2009 Volume 43 Issue 3 Pages 227-237
We used aerodynamic technology to develop a ventilation system for a prototype chick incubator. We used computational fluid dynamics (CFD) to analyze the internal airflow and distribution of air within the incubator. We used local mean age (LMA) and local mean residual time (LMR) theory to examine the accuracy of the CFD model and to quantify the ventilation efficiency. The largest CFD error was only -3.5%, proving the reliability of the model for studying the ventilation efficiency of the incubator. We also compared the total mass flow rates of the inlet and outlet slots and examined the mass balance of the CFD model. The comparison showed an error of -0.8% at a ventilation rate of 100% and -1.2% at 50%. The CFD results show that the ventilation system improved the ventilation efficiency of the chick incubator. The incoming fresh air was evenly supplied to all cages via a duct and a diffuser installed in the central passageway, and contaminated air was exhausted through the outlet system before being diffused to the cages. The sizes of the inlet and outlet slots were very important in improving the uniformity of ventilation. The angle of the diffuser installed in the ceiling inlet was also critically important in maintaining a uniform air pressure and airflow at the inlet slots.