Assessment of modeling slatted floor as porous medium for prediction of ammonia emissions - Scaled pig barns

CFD has been increasingly applied in predictions of airflow and gaseous emissions in livestock buildings. In full scale pig barns, it is hardly applicable to model the slatted floor at actual size due to the quantity of small slots which leads to the extremely huge mesh number. This motivates the researchers to model the slatted floor as porous medium (POM). In this study, the effects of POM and slatted floor modeling (SLM) on air speed, concentration and emissions are investigated in a scaled pig barn (1:12.5). The results show that SLM generally provide better predictions of air speed than POM. POM can predict the air speed below the slatted floor appropriately while fails to predict the air speed at the point above the slatted floor comparing to the measurements. The prediction of ammonia emissions is comparable by using POM and SLM while both SLM and POM fail to predict the ammonia emissions for some cases comparing to the experimental measurements.