CFD Simulations Of Cross Natural Ventilation Through An Apartment With Modified Inflow Boundary Conditions

Natural ventilation in buildings can improve indoor air quality and thermal comfort in summer and can reduce the use of air-conditioning. Traditionally the inflow boundary conditions for calculating natural ventilation used weather data from a meteorological station that is often in suburb. The hourly wind velocity from the meteorological station may lead to some errors due to discretized data on hourly basis. This investigation proposed a correlation method to modify the hourly wind velocity from the meteorological station into minutely data by using measured data on the rooftop of a building interested. A CFD simulation using unsteady RNG k-epsilon model was performed to calculate simultaneously the outdoor wind velocity and the cross-ventilation rate through an apartment in the building. The computed results of outdoor wind velocity and indoor ventilation rate were compared with the experimental data. The results showed that the CFD simulations with the unsteady RNG k-epsilon model and the modified inflow boundary conditions could accurately calculate the outdoor wind velocity variations and indoor natural ventilation rate.