Modeling racks and servers heat capacity in a physics based dynamic CFD model of data centers

This work presents the effect of servers and racks heat capacity on common dynamic scenarios in data centers. Room level Computational Fluid Dynamics (CFD) model is developed to simulate airflow rate and servers power fluctuations in a representative data center. 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 compared with models that neglects the effect of servers heat capacity. It is also found that the rack chassis heat capacity has a slight influence on temperatures rate of change, thus it can be neglected without affecting the accuracy of the results and also reducing the computational time.