Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 53 Issue 3 (Special Issue) 2021 05 22 Accurate and faster than real-time simulation of indoor airflow by using fast fluid dynamics Accurate and faster than real-time simulation of indoor airflow by using fast fluid dynamics 1839 1860 3865 10.22060/mej.2020.17222.6538 FA Mirmasoud Seyedi MSc student, Tarbiat Modares University Hadi Pasdarshahri Assistant Professor, Faculty of Mechanical Engineering, Tarbiat Modares University Journal Article 2019 10 15 The multizone model is one of the most popular models for simulating indoor energy and airflow; however, its basic problem is that it cannot provide detailed and accurate airflow information. Computational fluid dynamics can be used to obtain detailed airflow information but is restricted due to its high computational cost. Therefore, it is necessary to develop a model which can provide detailed airflow information with reasonable accuracy and computational time. In this study, fast fluid dynamics, which has an unconditionally stable algorithm, is proposed. To investigate this model, four case studies of flow in a lid-driven cavity, flow in a channel, natural and forced flow convention are analyzed, and the results are compared and validated with computational fluid dynamics, experimental data, and analytical solution. The main focus of this study is increasing the computational speed of fast fluid dynamics. For this purpose, the sequence of equations has been modified and suitable numerical methods have been applied to solve each equation. Using the proposed fast fluid dynamics solver, the simulation time of the case studies has decreased between 52 to 94 percent compared to computational fluid dynamics and faster than real-time simulation has been achieved on a conventional computer system. The multizone model is one of the most popular models for simulating indoor energy and airflow; however, its basic problem is that it cannot provide detailed and accurate airflow information. Computational fluid dynamics can be used to obtain detailed airflow information but is restricted due to its high computational cost. Therefore, it is necessary to develop a model which can provide detailed airflow information with reasonable accuracy and computational time. In this study, fast fluid dynamics, which has an unconditionally stable algorithm, is proposed. To investigate this model, four case studies of flow in a lid-driven cavity, flow in a channel, natural and forced flow convention are analyzed, and the results are compared and validated with computational fluid dynamics, experimental data, and analytical solution. The main focus of this study is increasing the computational speed of fast fluid dynamics. For this purpose, the sequence of equations has been modified and suitable numerical methods have been applied to solve each equation. Using the proposed fast fluid dynamics solver, the simulation time of the case studies has decreased between 52 to 94 percent compared to computational fluid dynamics and faster than real-time simulation has been achieved on a conventional computer system. https://mej.aut.ac.ir/article_3865_866d90e0921ac7b024b47d672445a086.pdf