RESUMO
Ventilation systems used in swine facilities deserve to be studied because they directly affect productivity in the pig farming sector. Bearing this in mind the uniformity of air distribution and temperature is essential to animal welfare in this breeding environment. Thus, the purpose of this study was to identify whether changes in air entrances and exhaust fan positioning could influence air velocity and temperature distribution. The experimental data were collected in a commercial full-scale sow facility. Validation was carried out by comparing the simulated air temperatures and data measured in the field. These results showed agreement between data with a maximum relative error of approximately 3 %. The real settings showed a gradual increase in the air velocity from the air entrances and dead zones due to the change in airflow direction. There was no difference when the positioning of the exhaust fans was altered or was maintained in the original air entrances. The proposed arrangement with only one air inlet reduced the areas of low air movement as a consequence of the change in flow direction. Furthermore, the variables have the same pattern along the transversal plane. The simulations showed that the position of the air inlets had a higher influence on temperature distribution.
Assuntos
Animais , Bem-Estar do Animal , Temperatura , Ventilação , Metodologias Computacionais , SuínosRESUMO
Ventilation systems used in swine facilities deserve to be studied because they directly affect productivity in the pig farming sector. Bearing this in mind the uniformity of air distribution and temperature is essential to animal welfare in this breeding environment. Thus, the purpose of this study was to identify whether changes in air entrances and exhaust fan positioning could influence air velocity and temperature distribution. The experimental data were collected in a commercial full-scale sow facility. Validation was carried out by comparing the simulated air temperatures and data measured in the field. These results showed agreement between data with a maximum relative error of approximately 3 %. The real settings showed a gradual increase in the air velocity from the air entrances and dead zones due to the change in airflow direction. There was no difference when the positioning of the exhaust fans was altered or was maintained in the original air entrances. The proposed arrangement with only one air inlet reduced the areas of low air movement as a consequence of the change in flow direction. Furthermore, the variables have the same pattern along the transversal plane. The simulations showed that the position of the air inlets had a higher influence on temperature distribution.(AU)
Assuntos
Animais , Ventilação , Temperatura , Bem-Estar do Animal , Metodologias Computacionais , SuínosRESUMO
Este trabalho apresenta um modelo Fluidodinâmico Computacional tridimensional para simular a dispersão de substâncias solúveis em rios. O modelo pode predizer o impacto causado pela ocorrência de múltiplos pontos de emissão no trecho estudado. O código numérico para o modelo matemático foi desenvolvido em linguagem Fortran. Os resultados mostram que a metodologia proposta é uma boa ferramenta para a avaliação do impacto ambiental causado pela emissão de efluentes em rios. O software é bastante rápido, especialmente quando comparado com outros pacotes de CFD disponíveis comercialmente. Foram feitas comparações entre os resultados numéricos e dados experimentais coletados no rio Atibaia. Os resultados numéricos apresentaram uma boa concordância com os dados coletados experimentalmente.
This work presents a three-dimensional model for the dispersion of effluents in rivers using Computational Fluid Dynamics (CFD) techniques. There are several models in the literature, some of which even analyze complex flows. They are however restricted to small river sections. The main contribution of this work is that it proposes a new software capable of predicting the dispersion of effluents in very large open channels. The model is very fast, an unusual feature of CFD models. Due to this, it is possible to predict the dispersion of substances in long sections of rivers with some kilometers in extension. Moreover, multiple emissions can be analyzed by the model, allowing its use as a predictive tool to analyze and guide management decisions on future industrial installations near rivers. Results for the dispersion of an inert emission in a river near Campinas (Brazil) were used to validate the model.