Influence of Inlet Turbulent Characteristics on CFD Predictions of Indoor Flow Field and Ventilation Performance

The turbulent characteristics of the inlet of a ventilation system have great influence on the airflow characteristics and indoor pollutant distribution. However, the significance of inlet turbulence has not been sufficiently addressed. In order to understand such influence, this paper uses the standard k-ε model to simulate the airflow characteristics and indoor pollutant distribution of IEA20 benchmark test. The values of inlet turbulence intensity were changed from 4 to 20%. The simulation results are compared with the experimental data in the literature. At X = h/2, the difference between simulated values and experimental data increases with increasing turbulence intensity. At X = H − h/2, with the increase in air supply distance, the simulation value and the experimental data eventually show a certain error. The experimental data near the wall are negative, and the simulated values are positive. The effects of different turbulence length scales on the velocity field are also studied. This is further extended when considering the presence of indoor pollution sources.