Chapter 5e - Function set simple - a Simple simulation of a specific Stirling engine configuration

From the flow diagram below we see that the main program sea (stirling engine analysis) first defines the system to be simulated in terms of the set of global variables set up by the define set of functions, as described previously. It then invokes either the function adiabatic which does an Ideal Adiabatic simulation, or the function simple to do a Simple simulation to evaluate the heat transfer and pressure drop loss effects. Function set 'simple' includes nine functions, all contained in separate m-files as shown. The four main functions are hotsim and kolsim to respectively evaluate the heater and cooler gas temperatures, regsim to evaluate the regenerator effectiveness and resulting enthalpy loss, and worksim to evaluate the pumping loss. The heat-transfer/flow-friction function set includes function reynum to evaluate the instantaneous Reynolds Number, and the three functions pipefr, foilfr and matrixfr to determine the various flow friction and heat transfer coefficients.



The dynamics of the solution algorithm lies in function simple, as shown in the following flow diagram. Thus the function set define specifies the operating conditions, including the temperature bounds th and tk. Since the temperature bounds of the working gas affect both the power output and efficiency, the simple routine invokes adiab, regsim, hotsim, and kolsim in a loop until convergence of the gas temperatures is attained.




The nine functions of the set simple are included in the following m-files (refer to the flow diagram above): [simple.m, hotsim.m, kolsim.m, regsim.m, reynum.m , worksim.m, pipefr.m, foilfr.m and matrixfr.m]. As before, these can be directly copied from this website and used in a system which has MATLAB installed.
Notice that there are a limited number of heat exchanger configurations specified. It is intended that the user will modify and augment this system as required for specific systems, and as more updated heat transfer correlation data becomes available.

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Stirling Cycle Machine Analysis by Israel Urieli is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License