Implementing rack thermal capacity in a room level CFD model of a data center

In this work, thermal capacity of servers and racks are implemented in a room level model of a data center. The effect of modeling the thermal capacity on common dynamic scenarios is demonstrated. A Computational Fluid Dynamics (CFD) server level model is developed and validated using available experimental data. The server level model is incorporated in a CFD room level model. The room level model includes all the data center main components and calibrated for internal and external pressure drops. The room level model is used to simulate the airflow rate and power fluctuations in time. It is found that the servers heat capacity has a significant effect on the dynamics of data centers. An order of magnitude increase is observed in the time constant associated with change in temperatures. It is also found that the rack chassis heat capacity has a relatively small influence on the temperature rate of change, thus it can be neglected without affecting the accuracy of the results and significantly reduces the computational time.