A projection an-isotropic spectrum method for inflow turbulence of Large Eddy Simulation in natural ventilation of buildings

The inflow boundary turbulence generation procedure is a critical topic for Large-Eddy Simulations (LES) in accurately simulating natural ventilation. The present study focuses on the turbulence energy spectrum, generated by the synthetic spectrum method for the fluctuating inflow velocity of LES. A projection algorithm is proposed for modifying the previous spectrum method to sustain the target turbulence spectrum, which is then validated by channel flow,airflow around the building and cross ventilation. The results show better performance in comparison with the previous spectrum methods. This validated procedure is then also applied to the LES calculations for building single-sided natural ventilation with two openings. Results indicate that the instantaneous flow change rate around two openings was specifically shown to have back and forth oscillation between positive and negative values, a valuable finding for future building natural ventilation designs.

Automated summary

The study focuses on turbulence energy spectrum of fluctuating inflow velocity in LES, proposing a projection algorithm to modify the previous spectrum method. The validated procedure showed better performance and revealed specific oscillation patterns in flow change rate around openings in building natural ventilation design.