Modelling of internal environmental conditions in a full-scale commercial pig house containing animals

Abstract

In large livestock houses, controlling the internal environmental condition is a key factor for enhancing livestock productivity. The basis of thermal comfort, contaminants, and ventilation efficiency is the internal air flow, which can be controlled by the ventilation system. Field experimentation is a challenging method for analysing air flows due to limited number of measurement points, cost, unstable weather conditions, and experimental errors. Alternatively, computational fluid dynamics (CFD) have been extensively used to overcome the limitations of field experiments by means of their ability to artificially control experimental conditions and the ease with which structural configurations are modified. Most of the previous CFD simulations have regarded livestock structures as two-dimensional or simplified three-dimensional domains and complicated configurations that include animals have been ignored in simulation models. However, the presence of animals in commercial livestock buildings can significantly influence air flow patterns and internal environmental conditions. In this study, a full-scale commercial pig house was modelled to investigate the ventilation problems during the cold season. The simulation of pigs, and specific configurations of the ventilation system, was considered to improve the reliability of the CFD model. The CFD computed air temperature showed a −4.4% error compared to the field experimental data and this model was used to enhance the internal environmental conditions in the existing pig house by changing ventilation designs by sealing the entrances and reducing the size of inlet area, resulting in 24% improved thermal uniformity.