An Initial Model for the Finite Displacement Response Characteristics of a Fluidyne Pump.
Abstract
This paper is the final report on the independent laboratory in house research (ILIR) sponsored work by the Harry Diamond Laboratories on the Fluidyne pump. The effort started with a survey of the extant literature on the subject, continued with experimental observations that led to a mathematical model, and has culminated with a comprehensive statement on the physical operation of the pump. The literature is particulary sparse on the subject; hence, only the basic references are cited. The report presents a detailed mathematical model of the fluid mechanical and thermodynamic processes occurring during oscillation. A positive-feedback simulation model is postulated that demonstrates, for the first time, physically why there is an onset of oscillations and subsequent sustained motion. This model is based on actual observations of the startup process in a prototype pump. The initially reported thermodynamic efficiency of this heat engine was less than 0.3 percent. Currently, Fluidyne pumps have demonstrated efficiencies of about 2 percent. The peak efficiencies, however, may theoretically approach 10 percent. The mathematical model has shown that large losses occur in the heat transfer to the working gas, heat losses to the displacer liquid, and friction in the output line. Improvements in these areas may dramatically improve the observed overall efficiency. The efficiency of the cycle itself, that is, the work done by the thermodynamic cycle relative to the output work, is on the order of 10 percent.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1979
- Accession Number
- ADA069159
Entities
People
- Tadeusz M. Drzewiecki
Organizations
- Harry Diamond Laboratories