Date of Award

2008

Degree Type

Thesis

Department

Mechanical Engineering

First Advisor

Ebiana, Asuquo

Subject Headings

Heat exchangers -- Thermodynamics, Heat-engines, Stirling engines

Abstract

A 3-space solution domain (gas spring + heat exchanger + regenerator) is adapted from the 2-space solution domain (gas spring + heat exchanger) in Kornhauser MIT test rig [25] by modifying the heat exchanger space to include a porous regenerator system. A thermal non-equilibrium porous-media model is employed for the regenerator. Extensive numerical simulations of the fluid flow and heat transfer phenomena under conditions of oscillating pressure and oscillating fluid flow inside the 3-space solution domain were performed using 1-D Sage and 2-D Fluent numerical codes. 3-space results of temperature, pressure and surface heat transfer variations, pressure-volume diagrams, energy conservation and thermodynamic losses are compared with 2-space results in order to observe the effect of the regenerator and with results obtained from the literature. An important and primary objective of this study is the development of an entropy-based thermodynamic loss post-processor to characterize the major thermodynamic losses inside the 3-space model. It is anticipated that the experience gained from this can be extrapolated to more complex systems like the Stirling engine with a view towards improving the optimization capability of Stirling engine analysis codes through better understanding of the heat transfer and power losses. It is also anticipated that the incorporation of a successful thermal non-equilibrium model of the regenerator in Stirling engine analysis codes, will improve our ability to accurately model Stirling regenerators relative to current thermal-equilibrium porous-media model

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