Simplified analysis of Stirling engines and heat pumps

Stirling machines are well suited to a simplified analytical technique in which the major variables are represented by linear combinations of sinusoidal or harmonic functions. Previous analyses of this type have, however, been unable to take into account some important aspects of the behavior of real engines, including the effects of heat transfer within the cylinders, pressure drop in the heat exhcangers, and leakage of gas from the working space. The new theory, developed at Oak Ridge National Laboratory, is able to treat the losses from these causes by representing the nonlinear terms responsible for the effects as a truncated Fourier series. The resulting analysis is mathematically accurate and, when implemented on a computer, from 10 to 100 times faster than a numerical solution to the same differential quations. The theory also realistically represents interactions between the various effects while identifying unambiguously the loss due to each one. 21 references.