on the chimney. It is therefore entirely plausible that what comes out at the top contains considerably less liquid than what is forced through the hose lower down. You are right though to say that I don't know what is actually going on in that thing. The point is that what has been shown to us is not convincing evidence of dry steam. And if it were dry steam, there are very easy ways to prove it. Measure the volume flow rate. Reduce the input flow rate and see if the steam temperature climbs. The fact that they don't prove it when they could is very suspicious. Yes, 2-phase flow does happen in steam generation systems, and there's a > shitload of research on it primarily because of boiling water reactors which > produce the majority of the planet's electricity, but you have NO specifics > as to exactly how the 2-phase flow supports your CLAIM that there is alot of > entrained liquid water in Rossi's system, nor any third-party supporting > references to support your position. > It's Rossi's invention. The burden of proof is on him. He has no specifics to support his claim that it is dry steam. My claim is simply that if the power is lower than 5 kW but higher than 600W, the fluid has to be a mixture of 2 phases. I don't need references for that. And I argue with less certainty that what Rossi has shown us is at least consistent with a mixture of phases. As the ecat makes the transition from pure water to pure steam, it has to go through a stage where there is a mixture of phases. Why doesn't Rossi show us that stage so we can see how it changes as it becomes drier over what must be a period of at least tens of minutes. That's yet another way he could make his claim of dry steam more credible. And another thing he has not done.
