Indoor air flow motions caused by the fabric air dispersion system: A simplified method for CFD simulations

Abstract

The fabric air dispersion system (FADS) has many distinctive features and, when properly designed, can improve indoor thermal environment cost-effectively. In the present work, computational fluid dynamics (CFD) procedures were utilised to investigate the FADS in penetration mode (FADS-PM)-induced flow fields. The mean velocity method (MVel) is proposed to approximately model the supply air flow boundary conditions, which could greatly influence the computational accuracy of overall fluid flow simulations. First, the hypothesis of even velocity distribution at air inlet was validated by flow visualisation and experimental data. Second, the simulation results within the room under isothermal and non-isothermal conditions were compared with those obtained by the direction description (DD) method. Furthermore, the computational resources required were discussed. The results demonstrate that the MVel method performs as well as the DD method in predicting the distribution of airflow generated by the FADS-PM. The MVel method is more easily implemented without considering the physical configurations of the fibre and difficulties in generating grid meshes due to the large scale of length to depth. In addition, the MVel method can greatly reduce the demand for computational resources and save computational time. The results of this research can benefit engineering designers by providing a method that evaluates the overall quality of the FADS-PM-based air-conditioning system more efficiently.