Fluidyne Engine R&D


These are Stirling cycle engines with a fluid piston acted upon by a heat-induced pressure oscillation resulting from cyclic heating and cooling of a fixed amount of a working gas (air) inside the engine.

First Fluidyne

1st Fluidyne  A tiny resistor-heated fluidyne was made of vinyl and brass tubing and some fittings from the hardware store; and it provided encouragement to build larger, more-powerful engines.

Second Fluidyne

2nd Fluidyne A four-inch (100 mm) fluidyne made (mostly) of four-inch Schedule 40 PVC drain pipe and diesel truck exhaust tubing followed.

Going Global

Teams An e-mail from Pakistan asking for guidance in building a four-inch fluidyne engine prompted me to invite everyone interested to form teams and join in the development. You can see some of those teams’ work here.

A Shallow-Well Pump Design

3rd Fluidyne A shallow-well (5m) design was produced in response to a request from a group in Argentina who were interested in pumping relatively small volumes of water for vinyards in Mendoza Province.

Epiphany – An In-Line Fluidyne

4th Fluidyne An “ah-ha!” moment ocurred immediately after I sent the pump design above to the group in Argentina. I finally realized that the cold-side “piston” wasn’t really a piston at all.

Building an In-Line Prototype

5th Fluidyne Building the in-line fluidyne prototype was a bit of an adventure since I needed to turn a part on a lathe – a tool I'd never used before. Here are photos of the part being made on my new lathe and a complete set of parts for the first in-line engine.


Findings Summary of findings – what I’ve learned that might help others.

Copyright © 2011 Morris R Dovey

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