Accurate and Faster Than Real Time Simulation of Indoor Airflow by Using Fast Fluid Dynamics

The Multizone model is one of the most popular models for simulating indoor energy and airflow; however, the basic problem of this model is that it cannot provide detailed and accurate airflow characteristics in the computational domain. To obtain the detailed airflow information, CFD model can be used but its high computational cost restricts the applicability of this method. Therefore, it is necessary to develop a model which can provide detailed airflow information with a reasonable accuracy and computational time. In this study, Fast Fluid Dynamics (FFD) method which has an unconditionally stable algorithm is proposed. To investigate the functionality of FFD model, four case studies of flow in a lid-driven cavity, flow in a plane channel, natural flow convention and forced flow convection are analyzed and the results are compared and validated with the results of CFD model, experimental data and analytical solution. The main focus of this study is increasing the simulation speed of FFD algorithm. For this purpose the sequence of equations has been modified and an efficient numerical method has been applied to solve the equations. Using the proposed FFD solver the simulation time of the case studies has decreased between 52 to 94 percent compared to the CFD and a faster than real time simulation has been achieved on a regular computer system.