Parametric Analysis of a Stirling Engine Using Engineering Equation Solver

Abstract The Stirling engine is a clean energy source that converts heat into work efficiently with a theoretical thermal efficiency equal to that of the Carnot engine. As an external combustion engine, there is no limitation on the type of fuel source chosen to power the Stirling engine—so a wide range of unusual fuel sources may be used. This paper describes a program created in Engineering Equation Solver (EES) that is designed to create a power output matrix and a parametric analysis for any Stirling engine—whether alpha, beta, or gamma configuration—and is developed as a tool for use in a Senior Design project at SUNY New Paltz. Upon successful completion of this code, EES will compute a resulting power output matrix and P-v and T-s diagrams. The resulting power output matrix is two-dimensional: one dimension is an array of Revolutions Per Minute (RPM) values from 100 rpm to 1,000 rpm; the second dimension is an array of compression ratios. This power output matrix is created by utilizing the Parametric tables in EES. The Nasa Ideal Gas Library within the EES program contains 1,262 ideal gases to be chosen as the working fluid. The thermodynamic properties of these gases were recorded in 2002 at the Glenn Research Center. The thermophysical property functions in EES calculate the thermophysical property values at each state using the ideal gas assumption. The purpose of this program is that the user will input the length and bore of any chosen cylinder, as well as the hot and cold temperature values, to determine a power output matrix that varies with compression ratio and RPM, and then perform a parametric analysis for the Stirling engine. To prove the effectiveness of EES in designing and analyzing thermal systems, there is survey data completed by undergraduate mechanical engineering students who are using EES in their Thermal System Design course at SUNY New Paltz.