The most interesting new - but actually old - engine development (esp. for those who think LENR has a future in transportation) is the re-emergence of the Stilrling design. This engine design and the Brayton cycle, in general, never made the grade for commercialization - before now, at least.
Change is in the air... so to speak. Unfortunately China, once again, is making large engineering gains while we seem to be playing catchup. https://www.globaltimes.cn/page/202112/1243157.shtml Quote: "the basic prototype of China's first large-bore Stirling engine successfully conducted the recent performance test... at a rated power of 320 kilowatts with a power conversion efficiency of 40 percent, making it the most powerful Stirling engine known around the globe." There are few if any diesels which can return 40% efficiency but China got there on the first prototype, The reason that the piston-Sterling could potentially augment LENR is not well appreciated either. Basically it is because the Brayton cycle is inherently closed-cycle. The Stirling can be either piston or turbine based, but the piston config is what LENR can possibly optimize with few changes. IOW the closed-cycle is one way to expose a metal catalyst to a flow of hydrogen without combustion of the hydrogen itself. Thus, if the working gas contains even a small percentage of hydrogen and the piston crown is coated with nickel/palladium alloy, then extra heat could potentially be extracted - on top of the external heat of combustion which occurs else where in the design, The LENR would be a booster, so to speak, Will China be the first to realize this ? They did after all, report on replicating Arata and that was a decade ago. Jed Rothwell <jedrothw...@gmail.com> wrote: H LV <hveeder...@gmail.com> wrote: We don't really know how steam engines would have evolved because they were out-competed by diesel engines. As I recall, the last attempts to compete with Diesel engines was with steam turbines. This source says the Union Pacific actually made two steam turbine locomotives, and tested them, in 1939 and 1962.
