Here is an interesting approach to what I assume is cold fusion: Huang, B.-J., et al., *Excess Energy from Heat-Exchange Systems.* J. Condensed Matter Nucl. Sci., 2022. *36*: p. 247-265.
https://lenr-canr.org/acrobat/BiberianJPjcondensedzi.pdf#page=257 Only a few people have tried this. Long ago, Mallove and I investigated a cavitation reactor at Thermodynamics, Inc. As far as we could tell, it produced excess heat. Usually around 3% but sometimes up to 17% as I recall. In the last year or so they installed an excellent industrial scale flow calorimeter designed by the Dean of Mechanical Engineering at Georgia Tech. The results from that seemed definitive to me, but I do not think the Dean signed off on them. I don't know what happened after that. As I recall, our investigation of Thermodynamics was one of the things that triggered the founding of this discussion group. The cavitation reactor at Thermodynamics resembled a vortex in some ways.
