Many modern data centers utilize containment systems as a practical and inexpensive thermal management solution. In this paper we investigate the effect of various containment leakage ratios on the flow rates and the temperatures in a representative data center. The modular data center is an actual contained cold aisle system in an experimental laboratory. The numerical model is validated using experimental measurements presented in a previous study for uncontained and contained cold aisle data center configurations . The model takes into account the fan curves in the CRAC and IT-equipment.
A commercial CFD code is used to conduct this study. The k-ε model and the Boussinesq approximation are used to model the turbulent airflow and the buoyancy effect, respectively. An approximate overall leakage model in the cold aisle is used in this study rather than a detailed model where the simulated leakage sources include floor tiles, containment surfaces, and racks. Several parametric studies are conducted by varying the leakage ratios ranging between 0% (perfectly sealed containment system) to 100% (uncontained cold aisle). The results are used to investigate the effect of leakage ratios on the flow rates of the CRAC unit and the IT-equipment. Ultimately the effect on the inlet temperatures is also investigated. Leakage in containment system is found to have a critical effect on the containment systems performance. A threshold leakage ratio is found after which the containment system does not have benefits over the conventional uncontained cold aisle system. This approach can be used to characterize the leakage in contained systems.