Hydradyne Engine Evolution
This engine converts heat energy to the mechanical energy needed to drive magnetohydrodynamic (MHD) generators for production of electricity. This page attempts to provide a grasp of the engine, and leaves the specific details of electricity generation for another page.
The starting point was the fluidyne engine shown above at top left. If you haven’t seen it before, you can get up to speed by reading my fluidyne web pages. You’ll need to understand that material to have any chance of understanding what you see here.
The engine shown at top center was the result of a flight of fancy. I added a second pair of hot and cold heads to the engine to produce an engine that doubled the push-pull of the original fluidyne, but seemed useless because I didn't see any way to get the power out of the engine.
After I'd sketched the two-headed engine, I realized that the water contributed nothing and that the engine would run even better without it. At top right is the engine without any fluid piston at all. It still looked pretty much useless, but I was pleased to have reduced the number of moving parts to only one and the number of places where the engine needed to be heated also reduced to a single point in the middle of the U-tube.
About this same time, I realized that I could increase the power considerably by replacing the air in fluidynes with supercritical water. I've provided some information about this in my hydrodyne web pages.
The only reason ever for the U-shaped tube was to allow using a fluid piston. Since a piston was no longer needed, I straightened out the tube to keep all forces in a straight line.
I really liked this fourth configuration. It seemed perfectly suited to be placed at the focal line of a parabolic trough for solar-powered operation with the cold heads extended beyond the ends of the trough (although it's worth noting that it could run continually if the central “hot head” were located in a nuclear pile).
Everything up to this point was a lot like scratching a mosquito bite - it provided some momemtary satisfaction/relief, but resulted in nothing more than an intensified itch. The engine was simple, compact, efficient, powerful, and (apparently) quite useless.
Then Daniel Connell, a Facebook friend from Christchurch NZ, suggested using a fluidyne with an MHD generator to produce electricity - and everything fell nicely into place. My “useless” hydradyne (which Dan didn't know about) seems to be a near perfect driver for MHD electric power generation. If you think that might be interesting, click on “Solar” below and follow the “Generators” link.