Computational fluid dynamics modeling of the climate inside a chicken house

Abstract

Nowadays, most of chicken products are from a closed house system. Climate inside such chicken house can significantly affect chicken welfare and its productivity. Moreover, Thailand is in a tropical region where thermal stress is easily occurred. Suitable operating condition and chicken house design can help improve interior climate which can be evaluated by computational fluid dynamics (CFD) modeling technique. In this study, realizable k-ε model, energy conservation and species transport equations were applied to simulate the air velocity, temperature and relative humidity, respectively, inside the chicken house. The model was validated with measured air velocity, temperature and relative humidity inside the chicken house during real farming operation. Good agreements, based on the values of normalize mean square error (NMSE), between simulation results and measured data were found, except the air velocity beneath the deflectors. The deviation might be due to the limitation of the air velocity sensor and the capability to predict eddies due to jet flow of the turbulence model. The validated model was then applied to develop an operational guideline and design improvement to maintain the favorable indoor climate for chicken even in extreme environment. The effective temperature was considered as an indicator for suitable climates for the chicken. The results showed that the developed operational guideline for evaporative cooling pad and exhaust fans could help maintain favorable indoor climate in all weather conditions throughout the years. In addition, an installation of thermal insulation could help mitigate the heat transfer from the roof. A design modification to the wind deflectors could also increase the air velocity and improve the ventilation. With both thermal insulation and deflector modification, the effective temperature at the chicken level could be maintained within the optimal range even in severe weather condition. Furthermore, it also improved the uniformity of the indoor climate in the chicken occupied zone, and thus enhanced well-distribution of the chicken.