CFD simulation of vertical ventilation and optimal design of wind shield in nursery pig house

In order to study the environmental distribution law of the vertical ventilation nursery pig house in cold northern regions, the nursery pig house in Qiqihar City, Heilongjiang Province was used as the research object. Computational fluid dynamics（CFD） simulations were used to explore the temperature field and wind velocity field distribution under the conditions of no wind deflector and wind deflectors with different angles. Five cases were designed and analyzed, case 1 had no wind deflector,case 2 had cylindrical wind deflector, and case 3 to 5 were truncated cone-shaped wind deflectors with an angle of 60°, 45° and 30° between the bus bar and the bottom surface, respectively. The vertical ventilation model of nursery pig house was verified by experiment. The results showed that the coefficient of determination（R2） between the temperature field and airflow field of the vertical ventilation nursery pig house CFD model and the actual measured value reached 0.9268 and 0.0.8926,respectively, which indicated that the model had a high degree of simulation; when the wind deflector was added, the temperature difference in the animal occupied zone（AOZ） of the pig house would be reduced by 50.77%-71.39%, the temperature standard deviation would be reduced by 28.77%-62.32%,the coefficient of variation of airflow would be reduced by 28.60%-61.37%, and the standard deviation of mean age of air（MAA） would be reduced by 14.83%-43.40%. Baffles with different angles produced different airflow, which affected the distribution of temperature field, wind velocity field and mean age of air. This study could provide a theoretical basis for the optimal design and environmental regulation of the vertical ventilation structure of the nursery pig house in the cold northern regions.