ABSTRACT
Model experiments were performed under summer ventilation in windowless swine farrowing house to prove the relationship between ventilation method : (1) incoming jet direction, (2) incoming jet velocity under the constant ventilation rate and distribution of contaminant(carbon dioxide) concentration. The object chosen for study was a house with continuous slot inlets and dampers above both side wall and with outlets at the center of the ceiling. It was found that the incoming jet direction significantly (5%) influenced the distribution of contaminant concentration. It likewise showed that contaminant can be eliminated only by incoming jet direction even if ventilation rate is not changed. It was concluded that contaminant in pens and inside building was better eliminated when the incoming jet direction was 45deg. downward and its velocity was 4.5m.s-1 than in other ventilation method. This is because dimensionless concentration was smallest inside pen and building in the direction in which air directly flowed into the pens where the contaminant generated. When incoming jet direction was 45deg. and 60deg. downward, carbon dioxide tended to accumulate towards the direction of the gable end wall. When it was 30deg. downward. however, the tendency was the reverse. A correlation between turbulent energy and dimensionless concentration(DC) was also shown. No existing correlation, however, was found between kinetic energy of mean flow and DC.HomePage