A potent numerical model coupled with multi-objective NSGA-II algorithm for the optimal design of Stirling engine

In this article, a novel numerical model of the Stirling engine encompassing a potent loss mechanism coupled with the NSGA-II algorithm is proposed. Multi-objective optimization of GPU-3 Stirling engine was performed using a class of genetic algorithms, namely NSGA-II, with five decision variables to minimize the losses and increase the power output and efficiency of the GPU-3 engine. Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) and Combinative Distance-based Assessment (CODAS) decision-making approaches were used to obtain the optimum solution from Pareto optimal space. Furthermore, the optimization results were compared with the experimental results of the GPU-3 Stirling engine. Results from the multi-objective optimization effort indicate that output power increases by approx. 500 W and efficiency enhances by approx. 5%, whereas losses decrease by 516 W. Later, to demonstrate the model's design capability, the developed model and optimization approach, i.e. (NSGA-II), is utilized to develop an optimal design of a beta-type free piston Stirling engine (FPSE) with an indicated power of 10 kW. After optimizing a combination of twelve operating and geometric parameters, the Stirling engine that yields a net power output of about 7.95 kW with a thermal efficiency of about 30% is developed. This work presents a novel and powerful numerical method for the optimal design of Stirling engine. (C) 2022 Elsevier Ltd. All rights reserved.

Automated summary

This article proposes a novel numerical model that combines a strong loss mechanism and the NSGA-II algorithm for the Stirling engine. Multi-objective optimization is performed on the GPU-3 Stirling engine using the NSGA-II algorithm, aiming to minimize losses and increase power output and efficiency. The optimization results are compared with experimental results, and the model is also applied to optimize the design of a beta-type free piston Stirling engine.