Simulations of air distributions in buildings by FFD on GPU

Building design and operation often requires real-time or faster-than-real-time simulations for detailed information on air distributions. By solving the Navier-Stokes equations and transportation equations for energy and species, Fast Fluid Dynamics (FFD) model can provide detailed information as a Computational Fluid Dynamics (CFD) model. Compared to the CFD, the FFD is 50 times faster with some compromise in accuracy. But the accuracy and speed of the FFD model can be further enhanced by improving its numerical schemes. In addition, it was found that the computing time of the FFD program can be reduced up to 30 times by executing on a Graphics Processing Unit (GPU) instead of a Central Processing Unit (CPU). Furthermore, the FFD simulation can be accelerated by optimizing the GPU code and by using multiple GPUs. As a whole, it is possible to perform real-time simulation for a moderate size building with 10⁷ grids and Δt = 0.1s using the FFD on GPUs.