Application of computational fluid dynamics to the prediction of airflow in a mechanically ventilated commercial poultry building

Heat-stressed poultry can suffer high mortality rates when air velocity in the microenvironment around the chickens falls below a minimum threshold level. The current designs of ventilation systems and buildings are able to create suitable air velocities in the zone occupied by animals and can be evaluated by computational fluid dynamics (CFD) techniques. However, it is still important to experimentally validate the CFD simulations. The objectives of this work were to develop four CFD simulations of airflows inside a mechanically ventilated commercial poultry building, by using different boundary conditions (corresponding to a single experimental scenario), and to validate the CFD simulations by comparing the simulated and measured air velocities. The different comparisons carried out between measured and simulated air velocities showed that the simulations provide reasonable predictions of the velocities in the commercial poultry building. The best fit between the CFD simulations and the experimental data was obtained when ‘air velocity’ at the inlets and ‘percentage of airflow’ at the outlets, both of which were calculated from the measured ventilation flow, were used as boundary conditions. Adjusting the CFD results by using at least 15 indoor air velocity measurements led to a more precise estimate of the mean air velocity at height of the birds. Air velocity at the height of the birds was 0.36±0.14 m s−1 obtained from measurements, 0.54±0.22 m s−1 obtained from the CFD simulations and 0.33±0.13 m s−1 from the adjustment of the CFD simulation results using 27 indoor air velocity measurements.