Experiments with plunging cylinder liquid piston Stirling engines

Plunging cylinder liquid piston Stirling engines with flow restrictive seals were tested at atmospheric mean pressure and low temperatures. Two method of fluid level control within the plunging cylinders were investigated, and a higher temperature hot oil engine was operated. An engine was built with 5.75 in internal diameter cylinders with 22 in strokes, to be run in either a gamma or in an alpha configuration; in the gamma configuration, phase angle and pressure variations could be independently changed. The test results are presented and discussed. They show that for the specific construction techniques, proportions, and hot water temperatures investigated, cylinder speed remains essentially constant with scale-up