Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 55, Issue 1 (2019) 29-38 29 Journal of Advanced Research in Fluid Mechanics and Thermal Sciences Journal homepage: www.akademiabaru.com/arfmts.html ISSN: 2289-7879 Two-Dimensional CFD Simulation Coupled with 6DOF Solver for analyzing Operating Process of Free Piston Stirling Engine Alliche Ridha 1 , Announ Mohamed 1,* , Chetti Boualem 2 , Kermezli Tayeb 1 1 Laboratory LME, Medea University, 26000 Ain D’heb Medea, Algeria 2 Laboratory of Industrial Fluids, Measurements and Applications, University of Djilali Bounaama- Khemis Miliana, Aindefla, Algeria ARTICLE INFO ABSTRACT Article history: Received 15 December 2018 Received in revised form 19 February 2019 Accepted 22 February 2019 Available online 10 March 2019 This work focuses on developing a two-dimensional axisymmetric simulation of the entire free piston Stirling engine (FPSE) using ANSYS Fluent to evaluate its output power. The engine model used in this study is the Sunpower B-10B which is thoroughly investigated in different conditions including static and dynamic state. A six-degree-of- freedom (6DOF) solver is used for the first time in this study to solve the problem of fluid-structure interactions between the working gas and the rigid-bodies (Piston and displacer) and therefore enabling to determine accurately the piston and displacer amplitudes as well as the frequency and phase difference under the engine's operating conditions. Keywords: Free piston Stirling engine, ANSYS Fluent, fluid-structure interactions, 6DOF solver, static and dynamic state Copyright © 2019 PENERBIT AKADEMIA BARU - All rights reserved 1. Introduction Around the globe, a tremendous number of people are living in very remote and rural areas where access to electricity is very complex due to the lack of power networks whose installation is excessively costly. Therefore, to meet these people's need for electricity, the Stirling engine can be used as an environmentally-friendly solution because it converts renewable energies such as solar energy, biogas and biomass into electricity [1,2]. Moreover, this engine has proven to be as efficient as Carnot engine [3,4]. The Stirling engines fall into two types, the kinematic and the dynamic [5]. The Kinematic engine is easier to investigate compared to the later one because the piston and the displacer are connected to each other. This makes it possible to know their amplitudes as well as the difference phase. Alpha, beta and gamma Stirling engines are considered as kinematic engines. In the dynamic engine both the piston and displacer are free to move independently and their motions are coupled through the working fluid pressure which makes this type of engine more advantageous than the kinematic engine due to its simple structure [6], and the absence of the connecting rod which solves the * Corresponding author. E-mail address: moh_announ@yahoo.fr (Announ Mohamed) Open Access