Introducing an accurate thermodynamic modified model regarding time-dependent heat transfer for [formula omitted]-type Stirling engines

Abstract

The biggest concerns of researchers and developers of Stirling engine is providing an accurate, fast and low-cost thermodynamic model. Second-order methods despite high speeds and low costs, still require increased accuracy. In present study, in order to provide high accuracy modeling, a new model based on second-order methods was developed. For this purpose, the effectiveness of cooler and heater is calculated according to the instantaneous velocity of piston and mass flow at each moment of Stirling engine movement, and its effects on the working fluid temperature are considered coupled in the main equations. Other heat and work losses including hysteresis, shuttle effect, wall heat transfer, leakage and pressure drop are calculated separately and added to the main model. The sum of mentioned item converges by using a new solution algorithm and forms a Modified model. In order to validate the Modified model and its result, it was implemented on GPU-3 engine. Modified model Estimates the efficiency and performance of GPU-3 with an error of 3.4% and 0.2%, respectively compared to the experimental results.