Stirling Cycle Machine Analysis

This material is made available to us by Dr. Israel Urieli of Ohio University in Athens, OH.  The text has been edited to facilitate its use by non resident students of the Stirling Engine who cannot attend classes in person.  Please do not pester Dr. Urieli with questions regarding this site. He has a full teaching load plus several research projects.  Please post all questions for discussion of this site to the SESUSA knowledge exchange list server at sesusa@yahoogroups.com.  You must first subscribe to the list before posting.  Please see http://sesusa.org front page for a link to the list. Any questions that cannot be answered by the list members will be submitted to Prof. Urieli by the moderators for further consideration.  And Yes, it does look a lot like rocket science. © 2001, 2002 I. Urieli

Text: Stirling Cycle Engine Analysis, I Urieli, D M Berchowitz. (1984)
(Note that the text includes FORTRAN code of the computer simulation, however the program has been updated and rewritten in C on the SUN computer "condor")  This book is out of print, however some copies are kept on reserve in Alden Library at Ohio University. Furthermore, much of the material that is in the book has been updated and placed on this web site, so that you may not need to refer to the text for this course.  It may also be possible to get a copy from your local library through inter-library loan.  Many university libraries contain copies of this book.

The web page will develop around the analysis and computer simulation of single phase, piston/cylinder thermal power and refrigeration systems including thermodynamics, heat transfer and fluid flow friction.  This will require adapting and using a computer simulation program using ANSI C on a SUN computer "  In many cases the introductory and background material listed in the sections prior to the computer code will supply sufficient information for many to understand the processes.  We will also focus on aspects of Stirling engine design using techniques developed by Dr. Allan J. Organ, while at Cambridge University, England.
 

• Introduction. (Chapter 1)

Principle of Operation
Basic Engine Configurations
(Here we define the Alpha, Beta, and Gamma engine configurations and show typical examples of usage.)
 
• Isothermal Analysis. (Chapter 2; Appendices A, C.1, C.2, C.3)

(We define and analyse the Ideal Isothermal model of a Stirling engine, and discuss its limitations.)
Develop the Ideal Isothermal equation set
Schmidt closed form solution
Develop and test computer program modules ' define'
 
• Adiabatic Analysis. (Chapter 4; Appendices C.5, C.7, C.8)

(We find that the Ideal Isothermal model predicts that the heat exchangers of a Stirling engine are redundant, thus we cannot seriously use this model to predict the ideal performance of a real machine. We thus turn to an alternative model - the Ideal Adiabatic model. Unfortunately we find that there is no closed form solution to this model and we have to resort to computer simulation. Nevertheless we can gain various insights from using this model in particular with regards to the importance of the regenerator.)
Develop the Ideal Adiabatic equation set
Numerical solution of differential equations
Develop and test computer program modules ' adiab'
Case Study - The D-90 Ross Yoke-drive Engine
 
• . (Chapter 6; Appendix B)
• Simple Analysis

(This analysis approach uses the Ideal Adiabatic model as a basis to predict the real performance of the three heat exchanger sections, particularly with regards to heat transfer and pressure drop. This can then be used to do parametric analyses on specific machines.)
Heat transfer and flow friction
Methods of including losses in the analysis
Develop and test computer program modules ' simple'
 
• Scaling Parameters and Stirling Engine Design

This section is based on the significant new work by Dr Allan Organ of Cambridge University in England. We will define and examine the various scaling parameters relevant to Stirling engines, and show how to use these in developing a design methodology.

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The actual course at Ohio University in Athens, OH includes a set of tutorial computer program modules for simulating specific Stirling engine configurations. These have been written in the C language and are maintained on a SUN UNIX workstation, and each registered student is assigned a login directory to this machine. One of the students tasks will be to augment these modules to simulate and design the specific engine assigned, thus there is a need to become familiar with the entire simulation package. Currently the engine modules are for Alpha machines, including a Sinusoidal drive and a Ross Yoke-drive machine. The heat exchanger types include tubular, annular gap, and slot heat exchangers, and the regenerator matrix types include screen mesh and rolled foil matrices. Working gas types include air, helium, and hydrogen. All of these engine types are compatible with the SESUSA purposes and goals as stated in the introduction received upon joining the SESUSA list.

To go to Dr. Urieli's home page at Ohio U, click this link