Performance of fast fluid dynamics with a semi-Lagrangian scheme and an implicit upwind scheme in simulating indoor/outdoor airflow

Computational fluid dynamics can be time consuming for predicting indoor airflows and pollutant transport in large-scale problems or emergency management. Fast (FFD) is able to accomplish efficient accurate simulation of indoor/outdoor airflow. FFD solves the advection term Navier–Stokes equations either by a semi-Lagrangian (SL) scheme an implicit upwind (IU) scheme. The SL highly efficient, but its first-order version not conservative introduces significant numerical diffusion. To improve accuracy, high-order temporal interpolation that only reduces dissipation dispersion errors also guarantees convergence speed should applied. Otherwise, IU instead could used solve term. minor diffusion, it may increase computation time. Therefore, this study investigated performance with using schemes comparisons experimental data two one outdoor results showed was overall more than In simulating airflow, both methods were robust predictions independent step sizes if Courant number less equal one. performed better large sizes. consumed 44%–61% computing