Mary Yugo wrote:
The problem is simulating the nature of the manifold, with its very high thermal conductivity and large contact area between hot and cold sides. Taping together two hoses does not do this.Very well put. I think that's the main issue here.
You missed the main issue. I was testing for air convection in a pocket. I knew that the two pipes touching would not conduct a significant amount of heat. I believe I said that before, and again today.
Granted, there was no significant air convection with that string tent, although I did give the TC some space. My air pocket was larger by far than Rossi's would be, if he has one (which I doubt). Really, this is a non-issue. If someone would like to make a larger tent with a clear path between the hot body and a cold body, please do so. I'm sure you will still find no measurable effect. I could do that if someone would like to recommend a specific method. Not dry ice touching the hot water pipe 1 cm away from the TC. Some reasonable simulation of Rossi's system.
The other way to do this is by modeling. Use a computer instead of a real test. Everyone who has done that for the conduction problem has determined it is a non-issue.
Actually . . . for the conduction test, an ice pack around a copper pipe of hot water would be easy to arrange . . . That's a stable source of cold, until the ice all melts. One of those blue refrigerator pack things. I wonder how far upstream it should be? Easier than a blowtorch.
If the whole matter is sufficiently important and it's economically feasible to get a heat exchanger similar to Rossi's, that'd be the way to go.
After some consideration, I do not see what the heat exchanger has to do with these hypotheses. Perhaps it has to do with some other hypothesis. One at a time. Simply the experiment to explore the question. Do not use an entire heat exchanger if all you want to know is whether conduction is a significant fraction of convection in this system.
- Jed
